E L E

NEW EPSON NOTEBOOK

WITH WORDSTAR AND SPREADSHEET

SOFTWARE IN ROM!

TELECOMMUNICATIONS BREAKTHROUGH:

DIAL -UP 56 KBAUD

SYMPHONY: EASY -TO -WE INTEGRATED SOFTWARE

FOR OFFICE

PRODUCTIVITY

LINK YOUR MICRO TO ALMOST

ANYTHING v,A1F"I'Sr7,01701711-01;5

ic", .1.0 /0 fill 1:11 palf itt4

/SI 10 1,11, 1'1 fg

1.110 10 11 I-1 1-1 ri

SEPTEMBER 1984 $195

"P0111.1 ilm"T c 117".

PTE9T ed NO1Nb6HDOD T 06 LT sioso ianuis r

ObbN638X8

OTVT 96841'008 fl$ 006E0,9 PTE9T II9I0-G****************

.10

- r - AC=31,

Announcing a small imIt's 12"x 111/4"x 21/4"

It weighs less than 8 pounds!And costs less than $1,300!*

Yet with 128K, the new Apple® Ilc Per-

sonal Computer is a lot bigger than it looks.

The Ilc has 41'411 -size layboard

Because its inherited all the talentsof the eminently talented Apple He:

The versatility to run over 10,000

different software programs.The ironclad reliability of

the first true VLSI motherboard.

And the artistic ability of16 high -resolution colors.

The Ilc also has some

talents of its very own.

For instance, a

switchable 80/40-

A built-in half -high 143K single -

sided disk drive.

Built-in serial ports for modems,printers and an extra half -high drive.

Even built-inmousetronics so it's

ready to use a mouse

and all the new Apple II

mouseware.

And our newestbrainchild is certainlynot an orphan.

character display. You can grow itThin. im't it? Even

Switchable disk drive with a whole family ofQWER1Y/Dvorak keyboard. Apple 11 accessories and peripherals.

I - 01 T--...grommormunrir-

T I ard_T 'rill aro' ur," lar-a

I ! -sr' nlor" -fir -11

i IOW USA MST lila INS\

wovement on the Apple Ile.Including the newApple Scribe-Apple'sfirst full -color print -on -anything printerfor under $300, it can handle anythingfrom business graphics to term papers.

The Ilc's father, of course, is thegranddaddy of the whole personal com-puter industry, the Apple He. Which, lestwe forget, has quite a few improvementsof its own this year.

The He can now use our ProFile""hard disk- so it can store about 2400

pages of anything you'd like to remember.Anc the Apple Ile is still the most

expandable personal computer there is.

111111111111

40.1111 giowirmo.

Bunt in pork for making all the right connections.

You can increase its RAM to an elephan-

tine 512K Add a Z-80 card to run CP/M7

In fact, you can grow it with enoughcards and peripherals to run just aboutany family business. Like Saudi Arabia.

So you see, the only questionis whether you need an expandableApple II.As in He.

Or a compact Apple II. As in R.Just visit your friendly authorized

Apple dealer.

And tell them what sizeimprovement you'd like. 1111.

Dont tatffick make .3m4 suptiouc ay all get- out, 14,11. all this. one metou that the Ilc CPI alone ti lec 7 5 pounds Thpe atter pack. mon ttot an miry AO bile a printer (niche wed &Alf millmake the I lc nigh more Our tattlers utffecomernid tbat jou might not he ahle tofiguse this one out pulse! f The FTC is concerned about price S o this only a Suggested Rtlad PriceMu can pay more tbou really mint to Or law. © /984 Apple Computer lot- Apple. the Apple Iwo and PmFile are tradetarkcofAmile (impute.' Inc IM isa trademark of Digital Hamm)! IncRff an authorized Apple dealer neural jou. call (800) 538-9696. Cimada call (800)268-7706 or (800)268-7637.

DISCOVER COMPUTERS _ATARA

"You get to spend yourenergy on ideas rather thantyping:'

The AtariWriter"' programtakes the drudgery out of writingby eliminating the drudgery oftyping-worrying about typos,whiting out mistakes, retypingnew drafts over and over andover.

Spend more time writing,no time retyping.

Whether you're writing a per-sonal letter, a paper for school, areport for your club or magazinearticles for a living, AtariWriterlets you compose and edit yourtext on your TV screen, beforeyou put it on paper. Got asentence that seems out of or-der? It's easy to reposition it withAtariWriter. Would the thirdparagraph make more sense as

L ..__iii Walla

117 1111rnINLAILIK.-

AtariWriterTmmakes it easiertobeabetter writer.

the fifth paragraph? It's just aseasy to move whole paragraphsaround. Are you a miserablespeller? Add the new 36,000word ATARI Proofreader"'program and yourATARI Home

Computer will searchout spelling errors for

you. You can eveninstruct the Proof-reader programto check spelling

on technical wordsyou may need in your writing.

Not a word touches paperuntil you're sure

it's right.Remember, you've been able

to make all these changes be-fore a single word has been puton paper. You've been spendingyour time creating, not wasting ittyping draft after draft. But whenyou finally feel your writing ispolished to perfection, theATARI 1027TM Letter QualityPrinter will print out as manycrisp, clean copies as you needon plain bond paper or yourpersonal stationery. (It evenautomatically numbers pagesfor you!)

What if you suddenly find youneed more copies six monthsfrom now? No problem at all ifyou've got either the sophisti-cated ATARI 1050TM Disk Drive orless expensive 1O1OTM ProgramRecorder. These devices let you

"store" your text indefinitely, "justin case"

Here's what you need tostart writing better.

The AtariWriter word process-ing program works with anyATARI Home Computer-including the new 600XEm and800XLTM You can choose either oftwo ATARI printers: the highspeed ATARI 1025TH 80 -column,dot matrix or the ATARI 1027 Let-ter Quality model. And either oftwo text storage systems: theATARI 1050 Disk Drive or ATARI1010 Program Recorder. No mat-ter what combination youchoose you'll be paying less thanmost other word processing sys-tems.

Stop by your Atari Dealertoday and see how much easierit is to be a better writer-nowthat Atari has made it so mucheasier to write.

ALDISCOVER

WHAT YOU ANDATARI

CAN DO.0 1984 Atari. Inc All rights reserved

0 A Warner Communications CompanyCIrcI No. 9 on Free Information Card

SEPTEMBER 1984 CWORLD'SLD LARGEST COMPUTER MAGAZINE

muters&ELECTp ONICSFeatures54 Real World

InterfacesB y John ConwayDevices to link your micro with thephysical world.

60 Keyboards: The Powerat Your Fingertips

By TJ ByersThe inner workings of the primary path-way to your machine.

66 AT&T Breaksthe Speed Barrier

B y Patrick McDonnellNew technology will soon permit dial -upusers to communicate at 56,000 baud.

70 CMOS Takesthe Le

orillannosiskaawnmu. 11,4111111114114111

By uene Patterson and Ain MagosIts speed and low power consumptionare behind the new generation of lapsizecomputers.

76 Xerox PARC-Heroes of the MicroRevolution

By Martin PorterA look at the think tank where many feelit all began.

80 Tape Backupfor Hard Disks

B y Ed TejaNew products that aid in the vital back-up of fixed disks.

VOLUME 22, NUMBER 9

COVER P -10TO BY MICHEL TCHEREVKOFF

86 Engineering Designon Micros

B y Alex LeeMicros are gaining the power of expen-sive engineering design systems.

Reviews34 Epson PX-8 Lapsize

ComputerB y Joseph DespositoA 5 -pound portable that sports ROM -based WordStar, BASIC, and spread-sheet software.

42 Stearns DesktopComputer

B y BM BarrettA fast 8086 -based MS-DOS machine of-fering special function keys, other ad-vanced features.

46 Atari's Touch Tabletand Chalk Board'sPowerPad

B y Charles RubensteinTwo input devices with just the righttouch.

48 SymphonyBy Lee D. ZintskindPowerful new integrated software fromthe makers of 1-2-3.

52 NutshellBy Terry EdwardsEasy -to -use information managementfor 16 bit computers.

Columns12 Les Solomon on

Computer HardwareSurface Mounting.

24 The ComputerScientist

By Forrest M. Mims, IllAnalog computer techniques for digitalcomputers.

Deparbnents4 EditorialBy Seth R. Alpert

6 Letters

94 New Products

118 Computer Mart/Electronics Classified

124 Advertisers' Index

COPYRIGHT° 1984 BY ZIFF-DAVIS PUBLISHING COMPANY. AU rights reserved. Computers & Electronics (ISSN 0032-4485) September 1984, Volume 22, Number 9. Published monthlyby Ziff -Davis Publishing Co., at One Park Ave., New York. NY 10016. Richard P. Friese, President; Selwyn Taubman, Treasurer; Bertram A. Abrams. Secretary. One year subscription rate forU.S. and Possessions, 516.97; Canada, $21.97; all other countries, $24.97 (cash orders only, payable in U.S. currency). Second Class Postage Paid at Los Angeles. CA 9(X)52 and at additional mail-ing offices. Authorized as second class mail by the Post Office Dept.. Ottawa, Canada, and for payment of postage in cash. POPULAR ELECTRONICS including ELECTRONICS WORLDtrademark registered. Indexed in the Reader's Guide to Periodical Literature. Ziff -Davis also publishes Boating. Car and Driver. Cycle. Flying, Popular Photography. Skiing. Stereo Review,Electronic Experimenter's Handbook, and Tape Recording & Buying Guide. POSTMASTER: Send address changes to COMPUTERS & ELECTRONICS. Circulation Dept. P.O. Box 2774,Boulder, CO 80302. Please allow at least eight weeks for change of address, enclosing, if possible, an address label from a recent issue. Permissions. Material in this publication may not be repro-duced in any form without permission. Requests for permission should be directed to Jean Lamensdorf, Rights and Permissions. Zifl-Davis Publishing Co.. One Park Ave., New York, NY 10016.

September 1984 3

SETH R. ALPERT

EDITORIAL

SELECTING hardware is no easymatter. You have to consider somany things-operating system,

compatibility, availabilty of peripherals,amount of memory, and price and per-formance, to name a few. As hardwareitems continue to get more similar, how-ever, it becomes considerably less likelythat you will make a serious blunder,whatever you choose.

Choosing software can be that muchharder because even de facto standardsare absent. Typically, as you begin, youwill not even know all the selection crite-ria. Finding the right software is of majorimportance for computer owners wishingto enhance their systems. For first-timebuyers it is vital, because one reallyshould let the software choice drive thehardware choice. But for all potentialbuyers, a major software purchase canmean an agonizing decision with few reli-able sources of information. Knowingthat a bad decision can waste not onlyhundreds of dollars but countless hoursdoesn't make it any easier. Here are someguidelines that might help.

How to Choose SoftwareTo begin with, you should think care-

fully about what you want the softwareto help you accomplish and select aproduct category that seems to be aimedat your type of problem. Then decide onthe features you need for the applica-tions at hand and for conceivable futureapplications. Of course, there are all themore or less obvious things, such as easeof use, power and efficiency. In addition,there will be other features that are rele-vant only to the particular type of prod-uct that you are considering. You mightnot even know what they are, or, if youknow the buzz words, you might not un-derstand what they mean and whether

they are important. For example, does itreally matter whether your databasemanagement system is relational, what-ever that means?

The next thing to do is to acquire bet-ter information. Look at books and atmagazines (both for their articles andtheir advertisements). Asking salespeo-ple at computer stores is worth a try, butwatch out, because many of them mayknow even less than you do. Sometimesreading and talking to people helps,sometimes it simply makes things moreconfusing. If you are among the luckyfew, you have an opinionated and trust-ed friend who has the nerve to identifythe best product for your purpose. Some-one who has had hands-on experiencewith software you are considering is ide-al for this consulting.

The point is to do some research andnarrow your choice down to a handful ofproducts. Now you've got to make the fi-nal decision. Question: is it any help atall to know how well a given product isselling or how good a track record its de-veloper has? This is an interesting ques-tion, which occurred to me when I re-cently heard one of our free-lanceauthors ardently expound seeminglycontradictory positions on the subject inthe course of a single two-hour meeting.

One view is that if a product has soldin large volume-Wordstar, for exam-ple-then it has to be good, because allof those people couldn't be wrong. I amsure that there is a grain of truth in this,but of course you can fool all of the peo-ple some of the time. Thus, while volumeoffers some assurance of quality, eitherin performance or ease of use or both, itis no guarantee.

Another position is that if you knowwhere to look, you can find really greatsoftware that works and does not cost an

arm and a leg (or at least is cheaper thancompeting products). Boiled down, thetheory here is that there are developerswho have created great products butwho don't have the funding or inclina-tion to mount an advertising and mar-keting campaign and get their productson the best-seller charts. Perhaps theproduct isn't selling in volume yet be-cause the marketing blitz is yet to begin.After all, the VisiCalcs, 1-2-3s, dBase11s, and Wordstars of the world had tostart somewhere, didn't they?

I'm sure that you can see the contra-dictions inherent in these two positions.They can't both be correct, can they? Ofcourse they can!

To see how, think about the analogyof choosing a book. After you select thebroad subject matter-perhaps it is mur-der mysteries-how do you choose a sin-gle title? One approach is to check thebest-seller charts. Sometimeswith real quality, but you can just as eas-ily end up with mass -market fluff. An-other approach is to go to the classics,straight to the Agatha Christies andDashiell Hammetts of the field. Oftenyou will get a good read that way. Butgenerally, you will be missing out on allthe sex and violence found in the newerreleases. Both approaches have theirrisks. Unfortunately, you won't knowwhether you've made a good choice untilafter you have read the book.

Road Test SoftwareTo a large degree, I am afraid that the

same is true of choosing software. Yourbest hope &avoiding disappointment isto follow the general guidelines here andto do one *re thing: kick the tires andtake the prtiOuct for a test drive. Youknow what you want to accomplish, soget your retailer to let you sit at a ma-chine with a demo copy of the softwarehe wants to sell you and its manual andsee if you can get it to do some of whatyou want it to do. It will take some time,but it is worth it, and besides you willhave already limited the number ofpackages under consideration. Ofcourse, a hands-on session is not thesame as living with a product throughyour first major application. Still it is thebest way of determining, before you layout any cash, whether it suits yourunique personality and needs. 0

4 Computers & Electronics

Panasonic can help you get the maximum performancefrom your computer system. The computer has the cap-abilities you need, but to get the most out of the system,a quality professional printer is vital.

And that's a Panasonic printer.Look to Panasonic for a full line of printers, compatible

with most popular computer systems. They featurespeeds of up to 180cps, correspondence and nea--letterquality, graphics capabilities, bi-directional printing withlogic -seeking capabilities, proportional printing, ca-riagesaccepting paper 4" to 15" wide, cartridge ribbons, andadjustable tractor and friction feeds.

At Panasonic, we're very serious about the perfor-mance of our printers. Their reliability and our eKtensive

PanasonicPrinters.

We help youget it out of

your system.

service network are a direct resul- of our commitment toquality. We offe- a one-year limited warranty*, a nation-wide regional technical support retwork, and a toll freenumber. When use a Panasoric printer, you have anestabfished -1 tech manufactu-er behind you.

It's our business to offer you high quality peripherals -printers, computer displays, plotters, and data er try ter-minals. Find out how Panasonic can help you get t out ofyour system. Contact: Computer Products Division,Panasonic Industrial Company, Division of MatsushitaElectric Corporation of America, One Panason c Way,Secaucus, N.J. 07094. Call TOLL FREE 800-222-0584,in New Jersey (201) 34.8-5337.

PanasonicIndustrial CompanyCircle No. 38 on Free Information Card

1 -Year Limited Warranty. (Carry -in or mail -in service.)

Atlanta, GA- (404)925-6830; Chicago, IL -(312)364-7900; Dallas, TX -(214) 258-640J; Cypress. CA- (714)895-7413.

rs&EL ECT R O N I C S

WILLIAM S. DAVID Publisher

SETH R. ALPERT Editor

PETER COSTA Executive Editor

LESLIE SOLOMON Technical Director

JOHN R. RIGGS Managing Editor

ROBERT LASCARO Associate Art Director

JOSEPH DESPOSITO Technical Editor

JOSEF BERNARD Technical Editor

DANIEL GLADSTONE Senior Copy Editor

ANDRE DUZANT Technical Illustrator

JEFF NEWMAN Editorial Assistant

AMY MADWED Art Assistant

Contributing Editors: Sol Libes, Forrest M Mims, III,Barbara E. McMullen, John F. McMullen

Editorial and Executive OfficesOne Park Avenue, New York, N.Y. 10016.212-503-3500

Advertising Sales Offices

Eastern

Ken Lipka, I Park Ave., New York, N.Y. 10016.212-503-5029

Linda M. Holbrook, 160 State St., Boston, MA02109. 617-367-7190

Midwestern

Robert Vanek, Suite 1400, 180 N. Michigan Ave.,Chicago, IL 60601. 312-346-2600

Western

Janet Bish, 11 Davis Dr., Belmont, CA 94002. 415-594-2290

Anne Abeln, 3460 Wilshire Blvd., Los Angeles, CA90010. 213-387-2100

Southeastern

Mark Browning, PO Box 81306, 2511 Carroll Ave.,Atlanta, GA 30366. 404-455-3430.

Consumer Computers & ElectronicsMagazine Division

Larry SpornJeff HammondCarole Mandel

Eileen G. Markowitz

Jerry Schneider

Herbert Stern

Jonathan D. LazarusPeter J. Blank

PresidentVice President, MarketingVice President, CirculationVice President,General ManagerVice President, Licensing& Special ProjectsVice President, CreativeServicesEditorial DirectorCreative Director

Ziff -Davis Publishing

President Richard P. Friese; President ConsumerMagazine Division Albert S. Traina; ExecutiveVice President, Marketing and Circulation Paul H.Chook; Senior Vice President Phillip T. Heffernan;Senior Vice President Sidney Holtz; Senior VicePresident Edward D. Muhlfeld; Senior Vice Presi-dent Philip Sine; Vice President Baird Davis; VicePresident George Morrissey; Vice President RoryParisi: Vice President William L. Phillips; Treasur-er Selwyn Taubman; Secretary Bertram A. Abrams

Editorial correspondence: COMPUTERS &ELECTRONICS, I Park Ave., New York, NY 10016.Editorial contributions must be accompanied by returnpostage and will be handled with reasonable care; how-ever, publisher assumes no responsibility for return orsafety of manuscripts, art work, or models submitted.

The publisher has no knowledge of any propri-etary rights which will be violated by the making or us-ing of any items disclosed in this issue.

ABC Ci)Month., Awl., Bu,...1Of Corculat.o.,t

LETTERS"Documentation Is a Paini"

As a technical writer for more than 10years, I have heard the words abovefrom engineers and managers moretimes than I care to remember. So Ithink Les Solomon was right on target inhis "Computer Hardware" column forMay, "Logic is Our Business and Busi-ness Could Be Better," when he identi-fied the need for better manuals.

Before we line up our sights on thepublications department, however, let'sidentify the causes of poor technicalmanuals.

First is upper -management percep-tion. Too often the manuals are treatedas afterthoughts or "necessary evils."The successful company identifies docu-mentation as an integral part of the over-all product.

Second is poor product developmentscheduling. Even if documentation isconsidered in the schedule, last-minutechanges in software and other aspects ofthe equipment are often made just as theequipment is being crated for shipment.Adequate lead time is needed to creategood manuals.

Finally, there is lack of engineering in-put. Most engineers have an aversion towriting. Yet, even the crudest engineer-ing log is an invaluable source of infor-mation to a technical writer.

Good documentation is possible, andthe customer should settle for nothingless.

-DAVID NOTTKEOak Park, IL

No Y for CipherI have some corrections to your article

in the June 1984 issue concerning crypto-graphic security.

The glossary on page 93 is incorrect ina couple of definitions. Cryptology is themain subject, which is divided into cryp-tography and cryptanalysis. Cryptogra-phy is the science of producing ciphersfor one's own use. Cryptanalysis is thescience of breaking other's ciphers.

The greatest error is the spelling of"cipher." Where that "y" came from is amystery to me. It makes one wonder ifthe authors are really educated in cryp-tography if they don't know how to spell"cipher."

When I was in the Navy and State De-partment engaged in cryptography weoften got ciphers (for sale) from "inven-tors." Almost invariably the letter

would close with a statement somewhatas follows: "Even I, the inventor, cannotbreak it."

-RALPH V. ANDERSONHolton, KS

Cypher is a British variant on cipher.Sorry for the inadvertent encryption.

-Ed.

Adam EnthusiastWhen reading Forrest Mims's column

"Experimenting with Coleco's Adam"in your April issue, I was glad to see thatsomeone felt the same way about theAdam that I do. My family has ownedone for approximately four months, andI am constantly discovering new capa-bilities that Adam has.

Although I am only 13, I have beenaround computers for many years andreally enjoy programming. I am veryknowledgeable of the many commandsand control keys used in programmingthe Adam. I also find the built-in wordprocessor to be of good quality and easyto use. I have used it for everything fromtyping letters to writing reports.

-DOUG DUSSAULTBurlington, WI

Kaypro 4 Plus 88In his article "Kaypro 4 Plus 88"

(March, p 79), Charles Rubensteinclearly outlined the capabilities of theKaypro 4 with the additional 8088coprocessor. However, I would like topoint out a mistake in the article regard-ing the use of the RAM disk. He saysthat the RAM disk feature allows pro-grams to have rapid I/O without the ex-pense of a hard disk. "It is only imple-mented when requested; and, since it isdynamic RAM, it is reset whenwarm/cold booted."

My experience is that the RAM disk isnot reset when it is warm booted-onlywhen it is cold booted. This is an impor-tant point because it allows the user tochange disks in the two disk drives andwarm boot the computer without havingto reload the RAM disk.

-ED O'CONNELLElmira, NY

Disk CorrectionIn the July issue, the disks shown in the

article "Store It with Light" on page 63should have been identified as being fromStorage Technology Corp. and OpticalStorage, Inc. -Ed.

6 Computers & Electronics

THE SHARI' PC -5000

Finally, Sharp's PC -5000 puts desktop comput_ng where it's neverbeen before. In the field. Now you can do word processing on the train,information management on site and spread sheet analysis in your hotelroom. You can now communicate with mainframes and databases. Plus,it's designed so it can easily be integrated into your systems.

Specifications: Weighs under 10 Ihs!/31/2"H x 12"D x 13"W 16 -bit, 8088 CPU/128K expandable to 256K RAM Two 51/4 floppy drives/320K each** Integrated 37 CPS whisper -quiet corresponcence-

quality printer** MS-DOS" operating system/IBM" compatiDility Fold -down display for briefcase transporting(

8 lines x 80 columns 6 -hour rechargeable battery Software offering-number processing,

word ocessing, communications andinformation management

Direct connect modem** Nationwide service program Immediately availableSo before you decide to buy a

computer that's not going anywhere,look into Sharp's PC -5000. Itgoes everywhere!

For more informationjust call toll -free1 -800 -BE SHARPor send in thecoupon.

**Options.

printer and InodanMS-IX/S. registered trademark ol toerykationIliM rs a registered trademark oi International liminess .Stahtnes t wpm -AkinSharp Electronics Lore , Paramus. N J 0.7652

Circle No. 4 on Free Information Card

rSharp ElectrooL-s Corp., 11118E Cornell, Peoria, IL 16114Please send me more information 'bent Sharps PC -5000Please set up a desxmstration

Name Title

Crimpens

Street_

City State

SHARPZp

FROM SHARP MINDSPhe,. COME SHARP PRODUCTS

Warn robotics andyou build thisNew NRI home trainingprepares you for a rewardingcareer in Americas newesthigh-technology field.

The wave of the future ishere. Already, advanced roboticsystems are producing every-thing from precision electroniccircuits to automobiles andgiant locomotives. By 1990.over 100,000 "smart" robotswill be in use.

Over 25,000 New JobsKeeping this robot army

running calls for well -trainedtechnicians . . . people whounderstand advanced systemsand controls. By the end of thedecade, conservative estimatescall for more than 25,000 newtechnical jobs. These are thekind of careers that pay$25,000 to $35,000 a year rightnow. And as demand continues

to grow, salaries have no placeto go but up!

Build Your Own RobotAs You Train at Home

Now, you can train for anexciting, rewarding career inrobotics and industrial controlright at home in your sparetime. NRI, with 70 years ofexperience in technologytraining, offers a new world ofopportunity in one of the mostfascinating growth fields sincethe computer.

You need no experience,no special education. NRIstarts you at the beginning,takes you in easy -to -follow,bite -size lessons from basicelectronics right on through

You get and keep Hero 1 robot with gripper arm and speech synthesizer, NRIDiscovery Lab for electronic experimentation, professional multimeter with31/2 -digit LCD readout, 51 fast -track training lessons.

key subjects like instru-mentation, digital and com-puter controls, servomotorsand feedback systems, fluidics,lasers, and optoelectronics.And it's all reinforced withpractical, hands-on experienceto give you a priceless con-fidence as you build a program-mable, mobile robot.Program Arm and BodyMovement, Even Speech

Designed expecially fortraining, your robot dupli-cates all the key elements ofindustrial robotics. You learnto operate, program, service,and troubleshoot using thesame techniques you'lluse in the field. It'son-the-job train-ing at home!

industrial control asBuilding this exciting

robot will take you beyond thestate of the art into the nextgeneration of industrialrobotics.

You'll learn how yourcompletely self -powered robotinteracts with its environmentto sense light, sound, andmotion. You program it totravel over a set course, avoidobstacles using its sonarranging capability. Programin complex arm and bodymovements using its specialteaching pendant. Build awireless remote control devicedemonstrating independentrobot control in hazardousenvironments. You'll evenlearn to synthesize speechusing the top -mountedhexadecimal keyboard.Training to Build a

Career OnNRI training

uniquely incorporateshands-on building

experience to

Armprovides 5axis ofmotion.

Steppermotorsrotate armand wrist,extend(giver up

Rechargeablegel-typei: forindependentoperation.

Hexadecimalkeyboard forprogrammingknd modeelection.

Teaching pendantand remote controlprogram movement.

Sensesmotion,sound, light,dista ice.

Plug- ncircuit boardsfor convenientexperimenta-tion andmain' enance.

Front-wh,e1drive with12 -Inchturningradius.

Your mobile robot duplicates functions of state-of-the-art industrial units.

reinforce your learning on areal -world basis. You get profes-sional instruments, including adigital multimeter you'll use inexperiments and demonstra-tions, use later in your work.And you get the exclusive NRIDiscovery Lab®, where youexamine and prove out theoryfrom basic electrical conceptsto the most advanced solid-state digital electronics andmicroprocessor technology.Devised by an experienced

team of engineers andeducators, your

experiments,demonstrations, andequipment arecarefully integratedwith 51 clear andconcise lessons togive you completeconfidence as youprogress. Step-by-step, NRI takes youfrom the beginning,through today, andinto an amazingtomorrow.Send for FreeCatalog Now

Send for NRI'sbig free catalogdescribing Roboticsand IndustrialControl plus over a

dozen other high-technologycourses. You'll see all theequipment you get in detail,get complete descriptions ofevery lesson, find out moreabout career opportunities fortrained technicians. There'sno cost or obligation, so sendtoday. Your action today couldmean your future tomorrow.If the card has been removed,please write us today.

NRI ' SCHOOLS

1114 FA McGraw-Hill ContinuingEducation Center

.A 3939 Wisconsin Ave.Washington. DC 20016

WE'LL GIVE YOU TOMORROW.

LES SOLOMON ON

COMPUTER HARDWARESURFACE MOUNTING

pDINT -TO -POINT wiring, the com-ponent interconnection techniqueused in the very early days of the

electronics industry, was superseded bya vastly improved approach called the"printed circuit," or "pc," board.

The "wiring on a board" techniqueeliminated intercomponent cabling andallowed more components to be mount-ed and interconnected in a relativelysmall space. Since each pc board is theo-retically identical to the original engi-neering model, another benefit was a re-duction in wiring errors.

Printed circuit construction becamethe backbone of the electronics industrybecause it not only allowed for machine

creation of the pc board itself, it also per-mitted machine installation of the vari-ous discrete components that made upthe circuit. Manufacturers were there-fore able to mass produce their productsand greatly reduce manufacturing andselling costs.

The pc approach reached its peakwith the mounting of the integrated cir-cuit within the familiar multi -pin dual -inline package (DIP). This combinationappears in all types of electronic systemsranging from test instruments to suchconsumer items as radio, TV, and audioequipment to computers and their asso-ciated plug-in devices.

We are now on the verge of the nextevolutionary step in electronic productconstruction, one that may force theubiquitous pc board to join point-to-point wiring in history. This new tech-

nique, called "surface mounting," willalso generate great changes in the elec-tronics industry, particularly withmicrocomputers.

Although "surface mounting" maynot be a familiar expression, it has beenhiding among us for quite a while.

Where has it been? On your wrist, in-side your digital wristwatch, and in yourpocket, in a low-cost calculator.

Take a look at a typical low-cost digi-tal watch or calculator and try to visual-ize the complex electronics that must bein it to accomplish the broad range offunctions that come in the slim littlepackage. Then consider the price, the re-liability, and the power supply!

Today, you can buy, for a few dollars,a battery -powered pocket calculatorhaving functions that exceed many ofthe million -dollar computers used inWWII. In fact, imagine what a compara-ble watch or calculator would have costonly a few years back?

One usually unconsidered fact aboutthese low-cost digital devices is that inmost cases it is cheaper to buy a newwatch or calculator than it is to get onerepaired (sometimes to even buy newbatteries). At least as far as watches andcalculators are concerned, we live in theage of "throwaway" electronics.

If you have a defunct digital watch,open it and observe the "pc board." Youwill note that it looks quite differentfrom the multi -IC, dense, conventionalpc boards used in physically larger elec-tronic systems such as personal comput-

ers. In fact, you may not recognize anycomponents on the board.

The surface -mounting technique al-lows all the components to be machinemounted (actually soldered) on one sideof a support substrate and accounts forthe low cost of the item.

The ICs may be difficult to recognizesince they do not come in the familiarmulti -pin DIP packages, but appear asflat pellet -like "chips" whose metal"lands" (the inputs and outputs of theIC) are directly soldered to the conduct-ing pattern of lines deposited on the sur-face of the support (usually ceramic)substrate and protected by a thin layer ofplastic.

All the other surface -mounted com-ponents also appear in pellet form, witheach component lead directly solderedto the substrate pattern. Because of thisnew fabrication technique, you will findit difficult to identify a resistor, capaci-tor, or transistor. Even the LCD displayis of "minimal" manufacture.

But, no matter how it looks, thesystem works as advertised and is ex-tremely safe from damage due to shock,vibration, and moisture. Since very low-

power CMOS (and its derivatives) areused to create the semiconductors, andthe device uses a very low -power LCDreadout, the power source can be one ortwo physically small, low-cost cells.

Let us look at another area.Many new multi -function ICs now

starting to appear are actually formedfrom several "chips" of tried -and -testedconventional ICs, all mounted and in-terconnected on the same substrate toproduce a single, complex IC. This ap-proach could be called the semiconduc-tor version of surface mounting.

In the area of small size, keep in mindthat when you look at most discrete elec-tronic components, you are actuallylooking at a package that is much largerthan the component it protects. Youmay be surprised how small an IC reallyis if you break away the plastic case andlook at the actual chip (try it using a de-funct IC).

The same size reduction can also oc-cur in many other components associat-ed with ICs. For example, when operat-ing voltages and powers are very low (asthey would be in a CMOS circuit), ca -

12Computers & Electronics

WHAT WOULD YOU SAYTO A NEW LAP -SIZE COMPUTER

WITH SEXY GOOD LOOKSLIKE THE APPLE Mc AND

BONE CRUSHING POWER LIKETHE $3000 H -P PORTABLE,

ALL FOR $995?

r

""

. -Ad.

ar.

:*r,r

Of course you want it.The Epson Geneva. A full -function, battery

powered lap -size computer with 64K of memory, an 80character 8 -line screen, a big, .-esponsive keyboard,cassette storage, plus four powerful, popular pro-grams on ROM capsules, all included free.

All Epson quality. All for $995.Now that's technology.If the Geneva is small where it counts, it is

also big where it counts. In software, you get thebig advantage of a universal operating system-

CPIM And tostart you off atfreeway speed, theEpson Geneva

comes completewith WordStar

Aiso includedis PortableCa'c, anelectronicsp,-ead-

sheet, Portable Scheduler,and Microsoft BASIC.

Want more?The Epson Geneva offers a

complete collection of advanced,battery -powered mini -peripherals.Customize your perfect computer

EPSON

arimaill. VIEW /414/04.1

r-

WNW

7A Cf

C ,'

H/f T

7

a.

Q W a Pi T V

0

z X

CAGESLUCk

E S 0 N

Geneva

-4111111

s.

11 +

4g. 21P

saik.

-; lc1111 ink

UM 11lk11111111411111*

1111k

system w,th a direc7 connect modem; an extra 120K ofRAM disk memory, a 320K31: disk drive; there's evenan amazing four pound 80 -column printer

Llere:s the best part.When you put an EpsonGeneva and every one of ,

these peripherals intoone briefcase, /ouhave a complete jcomputer systemfor a thousanddollars less thanwhere other powerfulportables begin.

The Epson Geneva. You know you want it,so when are you going to get it?

For the name of your nearest Epsondealei call (800) 421-5426 In CA, call(213) 539-9140

- '

NEVER HAS

'OUGHT SO MUCH. AND SO LITTLE.

Epson Apple WordStar CP M and Microsoft a -eregistered trademarks of Epson Corporation AppleComputer Inc MicroPro. Digital Research andMicrosoft Corporation respectively Geneva istrademark of Epson America Inc

G E lark' V A

pacitors and resistors can exist in verysmall semiconductor chip form, ready tobe surface mounted (soldered) alongwith the IC chips.

Thus, a number of chips and otherelectronics components can be intercon-nected to form a "surface mounted" sys-tem. The reliability of this technique isso high that many manufacturers com-bine and interconnect a number of chipson one substrate, and the assembly doesnot have to be electrically tested.

Because of the low manufacturingcosts, if a board using surface mountingfails during its checkout, it is cheaper tothrow it away and replace it with anoth-er, similar, board rather than go throughthe expense of troubleshooting, remov-ing, and replacing one chip. This is simi-lar to what is done today with a low-costdigital watch or calculator.

We have come to the point in our cur-rent technology where the semiconduc-tors are more reliable than the socketsthat some computer manufacturers stilluse. That is why, in present-day systemsusing conventional DIP semiconduc-tors, you see more soldered -in semicon-ductors and fewer and fewer sockets.

On the other hand, passive compo-nents, such as resistors, capacitors, andinductors, which are more tolerant ofhigh temperatures than semiconductors,have always been directly soldered to thepc board.

There is one potentially dangeroushitch to the solder -in technique. The actof high -temperature soldering an IC to aboard (as used at present) has damagedmore ICs than almost anything else. Sol-der can crack due to the difference inthermal expansion between the compo-nent and the board pads. Also, the com-bination of solder and the metal used forthe traces can leach, which may be a po-tential source of short-circuits.

This is one of the reasons manufactur-ers are looking for other soldering andbonding techniques, particularly for sur-face mounting.

One manufacturer is experimentingwith a surface -mounting technique thatuses conductive epoxy to form the "foilpattern" which is screen printed on thesubstrate (similar to the copper traces ona conventional pc board). Then, small"dots" of non-conductive epoxy areplaced on the substrate where the vari-ous pellets will be placed. When the sub-strate, with components, is subjected toa temperature of 150 to 200 C, both ep-oxies cure, and the surface mounting iscomplete. This technique eliminates therelatively expensive pretinning, prebak-ing, and flux -removal steps conventionalcopper-trace/solder pc boards need.

Although at present more expensivethan soldering, the use of epoxies re-quires less expensive mounting equip-ment. As an added benefit, since electri-cally conductive epoxy is not rigid, thefinished surface -mounted boards cantolerate a higher thermal cycle duringlong periods of operation in a small en-closure having a minimum of heatexchange.

Another company is testing a tech-nique called "vapor -phase" to be used ina reflow solder mode. In the reflow ap-proach, the pellet lands and their associ-ated contacts on the substrate are coatedwith solder. The hot vapor penetratesbetween the densely packed board com-ponents causing the solder to melt. Theresulting solder reflow makes the electri-cal and mechanical connections.

Surface mounting also allows the useof double -sided substrates, with eachside having a completely different andindependent function, since there are no(unwanted) interconnects between thetwo sides of the thin substrate. For ex-ample, one side may carry the CPU, I/Oports, and various control chips, with

Surface mountinghas been hiding

at theend of your armin your digitalwristwatch

RAM and ROM chips on the other side.When required, interconnections be-tween the two sides would be via minuteelectrically conductive plated holes inthe substrate.

Now consider a portable computer us-ing surface -mounting techniques. Thesmallest useful physical size of such asystem is determined by the display, key-board, and mass storage system. Ofcourse, this is true today with the cur-rent crop of battery -powered "lap"computers.

The major difference is that using sur-face mounting, it becomes possible tocreate a battery -powered lap portablehaving all the attributes of present-day lap and conventional line -powered"desk mounted" microcomputers, in-cluding many megabytes (yes, mega-bytes) of internal RAM.

Such large mounts of memory for alap computer can come via two routes.

The first is when a semiconductor

manufacturer mounts and interconnectsa number of "chips" of a known goodmemory device on the same substrate toproduce a single physically small devicehaving a considerable number of bytes.

As 256K -bit RAM devices becomemore available, you will not need toomany of these small substrates to createquite a large memory. Due to the smallphysical size of such a composite "superchip," the lap computer can use many ofthese devices, thus allowing many mega-bytes of memory.

Large memory capacities will alsocome from semiconductor research. Forexample, IBM recently fabricated a 1 -megabit DRAM (dynamic RAM). All ittakes is eight of these to form a 1 -mega-byte memory for a personal computer.Don't look for this RAM to come on themarket for a while as it is still in the de-velopment stage (also, the "chip" issomewhat unwieldy). Similar high -den-sity semiconductor research is being per-formed in Japan.

Besides allowing maximum memoryfor the computer, these massive amountsof storage in a small space will also allowthe use of "semiconductor disks," thuseliminating the attendant noise, size,weight, and power requirements of con-ventional mechanical disk drives, eventhe upcoming "third -height" drives.

If transportable data storage and/or"canned" software is desired, the remov-able storage medium could well be inmicrocassette form, a magnetic tape ap-proach that holds several hundred kilo-bytes on a very small cassette using avery small low -power cassette drivesystem.

Besides small size and very low powerrequirements, another major benefit thatcomes with surface mounting is thatwhen tried and tested "chips" are com-bined with the surface -mount approach,the result will be much better electronicsystem reliability.

Since all components on the surface -mounted boards will be operated wellwithin their voltage and signal specifica-tions (they will be battery powered) andhopefully within their specified environ-mental conditions, the mean time beforefailure will be very long-possibly long-er than the lifetime of the user. If thissounds far fetched, consider the punish-ment that a digital watch takes during itslifetime, yet "it keeps on ticking." Com-pare this with the treatment that a moreexpensive portable computer will get.

In the rare event that a system does godown, it will simply be a case of replac-ing the faulty board and throwing theold one away. That will be the legacy ofsurface mounting. 0

16 Computers & Electronics

Introducing me softwarethat makes communications

apiece °Mike.

gisyLink#3niMoilManager

EasyLinl?" InstantMail' Manager softwareis probably the onlycommunicationspackage you'llever need.Designedto blend inperfectlywithWesternUnion'sEasyLinkservice, itmakes the totalcommunicationprocess easy, instant, andautomatic too.

All the right Ingredients.EasyLink Instant Mail Manager works with

EasyLink service to provide automatic access andtransmission of almost any type or length corre-spondence over the EasyLink network. So sendingmail instantly to virtually any other phone -equippedPC or word processor is a snap.

You can even reach people without equip-ment. Thanks to EasyLink's instant access to WesternUnion's Worldwide communications services.

EasyLink Instant Mail Manager also lets youaccess your company's computer or connect in-stantly to other business and information services.

The frosting on the cake.EasyLink Instant Mail Manager is more than

simple "send and receive" software. With it, you alsohave complete word processing capabilities. So youcan easily create, edit and change the format of

0 1984 Western Union

w

irvirg-rive-weviirvlwArer:

your correspondence, thensend it without ever

changing software.And, unlike

most other communi-cations software,

EasyLink InstantMail Manager

allows you tocreate andmanage apermanent

electronic address filethat stores hundreds of names

and addresses. So you can instantly speedcorrespondence to anyone. Anytime.

Ifyou need It, getting help Is sweetand simple.

EasyLink Instant Mail Manager is set upto guide you step by step. From how to formatmessages to how you go about sending them.

EasyLink Instant Mail Manager softwareand EasyLink service. The perfect mix.

Available now at your computer softwaredealer or call 1-800-336-3797 ext.1008 for moreinforma-tion.

Western Union

EaSY*Link

4fs4%.

dol

Available fix the IBM PC and compatible equipment.

17September1984

At CIE,you get electronicscareer training from specialists.

If you're interested in learning how to fix air conditioning,service cars or install heating systems- talk to some otherschool. But if you're serious about electronics... even earning anAssociate Degree... come to CIE -The Electronics Specialists.

Why trust your educationand career future to any-thing less than a specialist?

You shouldn't. And youcertainly don't have to.

If you talked to some of ourgraduates, chances are you'd finda lot of them shopped aroundfor their training. They prettymuch knew what was available.And they picked CIE asnumber one.

Be sure to shop around.Because, frankly, CIE isn't foreveryone.

There are other options for thehobbyist. If you're the ambitioustype-with serious career goals inelectronics-take a close look atwhat we've planned for you at CIE.What you should lookfor first.

Part of what makes electronicsso interesting is it's based onscientific discoveries-on ideas!So the first thing to look for is aprogram that starts with ideasand builds on them!

That's what happens with CIE'sAuto-Programmed®Lessons.Each lesson takes one or two prin-ciples and helps you master them-before you start using them!How practical is thetraining?

This is the next big importantquestion. After all, your careerwill be built on what you can do-and on how well you do it.

Here are ways some of CIE'scareer courses help you get your"hands-on" training...With CIE's PersonalTraining Laboratory...you learn and review the basics-perform dozens of experiments.Plus, you use a 3 -in -1 precisionMultimeter to learn testing,checking, analyzing!When you get your own5MHz, solid-stateoscilloscope, you take somereal professional steps. You useit as a doctor uses an X-raymachine-to "read" waveformpatterns...lock them in...study,understand and interpret them!When you get your DigitalLearning Laboratory, you'll

be into digital theory-essentialtraining today for anyone whowants to keep pace with the stateof the art of electronics. WithCIE's Digital Lab, you'll beapplying in dozens of fascinatingways the theory you've learned.For example, you'll compareanalog and digital devices. You'lllearn to make binary to decimalconversions and to work withsemiconductor devices andcircuits. You'll see how digitalequipment is vital to today'sexciting, growing fields such assecurity... where digital theoryprovides the brains for space-agealarm and protective devices.You'll build your Microproc-essor Training Laboratory,a working microcomputer-from"scratch." You'll also learn howto program and interface it withdisplays, memories, switches,and more.Earn An Associate Degreefrom CIE.

One cf the best credentialsyou can have in electror.ics-or any other career field-is a college degree. That'swhy CIE gives you the op-portunity to earn anAssociate in AppliedScience

rumCIE

in Electronics Engineering Tech-nology. Any CIE career coursecan offer you credit toward thedegree...more than half of thenumber needed in some cases.

You can also prepare for thegovernment -administered FCC(Federal CommunicationsCommission) RadiotelephoneLicense, General Class. It can bea real mark in your favor...government -certified proof ofyour specific knowledge andskills.Shop around...but send forCIE's free school catalogfirst!Mail the card. If it's gone, cut outand mail the coupon. If you preferto write, mention the name anddate of this magazine. We'll sendyou a copy of CIE's FREE schoolcatalog-plus a complete pack-age of independent homestudy information! For yourconvenience, we'll try to have arepresentative contact you to

answer your questions.Mail the card or coupon-or write: CIE, 1776

East 17th St.,Cleveland,

OH 44114.

Cleveland Institute of Electronics, Inc.1776 East 17th Street, Cleveland, Oh,o 44114

Accredited Member National Home Study Council

YES... I'm shopping around for the right kind of career training in electronics -and CIE sounds well worth lookinginto. Please send me my FREE CIE schoolcatalog-including details about the Associate Degree program-plus my FREEpackage of home study information!

Print Name

Address Apt

City State Zip

Age Area Code/Phone No

Check box for G.I. Bill information: Veteran Active Duty

MAIL TODAY! PE -19

SOL LIBES

BITS &BYTES

Apple Juice Apple reports that the Macintosh is

so successful that the company has be-gun plans for a second highly automatedfactory to make the system. When thisplant comes on line in 1985 Apple ex-pects to be making 4000 Macs a day. Ap-ple claims Mac production is so highlyautomated that labor costs only 1 to 2percent of the total. We were told Applehas set a goal of shipping 400,000 Macsby year-end; if the goal is met, the 350employees in the Mac group will get anextra month's salary.

Apple also disclosed that it is planningto release a Mac version with a hard diskand 512K of memory (the current unit

has 128K). The larger memory sizewould permit Apple to release a concur-rent DOS for the unit. The unit, current-ly called "the Fat Mac," would includehigher -speed serial ports (the currentunit has two ports) running at up to 5MHz (current maximum is 1 MHz) thatcan better support an external hard disk.When Fat Mac is released (for around$3000) the price of the standard Mac isexpected to drop under $2000.

It looks like Apple is working towardmaking the Lisa and Mac brands into"full product lines." Apple also appearsto be working on versions of Lisa andMac based on the Motorola 68020 mi-croprocessor. The 68020 is a true 32 -bit

CPU with memory management andother features that can better supportmulti-tasking/multi-user environments.

Apple seems to be starting a sales pro-gram with colleges willing to order atleast $1 million of Lisa and Macintoshmachines for faculty, staff and students.They will give discounts of at least 35%.IBM and DEC are reportedly offering50% to 70% discounts to schools plac-ing large orders.

Rumors also have it that Apple is ne-gotiating with AT&T, Wang Laborato-ries and NBI to sell the Lisa and Macin-tosh systems to large corporate accountson an OEM basis. AT&T would sell ver-sions of the Mac with an integratedphone via its phone centers. This is seenas an admission that Apple had donepoorly, against IBM, in selling the Macand Lisa to the Fortune 500 market. Ap-ple, which has 100 people in its nationalaccounts sales force, stated over a yearago that it planned to increase the staffto 200-300 by this time.

The Case of the ROMIessMicros, etc.

A trade association from Taiwanhas asked President Reagan to veto a re-cent International Trade Commissiondecision to ban the import of ROMlesscounterfeit Apple computers into theU.S. They claim the decision would im-pede legitimate international trade. Ac-cording to Apple, these machines are

Rumors & GossipChuck Peddle, developer of the

6502 microprocessor and early Commo-dore computers and until recently presi-dent of Victor Technologies, is back in

year-end. The unit HP will use is be-lieved to be the one that Apple andGavilan Computer will be using in theirsystems. . . . A daisywheel printer inter-face for the Macintosh is supposed to be

duce next year and to offer them to othercomputer makers. . . . There are reportsthat Eagle Computer is having problemswith cash flow and poor sales and is con -sidering some layoffs. . . . We hear that

business. He has formed an R&D corn- in development by Apple. . . . Rumors Digital Research will soon releasepany in Scotts Valley, CA. . . . Atari, we have it that IBM is developing a new "Crystal" a software developer toolkithear, is ready to introduce the 7800, a home computer system using the with many routines that can be mergednew, improved, video game compatible Microsoft MSX operating system. . . . and integrated into programs to reducewith the popular 2600. (Atari is estimat- Recently, Bill Gates, Microsoft presi- development time and to provide suched to have sold more than 15 million dent, said that the IBM has "a year or features as menus, graphics and multi -2600 models.) . . . Sharp is reported to two to go" before 80286 technology tasking. . . . With sales of the PCjr notbe showing samples of a new electro- takes over as the prevailing microcom- measuring up to expectations, IBM is re-luminscent display panel to several corn- puter standard. . . . It's in the air that ported to be considering selling the jr inputer manufacturers. It is 80 characters IBM is working on a notebook -sized mass market outlets. . . . Finally, IBMX 25 lines, 1.5" thick. Hewlett-Packard portable computer using the 8088 with lap -size portable rumors keep comingis rumored negotiating with Sharp to use bubble memory and a single disk drive. down the grapevine. The latest origi-the display in its kneetop computer,which currently has an 80 x 16 display.

. . . IBM is said to be also developing a31/2" hard disk drive storing 20M bytes.

nates in Europe, where they say IBM istesting a machine made by Matsushita

HP expects to be the first to use the de- They are expected to use these new "mi- with bubble memory, ROM softwarevice; introduction may come before cro-Winchesters" in systems they intro- and a display of 8 lines by 80 characters.

ART BY CARL WESLEY22 Computers & Electronics

copies of Apple II computers in all re-spects expect the copyrighted ROM,which is installed after the units enterthe U.S.

The U.S. Customs Service, in Seattle,recently seized a large number of alleg-edly counterfeit copies of the IBM PC,after IBM registered its copyright withCustoms and identified the copies. IBMis following in Apple's footsteps in at-tempting to protect its copyrights.

Law's Clause Draws Roars Japan is in the process of enacting a

new software protection law that placescontrol under the Ministry of Interna-tional Trade and Industry (MITI) ratherthan under the courts, as in this country.This change, viewed as an incentive forJapan's developing software industry, isfeared by some in the U.S. softwareindustry.

Under the law, developers will furnishMITI with copies of their programs.MITI will examine each for originalityand performance quality, register themfor a period of 15 years, and arbitrate alldisputes.

The U.S. is currently complaining toJapan that this new law is highlyprotectionist.

Random News Tandy may begin protecting its

software products from being copiedwith a system called "Prolock." Prolockuses a laser -aided technique to "finger-print" disks physically. It is expected tobe used this fall on educational softwareproducts. . . . The National SecurityAgency is reported to be installing a$100 million speech recognition com-puter system to monitor phone commu-nications and detect "subversive" behav-ior. . . . Sharp has announced a $350four -pen plotter with both parallel andserial interfaces. . . . Apple is also ex-pected to introduce a laser printer for theMac using the Canon mechanism. . . .

Saber Technology Corp., Anaheim, CA,has announced the highest -resolutionCRT display system yet. It can display1664 x 1248 pixels on a 19" screen.The

unit uses a 6 -MHz National 32032 -basedprocessor. To store all the display infor-mation, 2M bytes of memory are needed.

. . . Mitsubishi Electric of Japan has dis-closed its development of a new slimmerpancake motor for disk drives that is ex-pected to reduce the size of 31/2" and5'/4" floppy disk drives. . . . Dataquest,a market research outfit, reports that lastyear notebook -sized computers made up3% of systems sold, a number they pre-dict will rise to 7% this year and to 30%by 1988. . . . Sony has introduced a colormonitor using its Trinitron CRT, that itclaims will display 1280 x 1024 pixels.

PC for Four IBM, we hear, is beta -testing a

multitasking version of MS-DOS fortheir forthcoming 80286 -based system.We expect an announcement on this newsystem from IBM before year-end andinitial system shipments next year.

Digital Research (DRI), however, gotthere first. It has been delivering a multi-processing DOS with PC -DOS compati-bility since July. The product, calledConcurrent PC -DOS, will run up to fourPC -DOS or CP/M tasks concurrentlyon a standard PC. It contains a truewindowing system and communicationssupport. DRI has also introduced aplug-in board for the PC that turns Con-current PC -DOS into a system that willsupport up to four users. The board andassociated software is called "StarLink."It appears that DRI has a lead of 6 to 9months over IBM's introduction of amulti-user PC system.

An LCD in Color scii,,, histiumcnts and Electronics,

Ltd., Japan, may be producing a newmultiple -color liquid crystal display forpersonal computer use. Called theFT1616, the LCD will display eight col-ors on an array of 64 x 160 pixels (pic-ture elements). The unit is 170 x 100 mmoverall by 200 mm thick and includesthe drive electronics and a fluorescenttube for backlighting. The display area is105.6 x 42.4 mm. A 64 x 240 pixel dis-play is expected to go into productionthis fall. A unit 640 x 200 pixels (the sizeof the display used in the IBM PC) is indevelopment for possible introductionearly next year.

Quotation of the Month From John Roach, president,

Tandy/Radio Shack: "We are in a tech-nology industry where promotion anddistribution are more important thantechnology."

Getting Junior to Sell As we have mentioned in the last

two colums, sales of PCjr have been dis-appointing. One survey reports thatstores handling the units have been sell-ing an average of only four systems amonth and are left at month's end withan average of 13 units unsold. Anothersurvey that had estimated that IBMwould ship more than 500,000 jrs in1984 has slashed the figure. In May theyanticipated sales of only 100,000 units.Changes IBM has been implementingsince the late spring might, however,raise sales figures to 200,000 for the year.IBM has already lowered PC prices;more enhancements are in the works.The company has notified dealers thatthey will receive credits for units theyhave bought at full price, including unitsalready sold, and will be rebilled later.IBM has also eliminated cancellationpenalties and finance charges dealerswere responsible for in handling jrs.How is that for dealer protections?

To attract more business users, IBMmay be offering as options an improvedkeyboard and a second disk drive. It alsolooks like advertising for the jr will be-come more oriented to business andmore extensive.

In addition, IBM is hoping to boostsales by encouraging software houses tobring out programs for the jr as quicklyas possible.

Reports have reached us that IBM hassent out requests for quotations on PCjrparts for 1985 production that indicatethat the company plans to build 1.5 mil-lion units next year. (It appears that theyordered enough PCjr parts for 3 millionunits this year.)

The question now is: Can thesechanges in hardware and advertisingovercome the PCjr's slow start.

September1984 23

FORREST M. MIMS III

THE COMPUTER SCIENTISTANALOG COMPUTER MaINIQUESFOR DIGITAL COMPUTERS

Now that incredibly powerful,low-cost digital computers havebecome commonplace, it's easy

to overlook the importance of the vener-able analog computer. Indeed, most us-ers of today's personalized digital com-puters know little or nothing aboutanalog computing.

As a longtime analog computer en-thusiast, I'm happy to report that analogcomputers are alive and well in 1984. Inthis two-part series I'll cover analogcomputer basics and examine ways toapply simple analog techniques to anypersonal computer with a pair of analogjoystick ports.

Why Analog Computers?Since very few users of personal com-

puters are even aware of analog comput-ers, they stand to miss significant oppor-tunities. Creative hardware and softwareusers can benefit by adding to low-costdigital computers some of the operatingtechniques used with analog machines.

That's because some of today's analogmachines incorporate digital logic andeven entire digital computers. Such ma-chines are sometimes called hybridcomputers.

Because the basic principles of theelectronic analog computer were devel-oped as long as 50 years ago, it's onlynatural to wonder what advantages ana-

log machines can possibly have overtheir digital counterparts. One major ad-vantage is the ability of an analog ma-chine to realistically simulate or modelsystems whose performance can only bedescribed by interdependent sets of lin-ear or non-linear differential equationshaving many variables. For example, an-alog computers can easily simulate thelevel and extent of flooding that resultswhen a river's watershed receives anoverabundance of rain. Likewise, analogmachines can simulate the operation,over a wide range of conditions, of air-craft, ships, chemical manufacturingplants, nuclear reactors, and many othersystems.

In all these examples, the analog com-puter can provide real-time solutions tothe problem at hand because the com-puter functions as an electronic modelwhose parameters can be changed as fastas an operator can turn a dial.

For instance, assume you're the oper-ator of an analog computer programmedto simulate the operation of a new sportscar. Dials on the machine's control panelallow you to instantly specify the car'sweight, dimensions and speed. Switchesallow you to select such options as re-tractable headlights and various kinds ofexternal rear-view mirrors.

Though our hypothetical analog com-puter incorporates an analog "front

PATCH O o ens)PANELON 0

((t 0 0 OFF ON

0 Cr0NANALOG COMPUTER

112)SPEED

LEFT RIGHT ROTH ON RETRACTEDZT -1- -L

WEIGHT WIDTH LENGTH MIRROR HEADLIGHTS

CONTROL PANEL

DIGITAL READOUT

Fig. 1. Analog computer sports car simulator.

end," most of its output devices are fa-miliar to users of digital personal com-puters. In addition to a printer they in-clude a cathode-ray tube and an x -y penplotter, both of which represent, graphi-cally, the car's performance. Figure 1summarizes the complete system in ablock diagram.

As you vary the car's design parame-ters, the various output devices almostimmediately display the results. Theprinter lists the fuel efficiency (in milesper gallon) and aerodynamic drag coeffi-cient that result from any combinationof parameters you have selected on thecontrol panel.

Yes, a digital computer can be pro-grammed to provide the same results.One way would be to have the computerstep through every conceivable variationin the car's parameters and provide list-ings and plots of the resulting perfor-mance possibilities. But this methodwould require more operating timeandwould produce far more informationthan you need.

Furthermore, the all -digital approachremoves the human -machine interface,the direct link between operator andcomputer that allows a human being toincorporate creativity, intuition, experi-ence and knowledge in the design of anew sports car. In other words, the ana-log computer gives you all the advan-tages that result when you can casuallychange the parameters of the hypotheti-cal sports car and instantly see theresults.

I hope you're now convinced that ana-log computers have much to offer. Sohow can the owner of a digital computercan get into analog computing.

Fortunately, some basic analog com-puter techniques can be effectively usedwith any digital machine equipped withone or more analog -to -digital convert-ers. In other words, if your computer hasa pair of analog joystick inputs, chancesare you can develop programs that willdigitally simulate the ultimate simula-tor, the analog computer.

In this and next month's column we'llexplore this topic in some detail. Let'sbegin by rediscovering some analogcomputer basics.

24 Computers & Electronics

What's the catch?Yes, there is a catch. Theguaranteed lowest prices inAmerica on hardware and soft-ware for your IBM and Applecomputer are now availableonly to members of The MicroExchangesm. But, the goodnews is it costs only $25 tojoin, and you can earn thatback plus much more!

ComputerizedBiddingThe Micro Exchange- islinked by computer with anationwide network of sup-pliers who are eager to bid onyour order. Through bidding,we're able to purchase productsfor you at prices which areguaranteed to be the lowest inAmerica. Simply call the toll -free number, available tomembers only, with the makesand model numbers of theitems you wish to purchase.We'll handle the transactionand arrange for the delivery ofyour merchandise right to yourdoorstep. All donequickly and effi-ciently so we keepyou as a satisfiedmember of TheMicro Exchangesv.

r

S'8

OURINCREDIBLEGUARANTEE

If you find that any itemyou purchased through

The Micro Exchange wasavailable at the time ofyour purchase at a lowernationally advertised

price, send us appropriateproof of the lower price,including sales tax, ship-ping, and other charges,

within 21 days of your pur-chase, and we will refundthe purchase price and the

merchandise is yours!

Call toll -free today to join...

1SIOCR°IVOOa

A Serviceet RticroY

ision,inc.

1-800-34M-ICRO(In Florida Call: 1-800-35M-ICRO)

Earn More ThanYou SpendYou'll want to tell all yourfriends and associates aboutthe guaranteed savings at TheMicro Exchanges".. And forevery new member you refer,we'll thank you by paying you$10 cash! Not only will youeasily cover the cost of yourmembership, but you can evenearn hundreds of dollars morethrough this unlimited offer.

Hardware, Software,You Name It.We'll furnish you with virtu-ally everything you need foryour IBM and Apple system,including products from theseleading manufacturers: Amdek Apple Ashton-Thte AST BPI Broderbund CDC Digital Research Dow Jones Epson Hayden Mayes IBM IUS Lotus MicroPro Microsoft NEC Peachtree Quadram Rana Software Publishing Tandon Mac lecmar Visicorp

Yes, I want to be guaranteed that I'm purchasing myhardware and software at the absolute lowest pricesin America.

Charge my 7 Visa 7 Master Card Check or Money Order enclosed

Credit Card No. Expiration Date

Name

Address

1MicroVision, Inc.2915 Independent SquareJacksonville, Florida 32202904-634-1020

City State Zip

Telephone (

Signature

In the battle betweenthe IBM PC, there can be

Hear the guns?It's a battle for your desktop. Apple versus IBM'

The easy -to -use Macintosh against the serious businesscomputer from Big Blue.

And the winner? Epson' That's right, Epson. Becausefor the person who simply wants to buy one relativelyperfect personal computer, the Epson offers an opportunityfor peace in our time.

A computer that is easy to use, like the Mac, but alsoruns all sorts of business software, like the PC.

And aren't those two computers exactly the one you need?

An easier way to be easy...A more serious way to be serious.

The Epson is easy becauseits keyboard works in English,not computerese. And only

the Epson comes with Valdocs,' a powerful integratedsoftware system that takes you step-by-step through the fivemost important business functions: word processing,business graphics, telecommunications, electronic filingand daily scheduler.

As a result, while IBM owners are still pondering theirmanuals, and Macintosh owners are still drawing sneakers,Epson owners are churning out productive work withelectronic speed and accuracy.

The Epson also opens the doors of your disk drives- to the largest collection of software in captivity. In fact, the

Epson runs more business programs than the IBM PC?To start, the Epson is available with an optional 16 bit

co -processor so you can use almost any MS" -DOS program,including SuperCalc. 3 and Lotus' 1-2-3'

The Epson also comes with Microsoft' BASIC andCP/M-80' 2.2.

The CP/M library is impressive. It includes themost popular, most powerful businessprograms like WbrdStar' and eiRasPPlus about a thousand other businessprograms, everything from fixed assetaccounting to pipe network analysis.

With MS-DOS, Valdocs and CP/M, the

the Apple Macintosh andonlyone winner. The E son.

Epson should be able to handle any future business need. And that should make you feel verygood about siding with Epson today.

The ultimate technicalspecification: value.

The Epson QX-10 comes completewith a 12" high resolution monitor, 600 x400 Pixels, driven by one of the mostpowerful graphic processors available.With screen resolution this good, textand graphics will leap off the screen.And when you add a graphics pro-gram, like Q -plotter," you canproduce presentation graphics ofthe highest order.

Standard issue on the Epsonalso includes 256K memory, plus128K resident video memory, dual380K Epson -made disk drives, aCMOS Realtime Clock/Calendar withbattery backup, a 1 -year warranty, anRS -232C port and a parallel port; thusfreeing the five- that's right, five-

ilk

option slots for some real options.Best of all, everything is Epson quality,

the same quality that has made Epson thenumber one manufacturer of computerprinters, worldwide. And when you consider

that Epson gives you a complete com-puter system at a price a thousand dol-

lars less than either Apple or IBM,you understand why this computercan not only bring peace to your

ion desktop, but to your budget, as well.

VP prowl IIE-COS board Apple, the Apple lop BA Emit saw 1

4111/ ol Apple Conaweera . Epson Cop. Scam Lotus. Ovalusis 1-24 0,0480, Microsoft NbrdSlar and dean I we wand Indwriarkl

Moos* Maroon and APPIAN, lespectwely Val= fa (1.0ollaVadwfwks Fldno Star Mama and lAefro Software

reps.:Warr

EPSONSTATE -02 -TEE -ART... SIM PLIcrl

Computer Scientist

RI500011

R2500011

Fig. 2. Variable resistor analog addition circuit.

RII oon

10V

DIGITALVOLTMETER

Fig. 3. Variable resistor analog multiplication circuit.

Analog Computer BasicsMechanical analog computing ma-

chines have existed for more than athousand years. One of the most widelyused analog computing machines, theslide rule, was made obsolete only a de-cade ago by the portable scientific calcu-lator, a digital microcomputer contain-ing in its ROM stored programsdedicated to solving specific mathemati-cal problems.

It's well-known that digital computercircuits process electrical signals that oc-cupy one of two discrete levels. A float-ing or disconnected state, the so-calledthird state, may also be present. For ex-ample, when various circuits are con-nected to a common bus, to prevent con-fusion only one can be allowed to place asignal on the bus. The others are effec-tively isolated from the bus by circuitscalled three -state buffers or gates.

Analog computers process signalsover a wide and continually variablevoltage range. It's therefore much easierfor analog computers to represent andperform mathematical operations uponnumbers that have been represented byvoltages.

On the other hand, digital computersare much more precise than analog ma-chines and are therefore essential whenpaychecks, bank balances, loan state-ments, budgets and the like are beingcalculated.

Sometimes, however, the precise re-sults offered by digital computers are su-perfluous. For example, would you pre-fer to read from a digital display thatyour car's fuel tank is 26.2 percent full orglance at an analog gauge that revealsyou have about a quarter of a tankful re-maining? Even if you prefer the digitalreadout, the reading is only as accurateas the analog sensor that measures thelevel of the fuel and the analog -to -digitalcircuit that drives the readout.

On a grander scale, an analog comput-er programmed to simulate a rain -

drenched watershed might predict aflood crest of 15.2 feet with an errorrange of -1-1 percent. A digital computersimulation might give a more preciseprediction of 15.187568439731 feet. Butsince both predictions are subject to thesame input errors (e.g., the uniformityand quantity of rainfall, condition of thesoil, vegetation type and density), bothprovide a figure of about 15.2 feet. Ifyou're not convinced, ask yourself whichvalue the radio announcer will read overthe air to an audience of potential floodvictims.

Analog computersprovide real-time

solutionsto problems

The preceding example also illustratesthe role analog sensors play in manykinds of dedicated (single function) digi-tal computer systems. Though the digi-tal portion of such systems may haveten- or twelve -place accuracy, the accu-racy of the analog sensor is considerablyless, probably no more than a few tenthsof a percent. Moreover, the overall re-sponse of an individual sensor may notbe uniform with other sensors.

All in all, miniature analog computersmight well be at least as effective as theirdigital counterparts in dedicated appli-cations involving analog sensors. Thenwhy aren't they as popular?

In my opinion, a principal reason isthat analog circuit design is fast becom-ing a lost art. Another reason is that themicroprocessor arrived before sophisti-cated single -chip analog computer chips.This technology gap provides some in-teresting opportunities for creative com-

puter enthusiasts, and I'll have more tosay about it in Part 2 of this two-partcolumn.

Do-lt-Yourself Analog ComputersWhile large-scale analog computers

can be very complex, small-scale ma-chines can be surprisingly simple. Forexample, though practical analog com-puters are designed around precision op-erational amplifier circuits, simple ana-log computers can be constructed from afew potentiometers and a multimeter.

Figure 2 shows an analog adding ma-chine. This ultra -simple circuit requiresonly two inexpensive potentiometersequipped with pointer knobs and scales.The circuit can display its results on aconventional analog meter or a digitalmultimeter.

If each potentiometer has a resistanceof 5,000 ohms and if each ohm repre-sents a unit, then this analog adder cansum any two numbers of up to 5,000 andprovide a total of up to 10,000. Simplyby changing the potentiometer scales, aform of programming, the machine canbe set to add virtually any pair of num-bers provided that an appropriate cor-rection factor is applied to the value dis-played by the multimeter.

Figure 3 shows how the two potenti-ometers in Fig. 2 can be rearranged or re-programmed to provide an analog multi-plication machine. Here the potentio-meters are connected as voltage dividersacross a 10 -volt power supply.

How does the multipler work? Ignor-ing the value of the potentiometers, as-sume each is equipped with a scale hav-ing eleven equally spaced lines. The scalefor RI is marked 0 through 10 while thatof R2 is marked 0 through 1 in incre-ments of 0.1.

When RI's pointer is rotated to the 5position on its scale, its wiper is at itscenter position and the voltage appear-ing across the wiper and ground is halfthe input value, or 5 volts. Likewise,

28 Computers & Electronics

The Heathkit Catalog& American Technology...Inseparable!

fled f IT& it

Ever since radio grew into electronics, the illustratedHeathkit Catalog has been a guide to new and exciting elec-tronic kit products for people like you to build Enjoy. Learnfrom. And save money.

The Heathkit Catalog is now even better. The ALL NEWfull -color catalog features more than 450 different products inelectronics, computers and other state -of -art technology. Pageafter page is devoted to new and exciting products for yourhome, hobby and business.

If you don't have the latest Heathkit Catalog. you're missingsomething great! Now's your chance to get involved inAmerican Technology first hand. Your free ALL NEW HeathkitCatalog is waiting for you.

Fill out and return the attached Catalogrequest card today! Or use reader service

number below.Circle No 24 on Free Information Can't

Great innovations in electronics are at your fin-gertips in each quarterly issue of the HeathkitCatalog. From computers to test instruments tothe latest in personal robotics. Act now and sendthis card for the ALL NEW Heathkit Catalog.

CATALOG OFFERHeath CompanyDept. 010-219Benton Harbor, MI 49022Yes I want to see tie latest in electronics from Heathkit.Please send my free copy of the ALL NEW HeathkitCatalog to:

Name

Address

City

StatePC -148

DiscoverthePride

With Heathkit, you'll discover the pride of accom-plishment only a hand -built quality product canprovide. From Stereos and TVs to Ham Gear andthe latest in education. Act now and send thiscard for the ALL NEW Heathkit Catalog.

CATALOG OFFERHeath CompanyDept. 010-219Benton Harbor, MI 49022Yes I want to see the latest in electronics from Heathkit.Please send my free copy of the ALL NEW HeathkitCatalog to:

Name

Address

City

State ZipPC -148

CV

0cs)

ct 0, 0E ( "Jo

C.) c_c 076 cI o c0

0CY)

CZ 0) 0

EO 0 I0 c) c_c 00 0 0

a co

Kitbuilding is aexciting hobbyand unique learn-ing experience forthe whole family.

Be a part of today'sciting world of high

technology.

rThe best in electronics

is hand -built by you.Building advanced

computers and electronicproducs from kits is a

great hands-on way todevelop skil s and ability in

many technologies. Easystep-by-step directions

take you through the build-ing process. And we backour products and you with

the simple promise: Wewon't let you Heathkit

builders create more than fineproducts. They build pride.

OVER 450 KITS TO BUILD Computer hardware and

software Robcts Self -studycourses in electronics Preci-

sion test instruments Comput-erized weather instruments lar hot water systems Auto-

motive and home energyprod acts Security

devices :olor TVs andvideo accessories

Quality Stereo compo-nents Amateur

radio gear

Start by ordering your FREE4 Heathkit Catalog today. Or use

Reader Service NumberCircle No. 24 on Free Information Card.

eh.

Computer Scientist

when R2's pointer is rotated to the 0.5position on its scale, its wiper is also at itscenter position, and the voltage acrossthe wiper and ground is half the inputvalue, or 2.5 volts. This output voltage isthe product of the two potentiometersettings (5 X 0.5 = 2.5).

The simple addition and multiplica-

this circuit is the product of the feedbackresistance (R2) and the input voltage(V1) divided by the input resistance(RI). Therefore, the basic circuit in Fig.4 can perform multiplication anddivision.

Figure 5 shows how the circuit in Fig.4 can be slightly modified to enable it to

VOLTAGEIN

(VIN)

VOLTAGEOUT

(VOUT)

R2 X VINVOUT RI

Fig. 4. Basic operational ampSfier variable resistor multiplier.

tion circuits in Figs. 2 and 3 can be mademore accurate by using multi -turn preci-sion potentiometers. Ten -turn dial po-tentiometers are an excellent, albeitrather expensive, choice.

Moreover, both the addition and multtiplication circuits can be combined intoa single circuit that can be reconfiguredby means of a patch panel equipped withswitches or removable plugs and wires.By doing so, a programmable analogcomputer can be created.

Experienced circuit designers can re-place the requisite programming wires,plugs and switches with analog gates. Adigital word (i.e., binary number) muchlike a digital computer's machine lan-guage instruction, can then be used totell the computer to add or multiply. Theanalog computer can be greatly expand-ed using such techniques. And it can becontrolled using familiar but, by com-parison, more easily programmed digitalcomputer techniques.

Activating the Analog ComputerThe basic variable resistor analog

computer discussed thus far is a passivedevice. Far more versatile performancecan be had by adding active electroniccircuits, the most important being theoperational amplifier. First developed byGeorge H. Philbrick in the mid -1930sfor use in an early all -electronic analogcomputer, the op -amp, as it is usuallycalled, uses feedback from its output toone of its two inputs to control preciselyits amplification factor or gain.

Figure 4 shows a very basic op -ampfunction block. The output voltage of

perform addition and subtraction. Morethan two voltages can be combined byadding additional input resistors to theadder (summer) circuit.

The summer in Fig. 5 can average thesum of two or more input voltages bymaking the ratio R2/R1 equal to thenumber of input voltages. For instance,if each of two input resistors [R1(a) andRI(b)] has a resistance of 100,000 ohms,

ship between the voltage drop across apn junction and the current flowingthrough the junction makes possible thisimportant analog computer functionblock.

Op -amps can provide many otherfunctions useful in analog computers, in-cluding integration, differentiation, rais-ing exponents and function generation.

As you can see, the op -amp is to ana-log computers what the logic gate is todigital computers. Op -amps, however,are much more temperamental than log-ic gates. Sensitive to temperaturechanges, high -accuracy op -amp func-tion blocks require precision resistorshaving a tolerance of 0.1 percent.

These drawbacks are a major reasonwhy analog computers were soon sur-passed by more dependable and predict-able digital computers. In recent years,however. analog computer functionmodules have been fabricated with on -chip resistors having unprecedented ac-curacies. One such circuit, the AnalogDevices AD534, includes a dozen on -chip resistors trimmed to a high degreeof accuracy by a pulsed laser.

When first introduced five years ago,its manufacturer called the AD534 thefirst single -chip analog computer. Sincethis chip can multiply, divide or squaretwo input voltages or take the squareroot of a single input voltage-all withan accuracy of ± 0.25 percent-theAD534 certainly qualifies as a powerful

Fig. S. Basic operational ampkter variable resistor multiplier.

R1(a)100K

VIN R1(b)100K

R2100K

VOUT VIN{

R333K -V

VOUT ( I ) V1N (2)]

ANALOG ADDER (SUMMER)

then changing R2's resistance to 50,000ohms will cause the output voltage toequal the average of the two inputvoltages.

More precise multiplication, divisionand square root extraction can be per-formed by means of an op -amp operatedas a logarithmic amplifier. This is ac-complished by substituting a diode ortransistor in the feedback loop of an op -amp. The natural logarithmic relation-

RI(a)100K

Rl(b)100K

R3100K

R2100K

VOUT

-VVOUT -VIN= (2)-VIN1

ANALOG SUBTRACTOR

analog processing chip. I'll have more tosay about it and similar chips in Part 2.

Simulating an Analog Computerwith BASIC

If you enjoy experimenting with hard-ware, you can assemble a surprisinglypowerful analog computer from a fewop -amps, an AD534, a patch panel and adigital multimeter. Alternatively, you

(Continued on page 113)

I)

September1984 31

WHEN HEWLETT-PACKARDDEVELOPED A PERSONAL COMPUTER

PRINTER THAT USES A QUIET JET OF INK,PRINTS150 CHARACTERS PER SECOND

AND COSTS ONLY $495,

THE WORD TRAVELED FAST. .

UtKIFTT-;

611111111111111111111111111111111166111111101.116.

THINKJET.Hewlett-Packard research has used inkjet

technology to make the ThinkJet personal com-puter printer surprisingly quiet while printing150 high quality, dot-matrix characters per secondfor text or graphics. The ThinkJet printer weighsonly 61/2 pounds and it takes up just a bit moreroom than your telephone. So, it can work right onyour desk. There's even a battery -powered modelthat lets you print anywhere. And, the ThinkJetprinter's ink supply and printhead are designedm one neat disposable unit that simply dicksout when it's time to change.

The ThinkJet printer will work with mostpopular personal computers, including Hewlett-Packard, IBM? COMPAQ' TI? or Apple Ile?

Finally, as quiet, fast and compact as theThinkJet printer is, it still has one more featurethat's going to cause a commotion; its price...$495.00?

See the entire family of personal computers,software and peripherals at your authorizedHewlett-Packard dealer.

Call (800) FOR-HPPC for the dealernearest you.

Setting You Free

paHEWLETTrAIPACKARDIBM is a registered trademark of International Business Machines Corporation. LUNI 'AO is a trademark of COMPAQ Computer Corporation.TI is a registered trademark of Texas Instruments, Inc. APPLE is a registered trademark of Apple Computer, Inc. 'Suggested retail price.

WHEN HEWLETT-PACKARD USEDLASER TECHNOLOGY10 BRING YOUR

PERSONAL COMPUTER A LETTER QUALITYPRINTER THAT OPERATES AT UP TO

300 CHARACTERS PER SECOND,1

NM=

raHEWLETTP PACKARD

O

THE WORDTRAVELED

TWICE AS FAST."011111.11111.".""00001"..."-,*-.

LASERJET.Now you can print an entire page of text

in just 71/2 seconds. That's the equivalent of 300characters per second. The LaserJet personalcomputer printer can do it. Hewlett-Packard hasbrought the speed, quiet and letter quality oflaser printing to the personal computer user forunder $3,500?

The LaserJet printer is designed for Hewlett-Packard personal computers, the IBM® PC, PC

2091

compatibles and most other personal computers.No other personal computer printer is

engineered to do what the LaserJet printer cando at such an affordable price. But then considerwhere it came from.

See the entire family of personal computers,software and peripherals at your authorizedHewlett-Packard dealer. Call (800) FOR-HPPCfor the dealer nearest you.

Setting You Free

paHEWLETTEAPACKARDIBM is a registered trademark of International Business Machines Corporation. 'Suggested retail price.

HARDWARE REVIEWS

EPSON PX-8LAPSIZECOMPUTERA 5 -pound portable thatsports ROM -basedWordStar, BASIC, andspreadsheet software

BY JOSEPH DESPOSITO

Although several lapsize comput-ers sell for under $1000, all suf-fer from a lack of software.

Now, however, Epson has produced alapsize computer, the PX-8, which usesthe CP/M operating system-thus it canaccess one of the largest software basesavailable for micros. For software start-ers, the PX-8 comes standard with Por-table WordStar, Calc and Scheduler inROM capsules.

The size and layout of the PX-8 arereminiscent of Epson's HX-20 (the firstlapsize computer), with some significantdifferences. Gone, naturally, is the 4 -lineby 20 -character display; it is replaced byan 8 -line by 80 -character LCD that flipsup for use. The microcassette tape drivein the HX-20 is also present in the PX-8.

Missing, however, is the microprinter.Suggested retail price of the PX-8 is$995.

A bevy of optional peripherals is avail-able to enhance the standard PX-8.Chief among them are a 3 `/2" disk driveand a 120K RAM disk, which sell for$599 and $460, respectively.

General Features of the PX-8The PX-8 is a 5 -lb bundle. With di-

mensions of 11.7"W x 8.5"D x 1.9" H,it is almost identical in size to its prede-cessor. For traveling, a molded plasticcover fits over the keyboard, the LCDfolds down flat over the microcassetterecorder and speaker, and a plastic han-dle slides out from the front of the case.In use, the handle retracts, the covercomes off, and the display tilts up to anappropriate viewing angle. Two legs atthe back of the unit can swing down toadjust the angle of the keyboard.

On the rear panel of the computer aretwo 8 -pin miniature DIN plugs, whichare the serial (printer) and RS -232C(modem) ports. Three phono jacks areused for the speaker output, an analog/

digital (A/D) input, and barcode readerport. A recessed reset switch lies alongthe left side of the unit, while the powerswitch is along the right. The latter is un-der software control, which means thatthe machine can be programmed, in con-junction with a built-in clock, to turn onand off automatically.

Rechargeable nickel -cadmium batter-ies are housed in a compartment on theunderside of the computer. There aretwo batteries, main and backup. Themain battery runs for about 15 hours, de-pending on I/O operations. When itneeds recharging, the backup batteryprotects the contents of memory. Anadapter that plugs into the back of theunit is used to recharge the batteries,which takes about 8 hours.

Another compartment on the under-side gives the user access to the comput-er's removable ROMs and an 8 -pin DIPswitch. The switch is used to customizethe keyboard for any of seven differentlanguages.

Inside the MachineThe PX-8 has three microprocessors.

*me MENU screen 03/01/84 (WED)C: PIPC:PIP COM C:STAT COMC:FILINK COM C: TERM COM

P4:26:07 54.5k CP/M ver 2.2 PAGE I/1

C:SUBMIT COMC:CONFIG COM

C:XSUBB: BASIC

COPCON

Fig. L Startup menu screen shows the CP/M ROMas the C drive and the BASIC ROM as the B drive.

PHOTOS BY MICHEL TCHEREVKOFF34 Computers & Electronics

TABLE I-PX-8 OPERATING SYSTEM MODULES

The operating system of the PX-8is functionally divided into sever-al units which are referred to as

modules. Some of them are part of theCP/M operating system and others sup-plement it.

System Display module. Enables themicrocassette tape to be operated man-ually and also to check and reset some ofthe system parameters.

Password module. Makes it possible tostop unauthorized users from using thePX-8 without knowing an entrypassword.

MENU module. Displays programfiles and data files on the screen andmakes it easier for the user to run any

program file by selecting it on the screen,using the cursor keys rather than havingit to type the full name.

Screen dump module. Used to make acopy of the current screen on a printer.

Console Command Processor (CCP).This is the part of the CP/M operatingsystem which interprets commandstrings typed on the keyboard. Thismodule includes the CP/M buit-in com-mands (Dir, Type, Ren, Era, Save andUser).

Basic Disk Operating System(BDOS). This is the part of the CP/Mwhich manages disk files. It also treatsthe ROM capsule and RAM as diskdevices.

Microcassette Tape Operating System(MTOS). Manages microcassette files.

Basic Input/Output System (BIOS).This part of the CP/M acts as the inter-face between the operating system andinput/output devices, e.g., the screen,keyboard and RS232 interface.

Microcassette Input/Output SystemMIOS). I/O interface between MTOS

and microcassette firmware.

Clock module. Controls alarm andwake functions and updates timedisplays.

System activator. Controls system ac-tivation, deactivation, the auto -startfunction and initialization.

The main processor is a Z -80 -compatibleCMOS CPU. Additionally, a 6301 pro-cessor is used for display and input/out-put control, and a 7508 processor con-trols interfacing with the keyboard andthe A/D converter. A block diagram ofthe system configuration is shown onpage 38.

Standard memory of the PX-8 is 64KRAM and 32K ROM, controlled by theZ-80. 6K of video RAM and 4K ROMare controlled by the 6301.

The ROMs, as mentioned, are accessi-ble to the user. In the old HX-20 userswere warned against inserting CMOSROMs themselves, owing to the sensitiv-ity of CMOS chips to damage by staticelectricity. In the PX-8, however, Epsonhas devised a package (not an enclosedROM cartridge, as in other computers) inwhich the ROM chip is seated, but ex-posed. With careful handling, the usercan insert and remove the ROMs, whichmay contain the CP/M operating system,BASIC. Portable WordStar, Portable

Battery -powered 31/2" drive.

Calc, or other programs. Removing oneROM capsule and slipping in another isfairly straightforward though not nearlyas easy as using a ROM cartridge. UnderCP/M, each ROM is identified as a "diskdrive." ROM 1 is seen as the B drive andROM 2 as the C drive in the standardconfiguration, but they may be changedthrough the CP/M CONFIG program.

Access to the system bus is availablethrough a connector on the back panel.It's through this bus that optional pe-ripherals, such as the RAM disk, can beconnected.

The DisplayThe PX-8 uses a liquid -crystal display

for video output. It displays 8 lines of 80characters each in the text mode and hasa resolution of 480 x 64 dots in thegraphics mode. The hinged display tiltsup for viewing to a variety of angles. For"fine tuning" the display, there is a"view angle" slide adjustment just belowthe screen.

The display dimensions are approxi-mately II/2" x 9". Alphanumeric charac-ters stand about 1/2" high, which canmake for some difficult viewing sincecharacters are constructed with singlerows of dots (the normal method). Otherlap -size computers deal with the prob-lem either by displaying larger charac-ters or by using a more elaborate (andreadable) character set. One other defi-ciency of the character set is that lowercase characters such asp, j, g do not havetrue descenders.

An additional difficulty with the dis-

RAM disk attached to the PX-8.

play is that the retrace lines are visibleunder flourescent lighting, although un-der incandescent lighting they are not.

To conserve power, the screen displayautomatically switches off if there hasbeen no keyboard input for 10 minutesor for an interval, between 1 and 255minutes, the user sets.

The KeyboardOne of the most noticeable improve-

ments of the PX-8 over the HX-20 is thefeel of the keyboard. The keys are firm tothe touch and excellent for typing. Thereare 63 alphanumeric and special keys.There is also a row of nine one-third sizekeys. Five of them are function keys, andfour are designated STOP, ESC, PAUSEand HELP.

The standard keys are color coded-dark grey (alphanumerics), light gray(special keys), red (return), and orange(four separate cursor keys)-which en -

35

DisketteUsers...When you'veheard fromall theanimals inthe diskettezoo, but youneed fastdelivery andhigh qualitydiskettes...

Call Communications ElectronicsDiskette order desk

800 -USA -DISKIn Canada 800-CA1-DISK

Choose your brand

Choose your priceProduct Description

8" SSSD IBM Compatible 1 28B/S, 26 Sector8" SSSD Shugart Compatible. 32 Hard Sector8" SSDD IBM Compatible (128 B/S, 26 Sectors)8" DSDD Soft Sector (Unformated)8" DSDD Soft Sector (256 B/S, 26 Sectors)8" DSDD Soft Sector (512 B/S, 15 Sectors)8" DSDD Soft Sector (1024 B/S, 8 Sectors)51/4" SSSD Soft Sector w/Hub Ring51/4" SSSD Same as above but bulk product51/4" SSSD 10 Hard Sector w/Hub Ring51/4" SSDD Soft Sector w/Hub Ring51/4" SSDD Same as above, but bulk product51/4" SSDD Soft Sector Flippy (use both sides)51/4" SSDD 10 Hard Sector w/Hub Ring51/4" DSDD Soft Sector w/Hub Ring51/4" DSDD Same as above, but bulk product51/4" DSDD 10 Hard Sector w/Hub Ring

DSDD 16 Hard Sector w/Hub Ring51/4" DSDD Soft Sector w/Hub Ring (96 TPI)31/2" SSDD Soft Sector micro -floppy

STR_R!r

rsx-/y,47

Super Diskdiskettes tn..$0.94 each

DISKETTES

Wabash

diskettes tu.$0.99 each

I BASF \\

BASF

diskettes$1.44 each

It*.efe

3Mdiskettes$1.44 each

bow 01stPin *

CE quill100 odapit illsk IC

SPort #

CE gout100 oda

oft disk (91BASF

Part *

CE omit.100 Ma

per disk IS)3M

Port #

CE gout100 pile

our disk IC

FIII-P 1.59 13SSSD-P 1.94

F3I A -P 1.79

Fl 3I -P 1.89 83300-P 2.39

F140 -P 2.09 80500-P 289

F144 -I 2.09

Fl 45-P 2.09

Fl 41-P 2.09 00800-1024-P 2.89

5431-P 114 MI1A-P 1.19

5437-P 094 0.99

1141A-/ 1.19--5401-P 1.29 III3A-P 1.34 54074-P 1 44 52800-RH-P 1 64

134111-P 1 09 111301-P 1.14 53300-IIL-P 1 44

1110A -P 1.99

1143A -P 134

5451-P 1 54 1111411-P 1 59 54510-P 179 50200-1111-1 219

54111-1 1 34 111405-P 1.39

11440-P 1.59

1150-P 1.59

550I -P 244 1415A -P 2.49 54992-P 2.99 50800-051111-P 309

54112-P 2 74 333110-P 3 74

For more informationabout this brand call: 800 -USA -DISK

Is Illcblias 313-973-1111

E year warranty Lifetim warrantyFir wen Ile et II call Fir elm Isle is IA$F till

800-323-9868 800-343-4600Is II6aia 312-503-8383 It Namcbotatti 817-271-4000

Lifetim warrantyFir min talc"3N can

800-328-9438I. NI 00000 012-73131524

CE...your best source for diskettesFor you the diskette buyer, it's a jungle out there. There areso many different brands to choose from, you need to go ona safari to find a good brand at a reasonable cost.Fortunately, CE has already hunted for the best diskettesand offers you an excellent choice at a CE price. To saveyou even more, CE also offers bulk product where 100diskettes are packed in the same box without envelopes orlabels. Since we save packaging costs, these savings arepassed on to you. Diskette envelopes are also availablefrom CE. These super strong and tear resistant Tyveleenvelopes are only $15.00 per 100 pack. Use order # TE-5for a 100 pack of 51/4" diskette envelopes.

Quantity Discounts AvailableOur diskettes are packed 10 disks to a carton and 5 or 10cartons to a case. The economy bulk pack is packaged 100disks to a case without envelopes or labels. Please order onlyin increments of 100 units for quantity 100 pricing. With theexception of bulk pack, we are also willing to accommodateyour smaller orders. Quantities less than 100 units are availablein increments of 10 units at a 20% surcharge above our 100unit price. Quantity discounts are also available. Order 300or more disks at the same time and deduct 1%; 500 or moresaves you 2%; 1,000 or more saves 3%; 2,000 or more saves4%; 5,000 or more saves 5%; 10,000 or more saves 6%;50,000 or more saves 7%, 100,000 or more saves 8%,500,000 or more saves 9% and 1,000,000 or more disks earnsyou a 10% discount off our super low quantity 100 price.Almost all our diskettes are immediately available from CE.Our efficient warehouse facilities are equipped to help us getyou the quality product you need, when you need it. If you needfurther assistance to find the flexible diskette that's right foryou, call the appropriate manufacturers compatibility hotlinetelephone number listed at the bottom of this ad. Dealerinquiries invited.

Verbatimdiskettes ms$1.59 each

Memorexdiskettes :A$1.59 each

......,

liM3d)

Ultradiskettes$1.59 each

VerbatimPort #

CE quid100 price

pr Ibt (SIMessrs:Put SS

CE 'list100 priespr list PI

UltraPart *

CE met100 pries

pr disk III

3112-I 1.94 11721-P 1.94

3111-P 1.94

3111-P 2.39

3102-P 2.89 12711-P 2.89

2.893104-P 2.89 62766-1

28820-P 1 59 3411.1 1.59 6111I -P 1.59

12412-P 1.99

28821-P 2 54 3401-P 2.19 62111-P 2.19

28823-P 3 39 3501-P 2.99 12101-P 2.99

6100-1 3.74

Buy your diskettes from CE with confidenceTo get the fastest delivery of your diskettes, phone your order directly toour order desk and charge it to your credit card. Written purchase ordersare accepted from approved government agencies and most well ratedfirms at a 10% surcharge for net 10 billing. For maximum savings, yourorder should be prepaid. All sales are subject to availability, accept-ance and verification. All sales are final. All prices are in U.S. dollars.Prices, terms and specifications are subject to change without notice.Out of stock items will be be placed on backorder or substituted forequivalent product at no extra cost to you unless CE is instructeddifferently. A $5.00 additional handling fee will be charged for all orderswith a merchandise total under $50.00. All shipments are F.O.B. CEwarehouse in Ann Arbor, Michigan. COD terms are available, in U.S.UPS areas for $5.00 extra, and are payable with cash or certified check.

For shipping charges add $8.00 per 100 diskettes and/or anyfraction of 100 8 -inch diskettes, cr $6.00 per 100 diskettes and/or anyfraction of 100 51/4 -inch or 31/2 -inch diskettes for U.P.S. ground shippingand handling in the continental U.S. UPS 2nd day air rates are threetimes continental U.S. rates. For Canada, Puerto Rico, Hawaii, Alaska,or APO/FPO delivery, shipping is three times the continental U.S. rate.

Mall orders to: Communications Electronics, Box 1045,Ann Arbor, Michigan 48106 L.S.A. If you have a Visa or MasterCard, you may call and place a credit card order. Order toll -freein the U.S. Dial 800 -USA -DISK In Canada, order toll -free bycalling 800-CA1-DISK If you are outside the U.S. or in Michigandial 313-973-8888. WUI telex anytime 671-0155. Order today.Copyright O 1984 Communications Electronics Inc.

Circle No. 19 on Free Information Cardry

COMMUNICATIONSELECTRON ICS"

Computer Products DivisionBox 1045 Ann Arbor, Michigan 48106-1045 U.S.A.Call toll -free 800 -USA -DISK or outside U.S.A. 313-973-8888

WOK

'Tails am

TDKdiskettes IL:$1.59 each

Fujidiskettes tr.$1.59 each

Ad *080284

DYNODiskette

Dysan

diskettes v.$1.94 each

TDKPort *

CE mot100 pries

pr list (SIFsp

Part *

CE gust100 pries

sir disk 181Imo

Port *

CE lust100 pries

pr list MI

Fl -E -P 2 34 FOIE -1281-P 1.94 100501-1 2.49---100805-P 2.69

F20 -11-P 289 F020 -P 2.89 110103-P 3 14

F20-81024-1 2.89 F11211 -1024-P 2.89 100138-P 3.14

1 59 1010-P 1.59 101117-P 1.941 -S -P

2.19 11020-1 219 102060-P 2.641121-1-1

111120 -981P1 -P 3992.99 2.99 102067-P

NF10-/ 2.99

Lifetime warranty 8 year warrantyFir men iels a Verbatim all Fe ems Mb a lawn al

800-538-8589 800-448-1422le Caliente 400-245-4400 Na1.rFrwq Ise-Ipm ET

Lifetime warrantyFe we Ile ea VIM all

408-728-7777Illasisy-FrIday 1 so -4 pm PT

Lifetime warrantyFe ma it, a TU

Lifetime warranty Lifetime warrantyFie on Isle es Fell ail Fe ma lie se Ilse al

800-645-6571 800-223-6535 800-552-2211Is In Vert 518-125-0110 la In Yet 012-7311-3335 b CriNsalm 411-171-6118

E^I

Epson PX-8Portable Computer

1 square = 1 inch 04Premenmawst

H Ex 1

0O 0 0 0 0 0 0 0111111111IUMMIM1111111EMMIIIMMEME

hances the aesthetic appeal of the com-puter. Key markings are in white.

There is a type -ahead buffer and mostkeys have an auto -repeat feature. Thekeyboard also has a number of other so-phisticated features. For example, if youpress NUM/GRAPH and an alphabetic keysimultaneously, a graphic such as a min-iature telephone or airplane is displayedon the screen. Also, pressing Num/GRAPH and the shift key sets up a blockof keys as a numeric keypad. Thoughthere are just five function keys, pressingshift in conjunction with the keys givesyou five more. You can program all"ten" function keys.

Mass StorageThe primary storage device for the

PX-8 is a built-in microcassette record-er. The tape it uses holds 10K -50K bytesof data per side (maximum number offiles is 12). The recorder can be con-trolled manually or with software.

RAM disk storage is also available onthe standard unit. You can set aside aportion of memory for data and pro-grams as large as 24K.

For users who need more storage,Epson manufactures a 31/2" disk driveand 60K and 120K RAM disks. Thedisk drive plugs into the serial port at theback of the unit and provides its own se-rial port for a printer or second drive.Thus, the peripherals are connected in"daisy chain" fashion to the computer.The drive, which is battery operated,was designed by Epson to be compatiblewith 3'/2" Sony (or similar) micro -floppies. It uses double -sided, double -density disks that have a capacity of360K bytes. Dimensions of the drive are4.7"W x 8.4"D x 2.3" H; weight is 3.3 lb.

The RAM disk attaches directly tothe underside of the computer and tilts itabout 15 degrees. It has a write -protectswitch that's used to disable the write

function, if desired. (In other words, youmay read from the disk but not write toit.) In addition to the 60K and 120KRAM disks, Epson also sells a Multiunitfor $360, which combines a 60K RAMdisk and direct -connect modem. (Asseparate products, the 60K RAM diskcosts $329, while the direct -connectmodem costs $180.)

Operating System and LanguageThe PX-8 uses an extended version of

the CP/M 2.2 operating system, whichexists in a ROM capsule. The menuscreen shown in Fig. 1 appears uponstartup. As you can see from the figure,the CP/M ROM is designated as the Cdrive. You can access the files shownsimply by moving the cursor to the nameand pressing return. Or, a more tradi-tional option lets users modify the sys-tem through the System Display pro-gram so that the prompt C > is

(Continued on page 92)

Block diagram of the system configuration of the PX-8.

r ROM32K

Z-80Main CPU

RAM64K

- -1RAM disk

unit

L

6301Slave CPU

RS232interface

FBar codereader

interface

1SK for -Nine,VRAMI

ROM4K

7508Slave CPU Clock

Power -Isupply

rSerial

speakerinterface

LCD

allicrocassetdrive

ROM

1CeP.UI

Printer

Acousticcoupler

Bar codereader

Floppy deskunit

TSpeaki;1

Keyboard

Analoginterface

Printer]

Externalspeaker

Floppy diskunit

38 Computers & Electronics

ELECTIVE:1M BOOK CLUEThe Best Source for Hobbyists and Professionals

for Over 18 Years!

Time- and Money -Saving Advice . . .

Practical Troubleshooting & Repair Tips . . .

State-of-the-art Technology . . . Hundredsof Projects . . . Plus, Exceptional Savings

Select 5 Booksfor Only X295

READINGSCHEMATICS

PERSONALCOMPUTERS

1539List $19.95

111,11,11,

CELLULARCOMMUNICATIONS

MOW 'titre my

1682List $14.95

1665List 521 95

1160 1531 800List 514.95 List $17 95 List $18.95 (paper)

114ndb"Oo11001P.t.I [Intro.. ['root,

77.77;:inr.

1532 c 1507List $10.95 (paper) List $15.95

1585List $21.95

1337List 510.95

Ready -To -RunPrograms inBASIC

s looms..6,1.04

1195List $13.95

H111011'1011111FIRTH STAT1111FOR WORLDWIDESITMITF TI

'409List $15.95

List $24.95

1671List $21.95

I MILRST 4 %MM.

ELECTROVCS..

1211 1.532 1306 1553List 516.95 List $16.95 List $9.95 (paper) List $15.95

FREE When You Join Now7 very good reasons to jointhe Electronics Book ClubBig Savings. Save 20(7( to 75" on books sure to increase

your electronics know-how No -Risk Guarantee. All books returnable within 10 dayswithout obligation Club News Bulletins. All about current selections-mains,alternates, extras-plus bonus offers. Comes 13 times a yearwith hundreds of up-to-the-minute titles you can pick from "Automatic Order." Do nothing, and the Main selection willbe shipped automatically! But . . . if you want an Alternateselection-or no books at all-we'll follow the instructions yougive on the reply form provided with every News Bulletin Bonus Books. Immediately get a Dividend Certificate withevery book purchased and qualify for big discounts of 607r to80c7,

Extra Bonuses. Take advantage of added -value promo-tions, plus special discounts on software, games. and more

Exceptional Quality. All books are first-rate publisher's edi-tions selected by our Editorial Board and filled with useful.up-to-the-minute information

September1984 Circle No.

1419List $19.95

VIDEOELECTRONICSTECHNOLOGY!

tT

1474List 516 95

C111111111

REMO" MCINNISWITH EIFFRINERTS

1557Ust $14.95

MUM

comma1199

List $19.95 1537List 516.95

Noir TO

TROUBLESHOOT ffPAIR

ELECTRONIC ColcuiTS

J.1218

List $18.95

III IIIs CMOS TTL I

A Users Gale.with Prefects

\List 65509 95

EXPLIIII5S Flit !InnLLFITIIMICS

1.1.111

1497List $15.95

/41 YOUT

TELEPHONES

FREE guide tomail order sourcesfor electronic partsand componentsA $6.95Value!

.......ELECTFUNICS BOOK CLUB

I P.O. Box 10I Blue Ridge Summit, PA 17214

Please accept my membership in the Electronics Book Club and send the 5 volumesCircled below, plus, my FREE copy of The Electronics Buyer's Guide, billing me $2.95plus shipping and handlirg charges. If not satisfied, I may return the books within tennays without obligation and have my membership canceled. I agree to purchase 3 ormore books at reduced Club prices (plus shipping/handling) during the next 12months. and may resign any time thereafter.

800 1160 1195 1199 1211 1218 1306 1337 1409

1419 1474 1497 1507 1531 1532 1536 1537 1539 1541

1553 1557 1585 1604 1632 1650 1665 1671 1682

Name

Address

Phone

IcyI Sate Zip

Valid for new members only Foreign applicants will recer,e special ordering instructions. CanadaImast remit in U S currency. This order subtect to acceptance by the Electronics Book Club

SIN INN I= EN =I EN OM INN 11=1 INNI INN = =I NM M MN MO NO INN I= NW MNCE -984

39 on Free Information Card 41

LW0 0 0 a 0 al 0 =====0 at aa a 0 CP Oa CO 0 AMP Or0, 0 NV A, 4,0 OM MO II

STEARNS

DESKTOP

COMPUTERA fast 8086 -based MS-DOS machine offeringspecial function keys,other advanced features

BY BILL BARRETT

SOME computer manufacturersforego technical improvementsfor compatibility; others stress

technical superiority over compatibility.In either case a buyer should know thetradeoffs. In its computers, Stearns em-phasizes technical developments, suchas special function keys, for more flexi-bility and ease of operation.

While Stearns does sell a computerwith two 51/4" floppy drives, 128KRAM (expandable to 896K), and a 12"black and white monitor for a suggestedretail price of $2995, we tested the XTversion. A more elaborate configuration,it has 384K RAM, a 10 Mb hard disk,and a double -sided 51/4" floppy drive.Comparable to the IBM PC -XT, it sells

for $6195. (No applications software orlanguages are included in the price.)

Stearns offers some rare options, forexample, a monochrome monitor withan eggshell phosphor and a monitor forword processing that can display 54 80 -character lines (similar to a standardsheet of paper).

Other hardware available fromStearns includes an external hard diskdrive that can add 10 or 20 Mb of diskstorage and a streaming tape backupunit capable of archiving a 20 -Mb disk inless than 10 minutes.

Stearns has also aimed for ease of op-eration with its software products. Theunit we tested included such popularpackages as Lotus 1-2-3 and Wordstarenhanced with up to 40 "soft" functionkey commands. The result is a signifi-cant reduction in the time it takes tolearn and use these programs.

The Stearns LookThe Stearns XT comes in the usual

three pieces: keyboard, monitor andmain processing unit. The processorcabinet measures 5'/2" by 151/2" by 22",about 3" wider than the IBM PC. Owingto its sleekness, however, the Stearnsunit looks smaller than the IBM. On thefront panel are half -height disk drives.On the rear apron are connectors for avideo monitor and two serial ports andthe exit port for forced air circulation.

The Imre&Under the hood of the main process-

aea'V.41' Yin

. rl 11 uni canon 0 vsannonmonsa

101111a11111111M1111111111OUNIM7

ing unit is an 8 -MHz 8086 CPU. Notonly does the 8086 have a clock speedfaster than the 4.7 MHz of the IBM PC's8088; it also is a true 16 -bit unit. A sock-et is available for an 8087 mathcoprocessor.

The Stearns unit is powered by an air-cooled switching power supply similar insize but larger in capacity than othercomputers in its class. A Shugart SA455floppy and Miniscribe hard disk handlethe mass storage chores. The floppydrive is dual -sided, with 320K of format-ted storage per side. Both disk drivesperform well, except that the spindlemotor of the hard drive is noisy.

The bus structure of the Stearns uses96 -pin sockets. Since IBM PCs have 62 -pin sockets, Stearns users will not be ableto use plug-in boards dseigned for theIBM units. Six slots are available on themotherboard to enhance the unit's per-formance. Five are for Stearns -typeboards, two of which are used in thestandard configuration for the disk con-troller and the monitor display adapter.(In the version we tested, two more areused for 256K memory and a parallelport.) Stearns has combined severalfunctions on the two standard boards toease the requirements for extra slots.The disk controller card handles bothfloppy and hard disk operations and thedisplay card has outputs for both themonochrome monitor and a serial print-er. A sixth slot, similar to an IBM bussocket, is designed to accept IBM PCboards, but by the time of this writing,

42 Computers & Electronics

Stearns could not cite any cards thatwould function in the slot.

Other standard features include anRS -232 serial port and a battery -backedclock. Like many other computers, theStearns does not name the connectors,which could be frustrating to users.

KeyboardThe Stearns keyboard, manufactured

by Microswitch, is full-sized, with 94full -travel keys. It can be tilted into twodifferent positions. CAPS LOCK, PROG,NUM LOCK and s 1 -s4 keys have LEDs toindicate when they are in use. The key-board is somewhat less noisy than theIBM PC's and requires a rather lighttouch.

The main keyboard area has the stan-dard gwerty typewriter configuration.Dedicated keys include several that areunique to the Stearns unit. The STOP-SCNkey can halt scrolling of a list on thescreen; the PROG key instantly assigns toany key a character string that can be re-called by pressing the key and the as-signed single key. The assignments arelost on power off, however. The PRINTkey allows the screen contents to bedumped to the printer; the FUNCT keychanges the mapping of each of the func-tion keys (F1 -F10) to one of four posiblevalues. The new values are displayed online 26 of the screen so that the operatordoes not have to memorize the 40 possi-ble function -key operations. These "soft"keys are one of the Stearn's strong points.

A numeric keboard provides the fa-miliar arithmetic functions along withs1 -s4, which the manual states are to beused with Concurrent CP/M.

Video DisplayThe unit we tested came with the stan-

dard black and white 12" monitor whoserated resolution is 720 horizontal by 364vertical pixels. Character definition is

= Ern ci Era=SEMEMMINOMMIIIIMIMENNEMMIIMe.=OMME11111WINUMNIIMINIIIMMONIMEMINM

very good even out on the edges of thescreen. Even though color -phosphormonochrome screens are currently fash-ionable, this one was very satisfactory,even for extended periods of time.

A feature unique to the Stearns is adisplay format on line 26 that shows thecurrent value of the soft -function keys.Although the feature takes a little get-ting used to, it can save a lot of time inthe long run.

Stearns also offers 12" monochromemonitors with amber, green, or eggshellphosphor screens (for an additional costof $39) and a 15" monitor. The latter dis-plays 54 lines of text and two more linesfor status and soft functions, has a plug-in board, and sells for $1300. The mono-chrome display card that comes stan-dard with the unit differs from the IBMPC's in that it supports graphics. A colorcard is also available.

SoftwareStearns markets a variety of software

items tailored to their hardware. Wesampled operating systems and wordprocessing, database manager, spread-sheet, and communications applications.

Overview

Product Stearns ComputerManufacturer: Stearns Computer

Systems10901 Bren Rd. E.Box 9384Minneapolis, MN55440

Suggested Retail Price: S6135Dimensions: 22" W 1512" D

5' 2" HOperating Systems: Steams DOS,

MS-DOS 2.0Other Features: 8086 CPU, 384K

RAM, 10 Mb harddisk, 51/4- double -sided floppy drive

The operating system supplied withthe Stearns is IBM DOS 2.10 in the fa-miliar IBM package. ST -DOS and Con-current CP/M are available options.

Two word processors are availablefrom Stearns: the popular WordStar byMicroPro and WordPerfect by SatelliteSoftware. The database manager is Ash-ton-Tate's dBase II. (Everyman's Data -Base Primer by Robert A. Byers comeswith the Stearns unit to help the user getstarted.) Also available is MicroSoft'sMultiplan electronic worksheet, to han-dle the "what -if" questions.

An asynchronous control program(ACP) enables a user with a modem tocommunicate with other computers andinformation networks. Stearns includeselaborate documentation to help explaincommunications jargon. The HayesSmartmodem hardware is supported bythis software.

Such software packages as WordStarcan be purchased off the shelf and run onthe Stearns. Enhanced programs sold byStearns, however, include such nicetiesas the soft -key functions.

CompatibilitySince the Stearns is not hardware

compatible with the IBM PC, you canexpect some problems using softwarethat talks to the hardware directly, suchas disk utility programs, games, and win-dowing facilities.

The use of different controller chipsfor the CRT and the disk drives leads tosome trouble. The "acid test" programstake over the machine at the BIOS levelor even, in some cases, at the actual chiplevel, which causes problems for com-patibles that don't use the same BIOS in-terface or IC complement. A windowingfacility that runs on the IBM mono-chrome adapter would not operate onthe Stearns.

Stearns XTDesktop Computer1 square = 1 inch

(Continued on page 114)

-f

September1984 43

Introducing the newUnited they stand.

Programs in IBM's AssistantSeries are like actors in a play. Alone,

each gives an outstanding performance.Together, they've been directed to act well as

a troupe. (In the software world, this interactionis called "integration.")

Just as actors can easily performon different stages, these programs can easily

work on different IBM personal computers-from PCjr to larger systems like PC/XT.

How integrated software works.Want to get your facts and figures in order? Start with

IBM Filing Assistant. Then, to print the facts in tabular form,add IBM Reporting Assistant. To write about what you've

been working on (and make sure the spelling's accurate), useIBM Writing Assistant- the word processing program. Want to

put a chart in the middle of your text? Use IBM Graphing Assistant.It takes data directly from IBM Filing Assistant to turn numbers

into pictures. When it's time to think ahead with schedules andforecasts -get IBM Planning Assistant,* the spreadsheet program.

The finishing touch? IBM Assistant Solutions. They

Little Tramp character licensed by Bubbles Inc., s.a.

Available early next year."Prices apply at IBM Product Centers

IBM Assistant Series.Divided they stand.

make using IBM Filing Assistanteven easier. To help you with recordkeeping, several predefined, often -usedforms are included in eachSolutions package.

Learn one, learn them all.IBM's Assistant Series works hard for you.But the programs aren't hard to work. Many

of the menus, commands and function keys are thesame. So once you've learned one program, you're well onyour way to mastering the rest.

They're not hard to buy, either. Pick whatyou want uhen you want. Each program is less than $150.**

There's a demo in store.We've shown you how affordable the new IBM Assistant Series is.

But we can't show you how easy. Your dealer can. Simply ask for ademonstration. For the authorized IBM Personal Computer dealeror IBM Product Center near you, call 800-447-4700.In Alaska or Hawaii, 800-447-0890.

inIlMh.IME

Personal Computer SoftwareCirclet No. 41 on Fr* Information Card

ATARI'STOUCH TABLETANDCHALK BOARD'SPOWERPADTwo input devices withjust the right touch

BY CHARLES RUBENSTEIN

most microcomputers are con -trolled by keyboards, but joy-sticks, paddles, light pens and

touch -sensitive tablets are rapidly be-coming important ancillary input de-vices. We tested two examples of the lat-ter: the Atari Touch Tablet and ChalkBoard, Inc.'s PowerPad. The Atari tab-let (suggested retail price $89.95) is forthe Atari family of microcomputers andincludes a 16K ROM cartridge softwarepackage called AtariArtist. ThePowerPad is compatible with the Atariseries, the Apple II series, the IBM PCand PCjr, and the Commodore 64 andVIC 20. The PowerPad comes with aninterface cable for the particular com-puter you are using and for some modelsincludes drawing software. (We re-viewed the Apple II Plus compatiblePowerPad which retails for $149.95.)

The Atari Touch TabletThe Atari Touch Tablet, at nearly 1

lb, is very similar to the Koalapad,which we reviewed in September 1983.With dimensions of 9%" X 7"/18" X1%", however, the Atari tablet is 50 per-cent bigger than the Koalapad and its re-cessed active pad surface (5"/16" X49/16") is 70 percent larger. Both unitshave pairs of push buttons, one on eitherside above the active area, which func-tion much like the fire buttons on ajoystick.

The active area on the Atari consistsof two plastic sheets coated with resistivefilm. They are separated by an array ofover 1200 non-conductive bumps, each0.2" to 0.25" from its neighbor. The elec-tronics of the unit translates a "short"between the resistive layers on the padsurface into a resistive x -y coordinateoutput (similar to the operation of a joy-stick). The active area is protected by aplastic sheet that can be lifted up to al-low drawings, etc., to be inserted under-

The powerPad uses two plastic grid sheets to form 100 switches persquare inch or 14,400 switches per pad.

neath for copying or tracing onto thescreen.

With the Atari tablet, you can use atriangular stylus in addition to your fin-ger, a pencil, etc. The stylus, which plugsinto the rear of the unit, contains a con-venient push-button switch that allowsyou to operate the pad with one hand.Using it gives more the feeling of writingor drawing and is more accurate thanfinger pointing. The stylus is slimmerthan any finger and pinpoints its loca-tion better than an "averaged" locationfor a finger.

SoftwareThe software that comes with the

Atari Touch Tablet is Island Graphics'Micro Illustrator. It is a drawing pro-gram that uses a graphics menu for cre-ating color pictures on the screen. Theprogram is extremely easy to use, allowsfor either keyboard or stylus selection ofmenu elements, and either cassette tape

or DOS 2 diskette (DOS 3 is not yet sup-ported) storage/recall of pictures.

The Chalk Board PowerPadThe Chalk Board PowerPad is a much

larger touch tablet than the Atari model.Its dimensions are 20" X 17" X 1.5"and its weight is 4`/2 lb. The recessed ac-tive area is 12" x 12". Built into the leftside of the pad is a handle. However, theunit cannot be used while hanging fromthe handle; it is only convenient forright-handed use. The active area of thePowerPad is over six times the size of theAtari tablet area. Unlike the Atari tab-let, or the Koalapad, the PowerPad doesnot have push buttons for hardwareswitching. Instead, you can define anyarea of the tablet under software controlas a "command button." Location ofcommand buttons is guided by a plasticoverlay that accompanies each softwarepackage. For example, in the PowerPadversion of the Micro Illustrator pro-

46 Computers & Electronics

gram, five software defined (overlay) ar-eas of the pad's top edge are used insteadof switches for pen and menu control.Although much larger than its sisterpads, the PowerPad is comfortable usedon desk (or knee) and has non -slip feet.

PowerPad ElectronicsUnlike the analog (resistive film)

Atari or Koala tablets, the PowerPaduses crossbar switches to achieve 100discrete digitally defined positions persquare inch. The membrane switch"sandwich" has a top layer of protectiveplastic and foil shield. Underneath is aplastic sheet that has a y-axis grid of 10conductive 0.05" lines per inch withnon-conductive bumps between eachline. Beneath is another plastic sheetwith an x-axis grid. Together the gridsform 100 switches per square inch orabout 14,400 crossbar switches per pad.

Inside the case are 36 CMOS 4051 sin-gle 8 -channel (bidirectional transmissiongate) multiplexers, which function as ahardware scanning circuit. This circuittranslates "shorts" between x and y cross-bars into unique 16 -bit numbers. A maxi-mum of 20 complete scans is done eachsecond, one column at a time from thetop right-hand corner to the bottom left-hand corner. If you place an object on thepad, all covered switch closures are re-ported to the computer and the scan maybe slowed as the pad waits for the com-puter to receive a 16 -bit serial stream ofcoordinate data from each closure site.As noted earlier, the active area is pro-tected by a removable plastic sheet that iscustomized to each software program.

SoftwareAs with the Atari tablet, a version of

Atari's resistive pad connects toan interface board.

the Micro Illustrator software packagecomes with the PowerPad. The softwareis available on disk for the Apple II se-ries of computers.

Several other software packages areavailable, a few of which we looked at.One of them, the PowerPad Program-ming Kit, is an advanced graphics pack-age complete with test programs. It cov-ers the software techniques you need towrite your own programs using thePowerPad. You can create your ownpad -handling routines and establishyour own command buttons. As noted,command buttons function like the pushbuttons on the other pads, but tens ofbuttons are available rather than two.The buttons can be used as simple on/offswitches or to call subroutines, and theycan be defined within BASIC and/ormachine language programs.

Bear Jam is a program that uses 25command buttons. It is a children'sgame that encourages parents to workwith their preschoolers to recognize andcompare six basic shapes and six colors.Once the child outgrows the simplegames, a provision allows the parent orchild to create new games

LogiMaster is a game with a 34 -com-mand -button overlay that allows you toplay several variations of the popularMastermind game. It even lets you cre-ate your own version of the game.

Finally, Leo's Links is a golf game con-trolled with 35 command buttons. Youplay on predefined courses until you'reready to create your own course. This is agolf simulation that requires the player tounderstand the basic physics of golf.

Each program package consists of amanual, a software program on car-tridge/disk, and a plastic overlay show-ing the predefined command buttons.PowerPad software packages range inprice from $29.95 to $49.95.

Comments and ConclusionsI he Atari and l'ov.erPad touch tablets

give users the same general ability-toskip the keyboard and enter informationinto the computer by moving a finger or astylus over the touch -sensitive surface.Each has certain advantages. ThePowerPad has several software packagesavailable for it, and it can sense manypressure points simultaneously. TheAtari tablet is much easier to handle.

The big question, however, is whetheror not you would derive a continuingbenefit from either of these items. Youwould require a strong need for drawingsoftware to really benefit from either.The software programs that Chalk Boardoffers (other than Micro Illustrator) donot seem worth an investment of $150-$200 (including hardware). And MicroIllustrator itself has a narrow focus,whose novelty could wear off quickly.

To sum up, both products functionwell and are worth the price-to thosewho need them. 0

II -I-

I

Specifications _Product: PowerPadMarufacturer: Chalk Board, Inc.

3772 Pleasantdale Rd.Atlanta, GA

Dimensions: 20"W 17"D 1.5"HWeight: 4' 2 lbSuggested Retail Price: S149.95 (for

the Apple IIseries)

Features: Micro Illustrator softwareProduct: Atari Touch Tablet

Manufacturer: Atari, Inc.1265 Borregas Ave.Sunnyvale, CA 94086

_---

---_-"---

-

----

ATARI

_. Lt

-.-____,

\t... POWERPAD I Dimensions: 93/8" - 7'1/16" 13/8"Weight: 1 lbSuggested Retail Price: $89.95

-4---AtariArtist ROM cartridge

---Features:, ,-

7

11111 I 1 I i,

September 1984 PHOTOS BY BOB LORENZ 47

SOFTWARE REVIEWS,.SYMPHONY'Powerful new integratedsoftware from LotusDevelopment Corp., themakers of 1-2-3

BY LEE D. ZIMSKIND

Along-awaited integrated soft-ware package has arrived fromLotus Development Corpora-

tion. The makers of 1-2-3 have releasedSymphony. Rumors that Lotus was de-veloping a package to integrate wordprocessing with their existing productcirculated for months before the formalannouncement. When they finally un-veiled the package, it sounded too goodto be true: Not only would Symphony in-tegrate word processing, spreadsheetand graphics capabilities, but it wouldalso include communications and data-base facilities. So with some enthusiasmI began to review Symphony.

I was disappointed to find that I

would not be able to run Symphony onthe 256K machine that I had been usingto test other software. The minimum re-quirement for Symphony -320K bytesof RAM-gave me a good excuse to pur-chase the extra memory and the clockthat I had been wanting. Symphony alsorequires a graphics monitor if you wantto produce graphics on your screen-it

Overview

Product: SymphonyPublisher: Lotus Development

Corporation161 First St.Cambridge, MA 02142

Price: $695 ($200 to registered ownersof 1-2-3)

Computers: IBM PC or PC -XT,Compaq

HardwareRequirements: 320K RAM, two

320K floppy drivedisks or one 320Kfloppy drive and ahard drive

OperatingSystems: PC -DOS 2.0 or 2.1,

MS-DOS 2.0 or 2.1Features: Integrated system, word

processing, data basemanagement, graphics,and communicationscapabilities

is not possible to use the graphics capa-bilities on a standard IBM monochromemonitor with monochrome adapter.

Installing Symphony is time-consum-ing. First of all, you must make back-upcopies of all the diskettes in thepackage-six of them. Then you create aDriver Set, which provides Symphonywith the specifics about the hardwareyou are using-type of monitor, printer,modem. In theory, you can create asmany drivers as you want, but my pro-gram diskette only had room for two.Each driver is given a name by the user,with "Lotus" the default. The documen-tation is very thorough, and since theprocess of creating drivers is completelymenu -driven, the documentation is al-most superfluous. For example, when se-lecting a printer, you are presented witha list of 31 items to choose from.

knplementationThe basis of Symphony is a single

large worksheet composed of cells orga-nized into rows and columns-a maxi-mum of 8192 rows and 256 columns,subject to memory limitations. You ad-dress the cells by row number (from 1 to8192) and column label (A,B,...,Z,AA,AB,...,IV); for example, the addressof the cell in the 55th column and 15throw is BC15. Although you only addressthe cells in this manner when you are inthe spreadsheet mode, Symphony al-ways organizes the data this way.

At any time only one worksheet isavailable in the memory of the comput-er. You can organize this worksheet intodifferent areas in order to use the various

types of applications in Symphony; forexample, you may want to write a memousing word processing with a spread-sheet in the middle. Or, to be even moresophisticated, you may want to captureinformation from a remote computersystem within the body of a memo.

Symphony uses windows to give theuser a method of organizing theworksheet. Windows are defined as rect-angles within the worksheet throughwhich you can view a portion of the data.You may define as many windows as de-sired. You can use them to show differ-ent parts of the worksheet or overlapthem to show different views of the samepart of the worksheet. You must be care-ful when using overlapping windows be-cause changes to a cell in one windowmay affect the value in the other win-dows. The size of a window and its posi-tion on the screen are user -controlled:You can have a spreadsheet and an asso-ciated graph on the screen concurrentlyand see dynamically the results of"what -if" questions. For purposes ofwriting this review I created a windowwith an outline which I was able to con-sult while I wrote the text.

Symphony uses different kinds of win-dows for each of its applications-spreadsheet, word processing, graphics,communications and forms. The win-dow type determines the appearance ofthe window and the commands that areavailable. Some of the function keys areused consistently regardless of applica-tion (Ft, F6, F9, F10). Others, dependenton the window type (F2, F3, F4), makethings a bit difficult for the beginner but

48 Computers & Electronics

209G

IT'S A SMALL MIRACLE HOW HEWLETT-PACKARDPUT 656K OF MEMORY, LOTUS1-2-3,WORD

PROCESSING, A TELECOMMUNICATIONS MODEMAND COMPLETE IBM CONNECTABILITY INTO

EhaataZ

V 7-1I ;11

I

1 1

1 1 1 1 1 1 1 1 1 1 1

IrII !III tI Iri I

THE PORTABLE.For years business people had to choose

between the power of a desktop computer and thelimited capabilities of the first portables. Thatproblem was solved when Hewlett-Packard intro-duced The Portable.

The Portable is designed with more totalmemory than most leading desktop personalcomputers...656K in fact. That includes 272Kof user memory. So, The Portable's built-inbusiness software can work with enormousamounts of data.

1-2-3' from Lotus"America's most popularspreadsheet, file management and businessgraphics program, is permanently built into ThePortable. So is Hewlett-Packard's word processingprogram, MemoMaker. Just press the key andyou're ready to work.

The Portable even has a built-in modem andeasy -to -use telecommunications software to send

111111=111111111

or receive data using a standard telephone jack.If you use a Hewlett-Packard Touchscreen

PC, IBM' PC, XT or an IBM compatible youllbe glad to know that your desktop and ThePortable can talk to each other with the simpleaddition of the Hewlett-Packard Portable -Desktop Link.

The Portable's rechargeable battery givesyou 16 hours of continuous usage on every charge.

Finally, you can work comfortably on a fullsize keyboard and an easy -to -read 16 -line by 80 -column screen. And it all folds shut to turn ThePortable into a simple nine -pound box.

The Portable. A small miracle...perhaps.But then consider where it came from.

See The Portable End the entire family ofpersonal computers, software and peripherals atyour authorized Hewlett-Packard dealer. Call(800) FOR-HPPC for the dealer nearest you.

Setting You Free

rnItK1171;

ti

IBM is a registered trademark of International Business Machines Corporation. 1-2-3 and Lotus are trademarks of Lotus Development Corporation.

Symphony

are easy to remember with practice. Inaddition, a function key template isavailable.

The method of invoking commands isconsistent across all applications. Re-gardless of the type of window currentlyin use, pressing the F9 key displays a listof "services" or functions: Window,File, Print, Configuration, etc. The FIOkey displays a menu of alternatives thatdepend on the type of window currentlyin use; for example, the word processingmenu includes Search, Replace, Justify,and Format, while the communicationsmenu includes such functions as Phone,Log -in, and File -Transfer. You invoke acommand by moving the cursor to thedesired selection and pressing return. Aseach command is highlighted by thecursor, additional information about theselection is displayed in a text line abovethe options. Alternatively, you can selectfunctions by typing the first letter of thechoice. You can cancel selections bypressing the ESC key. Selecting a com-mand may result in the display of a newmenu of options. The names of the com-mands are reasonably self-explanatoryand the description in the text line is usu-ally sufficient, but more details are avail-able through a Help facility that is easyto use.

Although the documentation avail-able at the time of writing this reviewwas preliminary, it appears extensiveand clearly written. The package comeswith a tutorial, but, like the various ref-erence cards and templates, it was notcompletely implemented in time for thisreview.

Six diskettes are included in the pack-age, but after you have loaded Sympho-ny into the computer and placed theHelp and Tutorial diskette in the drive,the only function that requires you tochange diskettes is printing a graph.However, beginning a session, whetherwith a hard disk or a two -diskette sys-tem, is more cumbersome than withsome other packages.

The feature that differentiates Sym-phony from other products is its true in -

2224. 0211112 IMI16 MAU. IN

DM KRIM NFU NIFMK 111,

I 101111 IK0K1:011111111.0 101: 1:20 114? Ka it KI Sz 1110 NS 110 111 177 210 1 I

1 MI Ni I STO 111 11 111 I 0

1 if 1, ; in" til 'II N: I I7161' Im1 Iry in

III NO

I. lakilk NOplill&RI CI In 16 -MIK NMI/

,r41%tra inatrtrY1.1111.11.11

A communications session-airlinereservations on Compuserve

tegration. Because a window type is notpermanently assigned, it can be changedwith one key stroke. Thus you can easilyintegrate information of differenttypes-word processing, spreadsheet,graphs, forms-within one workingdocument.

I particularly liked the use of color. Itmade the screen easier to read and waseasier on the eyes than is only black andwhite on a color monitor.

Word ProcessingWhen you select Document as the

window type, the default format line isdisplayed at the top of the screen. Youhave complete control over the settingsfor the format line (left and right mar-gins; tab interval; left or even justifica-tion) through the Configuration Service.The window is available immediately forentering text. The default mode for wordprocessing is Insert mode, with the INSkey used as a toggle to switch to

21 Sworn rt. NM Was/

''! Ira 1 Omi./ 1111n '..11111i :SI

b... 0611 11.14 11.071 n0.* .

nratrn$ itfir...Intern al.NI.,

/IN7

.1 IA1.I

Taal Imam. 171 I. SIS t.001 ;

7

NCO 1Inons) 141 IN II/1 111? II

I ken

The Symphony spreadsheet is8192 rows by 256 columns

Overstrike mode. Word wrap is also as-sumed in the default settings.

Cursor control is good. You can movearound the document by character,word, line or phrase. It is easy to move tothe beginning or end of a line, para-graph, page or document. There is even aSpeed Search for finding the next occur-rence of a single character. With one keystroke you can, in addition, ask whereyou are on the printed document.

Most of the usual facilities are avail-able: copy, move and erase blocks ofdata; search and search -and -replace forstrings of data. You can specify auto-matic justification after execution of theblock and string commands. Unfortu-nately, after basic character insertion ordeletion you must invoke a format com-mand to adjust the text.

Unlike many other packages, Sym-phony treats underlining and boldfacingas special printer functions similar toitalicizing, superscripting and sub -scripting. As a result, it takes severalkeystrokes to use these features, andthey do not appear on the screen as they

Symphony can display dataand graph it simultaneously

will in the printed material. Lotus alsosupplies a set of international charactersfor use with appropriate printers.

Symphony supports multiple formatswithin the same document. You are ableto insert format lines at any point. Youcan name them and invoke them easilyby name. Using the multiple format fea-ture, you can also obtain different kindsof indentation within a document, in-cluding hanging indents. Although thereis no decimal tab, it is not a major short-coming because of the ease with whichyou can incorporate spreadsheets intoword processing documents. It is evenpossible to mix word processing andspreadsheet entries on the same line of adocument, although it is easier if theyoccupy different lines.

SpreadsheetAs one would expect of a product

from Lotus Development Corporation,the spreadsheet capabilities of Sympho-ny are extensive. Space does not permit adetailed comparison with 1-2-3. Howev-er, users of 1-2-3 will have some learningto do since the method of invoking com-mands is not the same: The Slash com-mands of 1-2-3 have been replaced withthe FIO commands in Symphony.

A "sheet" window contains a borderwith row numbers and column labels.The default setting for column width is 9spaces, but the width of a column may beeasily reset. All of the standard featuresof spreadsheets-moving, copying anderasing cells or ranges of cells-exist inSymphony. Also included are all theusual formatting capabilitiei for text andnumeric cells. Specifying cell calcula-tions is easy, and the usual mathematicaland business predefined functions exist.In addition, new functions have beenadded for string manipulation and statis-tical calculations.

Since Lotus 1-2-3 is well known andconsidered almost as the standard ofspreadsheet programs, I will not dwellon the spreadsheet capabilities of Sym-phony except to say that it contains all of

(Continued on page 111)

50 Computers & Electronics

Number One Warranty.Epson printers last longer. So we back them longer.

Every Epson printer sold in the U.S. isbacked for one full year on parts andlabor. That's four times longer thanthe "average" printer warranty.

That's also why we call it theNumber One Warranty.Taking care of No. 1.Epson makes the best-selling print-ers for personal computers in theworld. Part of the reason is a reliabil-ity rate approaching 100%, and stillclimbing.

And in the unlikely event that

you ew- do need service, i-_ is com- So frankly. we don't anticipateforting to know that there are more you'll have any trouble.than a tnousand Epson Service Cen- A logical conclusion.ters from coast to coast. If you want a prtntei that works and

It's also comforting to know that keeps on working, year after yearthe most you can pay for in the first after year. you want an Epson.year are ribbons and paper.Why are we so generous?Every single Epson component mustmeet rigid quality control s:andardsbefore assembly. And every finishedprinter is extensively tested before itleaves tie factory.

Number one. And built like it.

EPSON2780 Lomita Boulevard. Tbrrance. CA 90505 Call (300) 421-5426 for the Epson dealer in your area. In Califorria call (213) 539-9140.

EPSON II: a rekusteted t tadematk of Epson Coe porat on

NUTSHELLEasy -to -use informationmanagement for 16 -bitcomputers

BY TERRY EDWARDS

NUTSHFTINFORM?.

s()ME of us don't need really high-powered databases. We just needto be able to set up simple data en-

try forms and put in and pull out thedata. Of late, several such databases haveappeared, among them Ashton-Tate'sFriday! and Software Publishing's PFSFile. Another recent entry is LeadingEdge's Nutshell Information Manager.

Nutshell, which is intended for IBMPCs and "100% compatibles" (such asLeading Edge's own computer), was writ-ten to take advantage of the abilities of 16 -bit microprocessors (over 8 -bit micropro-cessors) to handle very large files. Hereare some of Nutshell's specifications:

Records per field: 60,000 Characters per field: 16,000,000 Character per record: 16,000,000 Records per file: 2,000,000,000 Files per disk: no limit (rather, lim-

ited only by disk capacity)

Leading Edge claims that Nutshellcan locate a unique record in 2 secondsin a 100 -record file. Nutshell automati-cally indexes all fields, automaticallymaintains indexes, supports five types ofdata (text, numeric, date, calculated, orsummary). It uses a hierarchical filestructure. Nutshell has the capacity toinput and output data in ASCII format.

Using NutshellInstalling Nutshell is simple and

straightforward. Because it is designedto run on the IBM PC and similar com-puters, installation only entails copyingthe original disk onto a formatted diskcontaining PC -DOS or MS-DOS. It isthen ready to run.

Nutshell is preinstalled for Epson dot-matrix printers. A choice of "other"isavailable. There is a separate installationprogram for the C. Itoh Prowriter print-er, called "Protrax," distributed byLeading Edge.

The Nutshell package contains twodisks: a tutorial disk and the master disk.The tutorial disk is a complete version ofNutshell with built-in prompts. Itpresents Nutshell's main features in astyle that is consistent and easy tounderstand. Prompted by the tutorial,you are led through Nutshell's basic op-erations, which eases the learning pro-cess considerably.

After a tour through the Nutshell in-struction disk, I turned to the masterdisk to see whether Nutshell could beput to practical use. I created a member-ship file that included some financial in-formation to test the program's compu-tational abilities.

The program came up on the screenjust fine, with a fancy line graphic of theNutshell logo. The first screen withwhich you interact presents the copy-right notice, a graphic of a file drawerand the command ENTER FILENAME:... Unfortunately, Nutshell does not al-low you to look at the disk directory atthis point-you're expected to know thefile name in advance. (There's a wayaround this, though. I created anAUTOEXEC.BAT file that, when thecomputer was powered up, listed thedisk directory and then, on command,brought up Nutshell.)

The Browse ScreenOnce you have typed in a file name,

Nutshell presents its "Browse" screen.The Browse screen is Nutshell's work

area. It can display the contents of afile-the field names and the contents ofthe fields.

If you have entered the name of a filecontaining data, the Browse screen willdisplay the first record in the file. If youtyped the name of a nonexistent file,Nutshell will display an empty Browsescreen and notify you that no such fileexists. Thus, the Browse screen acts as akind of "home base" from which you be-gin and to which you return when a spe-cific action or activity is complete.

You can retrace your steps from anyplace in Nutshell, by using the ESC key.It takes you back to the previous screen,that is, it will return you to the function

or screeen you were last using.The Browse screen is divided into

three parts: a header, the body and amenu. The left side of the header linegives the function key assignments:FILLELP, and cp7F2:MENU. Thesefunction key assignments, as well asthose of the cursor keys, are consistentthroughout Nutshell. The same key al-ways performs the same function. Whileyou are in the midst of trying to master anew program, you'll like knowing thatsome consistency exists.

On the near -right side of the headerline, Nutshell tells you how manyrecords are available. When you havejust brought up a file, the header line willshow the total number of records in thefile. When you have performed a selec-tive search, it will display the number ofrecords found in the search.

On the far -right side of the headerline, an arrow indicates whether you canuse the PGUP or PGDN keys on the PC'snumeric pad to move to the next record.With the same keys and the CTRL keyyou can also move to the end or begin-ning of a file.

At the bottom of the screen is dis-played a menu. Pressing the F2 key (seeabove) automatically places the cursorover the menu's first command. You canthen use either the right -arrow or left -ar-row cursor keys-or the first letter of thecommand-to move the cursor to thecommand you wish to use. To invoke acommand, just press ENTER. While thisis straightforward and relatively quick,Nutshell also gives you the option of by-passing the menu and entering a com-mand directly by pressing the ALT keyand then typing out the command. Thisis a nice touch that will increase the effi-ciency of those who like to use direct

(Continued on page 124)

Overview

Product: Nutshell Information ManagerPrice: S395Supplier: Leading Edge Products, Inc.

55 Providence HighwayNorwood, MA 02062

OperatingSystems (s): PC -DOS, MS-DOS

SystemRequirements: IBM PC or compatible

with 256K RAM.Two disk drivesrecommended

Opinion: Nutshell is a high -quality prod-uct that works as advertised.If you are looking for an un-complicated file managementprogram for home for small-business use, you would dowell to consider this one.

L_

52 a.vmputure CIL EACI.11.1

Casio's solar -powered scientific cal-culators put space-age technologyeasily within your reach.

Our FX-910 is the logicalchoice for students and engineersalike. At only $24.95, it gives youalgebraic logic, 48 functions and an8 -digit + 2 -digit exponent display-in a size that will fit as easily in yourpocket as its price will suit yourpocketbook.

At the same time, our creditcard -size FX-90 ($29.95) hasmembers of the scientific commu-nity flipping-over its 49 -functionflip -open keyboard. Made possible

Casio, Inc

September1984

by Casio's innovative sheet keytechno ogy, this handy fea-.uremakes complicated scientific equa-tions easier to solve because themajor function keys are displayedovers ze on their own keyboard.

Like our FX-90, our FX-450($34.95) has a 10+2 -digit LCDdisplay and a keyboard with touch -sensitive keys. But the keys aredouble size and the number offunctions increases to 68. Most im-portallly, it lets you calculate withthe speed of light-and eicht othercommonly used physical

Where miracles never ceaseCircle No. 2 on Free Information Card

Consumer Products Division: 15 Gardner Road, Fairfield, N.J. 07006 New Jersey (201) 575-7400, Los Angeles (213)803-341153

REAL LDDevices to link your micro with the physical

world for monitoring and control applications

44 F what practical use is a per-sonal computer?"

In the days before elec-tronic spreadsheets and word proces-sors, this question was asked by techno-skeptics everwhere.

"You can balance your checkbook,"was one standard reply.

"Learn to write programs," anotherwould answer.

"You can play games," someone elsesaid.

"I could use it to control my home,"still another would retort.

Home control! Ah, there was the stuffof dreams. Since the 1939 World's Fair(and probably even earlier) pundits havebeen predicting the automated home.Now, 45 years later, the low-cost person-al computer-the gadget that can realizethis vision-has arrived.

But where is the automated home?For one thing, electronic spreadsheets

and word processors attracted many of

the people who would have developedthe products necessary for a computer-ized home. For another, home automa-tion would just simply cost too much.Were automated "ham and eggs" reallyworth the thousands of dollars necessaryto get things cooking? Obviously not.

Nevertheless, a few souls did press on.Technology advanced. And today thereexists a surprising variety of innovativeand reasonably priced devices that allowusers to control or at least connect, their

54 Computers & Electronics

11111,111111111111

rIFIlarLit

computers to the real world. Called in-terfaces, these devices, coupled with apersonal computer make possible auto-mated home security, environment con-trol, even weather prediction.

Types of InterfacesComputers lead pretty sheltered lives.

Their insides, tightly controlled, low -noise, low -voltage habitats, cannot toler-ate extremes of temperature (or ex-tremes of anything, for that matter). Life

BY JOHN CONWAY

in the outside world, as we all know, isconsiderably rougher.

To have computers control the worldoutside them, we must use interfaces-devices that translate rough-and-tumblereal -world stimuli into electrical signals(for that's all computers understand) atlevels appropriate to their delicateworks. In turn, interfaces also beef upcomputers' relatively puny outputs sothey can convey instructions to otherdevices.

Computer interfaces fall into threecategories (Fig. 1): Computer -controlled switches (CCS).Electromechanical devices (such as re-lays) and solid-state switches (such astriacs) that provide simple on/off inputor output control functions.

Photo equipment credits; CVM andcounter, Hewlett-Packard; oscilloscope,Heath Co.; anemometer, Watrous & Co.,Inc.,; computer, Park Plaza Computer Cen-ter; computer screen by Nick Ciancaglini.

PHOTO BY BARRY BLACKMANSeptember 1984 55

Above and on the facing page are boards for interfacingcomputers to the real world and the devices they control.

Digital -to -analog (D/A) converters.Solid-state devices that convert the digi-tal output of a computer into analogvoltages or currents (or both) to be usedin the outside world. Analog -to -digital (A/D) converters.Solid-state devices that convert analogvoltage or currents into digital form in-telligible to computers.

Computer -Controlled SwitchesComputer -monitored switches pro-

vide the broadest class of readily avail-able real -world input signals. They mon-itor pressure, temperature, humidity,

light, sound, and liquid levels. They de-tect whether doors, windows, vents, orvalves are open or closed as well as a va-riety of similar "binary" conditions.Fortunately, as a source of inputs, com-puter monitoring of switches is simplic-ity itself.

To monitor a switch, the computer'sI/O port is programmed to test or "poll"the status of the input pin connected tothe switch of interest. As the switchopens or closes, the computer receives ahigh or low (1 or 0) input signal. If thevoltage passing through the switchranges between 2.4 to 5 V dc, a simple

Fig. 1. Interfaces fall into one of three categories.

CONTROLLEDINPUT

COMPUTERINPUT ,/

10010

1 1

1 00 0011

0100 110

CONTROLLEDOUTPUT

COMPUTER CONTROLLED SWITCHA

DIGITAL -TO -ANALOG CONVERTERB

A/D

ANALOG -TO -DIGITAL CONVERTERC

TTL or CMOS inverter provides a suit-able interface or "buffer." To monitorhigher voltages, input isolation is

necessary.An opto-coupler between the comput-

er and switch provides 1000 V or more ofprotection. This isolator will usually pre-vent a system from suffering damagefrom such accidents as short circuits orovervoltages.

The isolator consists of an LED thatilluminates a phototransistor whenpowered with a current of less that 20 to30 mA. Obviously, the state of the out-board switch, sensor or transducer de-termines whether or not current flowsthrough the LED. The diode's glow trig-gers the light-sensitive transistor intoconduction or ON. The TTL/CMOS-compatible output of the coupler pro-vides a corresponding binary HIGH orLOW signal optimized for use as a com-puter input. Since light connects theoptocoupler's input and output, onlythose signals exceeding the maximumdielectric voltage of this "light pipe" ar-rangement can cause a failure of the in-put interface.

Computer -controlled switching (theinverse of switch monitoring) is the mostbasic of all output control methods. CCSdevices span a wide range of switchingtechnologies from simple electrome-chanical relays to transistors, silicon -controlled rectifiers (SCRs) and triacs.The end application usually determinesthe choice of switch.

Electro-mechanical relay -based inter-faces are best suited for high -current ap-plications, where speed is not a signifi-cant factor. Their extremely low contactresistance (measured in micro -ohms)makes them especially useful for battery -based systems. Relays can easily handlehundreds, even thousands, of amperesand provide built-in isolation. Unfortu-nately, few offer response times muchfaster than 500 ps. Also, because theyare mechanical, the number of opera-tions before failure is reduced to tens ofthousands.

Solid-state switches or relays elimi-nate many of the problems associatedwith their electromechanical counter-parts, but not without revealing someproblems of their own. For example,transistors provide an excellent way to

56 Computers & Electronics

switch directcurrents and offerfast response times, long lifeand low turn -on currents. Yet, since thetransistor is essentially a one-way valve,ac control or reversing dc control typi-cally involves four transistor bridge cir-cuits. These can become quite expensiveas power ratings increase. Transistorsalso produce a voltage drop across the C-E or D -S junction-a drop that robspower and makes heat sinkingnecessary.

SCRs and triacs offer the fast responsetimes and solid-state reliability of tran-sistors and also higher current ratings,lower voltage drops and reduced costrelative to power. They are natural forhigh -power circuit applications. Never-theless, they suffer from a peculiar prop-erty called "latch -up." When an SCR ortriac is gated ON, the switch remainsclosed until current flow is reversed(during ac -zero crossing, for example, orvia capacitor -induced commutation) oruntil current flow ceases altogether. Thislimitation makes them unsuitable in sim-ple dc systems.

Wide Range of Switch -ClassProducts

Products that utilize CMS or CCStechniques and technologies range fromdevices consisting of nothing more thanopto-couplers or relays with transistor -buffer front ends to complex devices thatcommunicate over the ac wiring in yourhome and control appliances, lights, orjust about any device that lends its oper-ation to ON/OFF control.

Here are a few CMS/CCS productscurrently available:

The Switcheroo series of CCS mod-ules gives owners of most popular per-sonal computers an inexpensive controlinterface. The system consists of a com-puter -specific motherboard that acceptsa variety of electro-mechanical relaymodules. Modules include SPST,DPDT, polarity reverse and multi -vibrator functions. Each Switcheroomotherboard can hold up to eight con-trol modules. Expansion kits permitcontrol of up to 64 modules. Programlistings explore applications in such ar-eas as radiotelegraphy, telephone dial-

ing, and appliance andtoy control. Adapters allow

direct control of motor-ized/electronic Fischer-Technik, Lego,Erector and Capsela model building kits.

The A32 I/O and A16 I/O boards,plug -compatible with the Apple II, II +or Ile expansion slot, increase the inputand output capabilities of this popularpersonal computer. The I/O lines ofeach board are user -configurable in anycombination of inputs and outputs andeach open -collector line can sink 100mA. Boards also come equipped with up

to four isolated interrupt lines. Includedsoftware allows easy Applesoft "BASIC&" calls to control the units.

A companion product, the R16 T/Badds screw terminals to the I/O boards.

The CDFR controls up to two per-manent magnet motors from a conven-tional parallel output (printer) port.Four models cover an output range from6 to 48 V dc at 7 to 40 A for each output.

Fig. 2. D/A and A/D converters and a data acquisition system.

ANA_OG INPUTBEING >-

MEASURED

BR 4R

p

2R

D/P CONVERTER INTERNAL VIE\AA

COUNTSTOP/START

OMPARATORD/A ANALOG OUTPUT

COUNTER

" 1 0" oI I

I I I

I I I

D/A

C CONVERTER INTERNAL VIEWB

M U X

00

DIGITALWORD

4

I

INPUTCOMPUTER A/D ANALOG10-

CHANNELS

DATA ACQUISITION SYSTEMC

September 1984 57

INTERFACES

You can control speed and direction in-formation from your computer or by re-mote joystick (DIP switch -selected).BASIC PRINT, BASIC OUT or assem-bly language routines direct the opera-tion of the unit. Output circuitry forrelayless pulse width modulation is opti-cally isolated from the CDFR controllogic and your computer to eliminateground loops.

Users who desire an all -in -one classof real world interface should considerthe ADC -1. It combines a 16 -channelA/D data acquisition system with fourdigital inputs, six digital outputs, an acline carrier remote control (up to 256control modules possible) in a singlecompact unit. In operation, the ADC -1connects to any computer equipped withan RS -232 interface. Software listingsfor virtually all popular personal com-puters come as standard equipment. Awide variety of sensors, transducers, andcontrol modules of the BSR X-10 typeround out the system.

The SmartHome-I allows your per-sonal computer to act as a security sys-

tem and appliance controller. The sys-tem consists of a command control unitthat connects to any RS -232 port, a vari-ety of security sensors, output controlmodules (BSR X-10 or Leviton type)and applications software packages.SmartHome-I communicates to the re-mote control modules and sensors overthe ac wiring in your home. Applicationssoftware is icon -based and joystick pro-grammed. At present, the device is com-patible with Apple II and IBM PC andPCjr computers.

Converters Extend ScopeDigital -to -analog connecters fill many

needs for applications requiring continu-ously variable sources of power. Thesedevices convert digital signals into a volt-age or current proportional to the valueof the digital signal. Though a primitiveD/A converter can be fabricated from aresistor/capacitor filter, most basic D/Adesigns consist of stabilized resistor lad-ders with digital inputs from eight to six-teen bits in width (Fig. 2A). For each as-cending bit in a word, the D/A produces

an analog output with twice the value.D/As find use in music generation, mo-tor control, lamp dimming.

Since the A/D converter acts as a mir-ror image of the D/A, its strengths lie inits ability to convert everyday signalsinto varieties that are computer -under-standable. Interestingly enough, the ba-sic tracking type A/D is nothing morethan a D/A converter with a compara-tor/counter rear end (Fig. 2B). Circuitryinternal to the A/D directs the analoginput to one side of a comparator. Theother side of the comparator is fed by theoutput of a D/A converter. A counter(or similar circuit) quickly runs throughall possible digital combinations. Whenthe analog output of the D/A matchesthat analog input of the outside world,the comparator changes state. This sig-nals the A/D that it has found a digitalword combination equivalent to the ana-log input being measured. The conver-sion is complete! In practice, this entireoperation occurs in a few milliseconds ormicroseconds.

(Continued on page 104)

Clockwise from lower left are data acquisition systems from Vantec, Ragers Labs,Data Translation, Remote Measurement Systems, and Vaisala, Inc.

We Cut 5700 Off "Man's New Best Friend"!The 2 -Disk TRS-80' Model 4 Computer...Only 1299

Get our popular desktop computer atour lowest price ever! For power,range of applications and expanda-bility, TRS-80 Model 4 is the besthome computer value in the market.

Ideal for the Whole Family. WithRadio Shack's ready -to -run software,you can manage your home budgetwith ease, monitor stocks and invest-ments, keep a personal filing system,prepare letters and other documentswith word processing, and muchmore. Kids and grownups alike willenjoy playing fast -action and intri-guing strategy games. And everyonein the family can learn to program us-ing the built-in BASIC language, oryou can use more advanced lan-guages available on diskette.

144: fik.

lin I " SCBIPSIT

El] fiser riusercale

Two -Disk TRS.80 Model -4 (26-1069) was $1999.00 in Cat RSC-11 Prices apply at partic pains Radio Shack stores and dealersSoftware shown not included. CP/M Plus is a trademark of Digital Research CitiLine is a s.ervce mark of Citicorp

Built -In Features. You get a 64,000 -character memory (expandable to128,000), two built-in disk drives forfast loading and storage of programsand data, an 80 -character by 24 -linevideo display, a parallel printer portand an RS -232C communicationsinterface.

Large Software Base. The Model 4runs all Model III TRSDOS softwareand supports CP/M Plus (optional).This means you have access to moresoftware than other computers. TheModel 4 supports a high resolutiongraphics option that provides for ex-cellent graphic display of informa-tion. Expand with additional floppydisk drives or even add up tc 60

million characters of hard disk stor-age. And by adding a telephone mo-dem and software, you can accessnational information services byphone and get everything from newsand stock market reports to elec-tronic mail services to special inter-est clubs and games.

Come in Today! Get your TRS-80Model 4 at Radio Shack ComputerCenters, participating stores anddeaers nationwide. It's the one com-puter for everyone in your family!

Radio ihaeliThe Technology Store

A DIVISION OF TANDY CORPORATION

///1/e),No.

/ cp*c0-

/ ocef

//.<rece's4) 4P

/ ce

ommignimmummir/e#cst/// 6 e

0 C'

KEYBOARDSONE POWER AT YOUR FINGERTIPS

The inner workings of the primary pathway to your machine

BY Ti BYERSCOMPUTER keyboards are likesteering wheels on cars: If thefeel is not just right, operating

the machine is a chore, not a pleasure.And, as any veteran micro user knows,although keyboards may look alike, theyvary dramatically in mechanical struc-ture and function.

Keyboards were invented along withthe typewriter. They made writing quick,convenient and-above all-clear. To-day they are the means of communicat-ing with computers, the interface be-tween the user's thoughts and theenormous processing powers of thecomputer.

Keyboard TechnologyA keyboard is really nothing more

than an array of switches arranged in alogical order. Pressing a key activates anelectrical signal that the computer inter-prets as information. There are severaldifferent ways by which the electricalsignal can be generated by the key ac-tion. Two are capacitive switching andferrite core switching.

Capacitance switching has foundwidespread appeal because of its lowcost and high reliabilitiy. Basically, a ca-pacitor is nothing more than two piecesof metal separated by an insulator. Thevalue of the capacitance is inversely pro-portional to the distance between thetwo plates. In a capacitive switch, onemetal plate is fixed to a solid backing; thesecond plate is attached to the keyswitchplunger (Fig. 1). When the plunger is de-

pressed, the movable plate comes closerto the bottom plate, increasing the ca-pacitance of the switch.

The plates of the switch are connectedto an oscillator whose frequency is deter-mined by the capacitance. As you in-crease the capacitance by moving theplunger down, the oscillator's frequencydecreases. A phase -locked loop (PLL)senses this frequency and removes theinput signal. To prevent erroneous inter-pretation of a partial key depression, thePLL sets a threshold-the minimum fre-quency change that must be detected fora signal to be generated.

Ferrite core keyswitches also rely onchanging electrical parameters. Theyuse inductive coupling. When you de-press the key, a ferrite rod on the key-stroke plunger slides into a transformercore (Fig. 2). The transformer, looselycoupled, is composed of two coils of wireclose to each other: a primary power coiland a secondary sensor coil. When therod is inside the transformer, it increasesthe coupling between the coils. Then apulse generated in the primary coil istransferred to the sensor coil and an out-put signal is generated. When the switchis released, the concentrated magneticfield and the coupling between the coilsdisappears.

Ferrite core switches achieved wideacceptance in the early 1970s and havebeen used successfully on many comput-

7:1 Byers is the author of numerousbooks on electronics and computers.

er keyboards. They offer high perfor-mance at a relatively low price and arevirtually immune to failure due to dust,spills and other common office hazards.

Mechanical SwitchesThe old standby in switch technology

is, of course, the mechanical switch.Long before there were ferrite core or ca-pacitance devices, mechanical switcheswere hard at work. Unfortunately, theyare prone to contact bounce. (When youpush the key once, the switch contactsmay open and close several times.)Debouncing circuits, however, are fairlycheap to incorporate, so mechanical key-boards are still in wide use.

Mechanicals are divided into key-boards and keypanels, depending on theway the key unit is constructed. A key-board is an assembly of individualswitches placed on a common field. Thetypewriter is a perfect example of key-board design. Keypanels, on the otherhand, are built as one unit, with the iden-tity of the individual switches hidden be-hind an overlay, usually of plastic. TheTimex 1000 uses a keypanel.

The hard mechanical keyboard, theoldest of the mechanical keyswitchingtechnologies, generally performs switch-ing with either gold cross point or bifur-cated wiping contacts (Fig. 3). The latterare the type of contacts you would nor-mally find in a wall switch or other elec-trical equipment. Although they costvery little, they suffer from excessivecontact bound and metal fatigue, which

PHOTO BY MICHEL TCHEREVKOFF

September 1984 61

Keyboards

eventually overcome them. Recent ad-vances in switch technology, however,have greatly reduced contact bouncewhile extending switch life, and you willfind these contacts in many keyboarddesigns.

Keypanels are relatively new to com-puter users. Switch designs for key -panels come in three distinct types:domeswitches, membranes and conduc-

tor. The dome's inherent flexibility al-lows it to snap down with a sprightlyfeel. When released, it springs back to itsoriginal shape.

A plastic overlay is normally laminat-ed over the field of domeswitches. Theplastic serves two purposes. First, it sealsthe keypanel components from contami-nation by moisture and dirt. Second, itusually sports a legend with symbols

AFTERMARKET KEYBOARDS

...illii00111111111111111.1ilir-.0111.11111111111113111011111111111111110r

4111111111111011111110011111111111100011101a a IS 1.1111111111111111111111111111101111111111imm.

fnrvwIPPIISMIIIIIIIIIIIIL

Key frolic's 5151 keyboard replacesIBM's with a more logical layout.

you are probably now looking atyour present keyboard and won-dering what you can do to up-

grade it to the quality you would like tohave. Well, you can do a lot.

Aftermarket keyboards are big sellers,especially among IBM owners. WhyIBM forsook its finely tuned Selectrickeyboard in favor of the one it used on itsPC is anybody's guess.

Fortunately, you aren't stuck with it.No fewer than half a dozen independentkeyboard manufacturers offer replace-ment keyboards for the PC. They rangefrom capacitance to mechanical.

Despite its apparent bumbling, IBMhad the foresight to make its keyboards

detachable. One of the ergonomic sug-gestions put forth by the DIN committeewas removable keyboards. That was onesuggestion IBM decided to follow.Changing keyboards is as simple as pull-ing the cord out of the old board andplugging in the new one. In a matter ofseconds, you can change the entire ergo-nomics of your computer.

IBM is not alone in this respect, not bya long shot. Replacement keyboards areavailable for the Apple, Victor and manyother machines. In some cases, however,you may be required to complete the ex-change, but none are so complicated thatthe entire job cannot be performed in lessthan an hour. 0

tive elastomers.A domeswitch keypanel (Fig. 4) con-

tains stainless -steel, dome -shaped disksattached to a printed circuit board. Thelatter is etched with silver-plated copperlines, one of which passes under the cen-ter of the dome and another that con-nects to the dome. When you depress thekey, the pressure collapses the dome,making contact with the center conduc-

that correspond to the switch functions.These graphics are essential to the userbecause most keypanels are flat, opaquestructures, without graphics, so youhave no hint where the switchpads arehidden.

Conventional membrane keypaneltechnology uses three layers of polyesterfilm sealed under a plastic overlay (Fig.5). The outer layers of the film are

KEY CAP

-- PLUNGERSPRING

SUPPORT

TOP BOTTOMPLATE PLATE

INSULATOR

Fig. 1. Capacitance keyswitch.

screened with a pattern of switchingpoints using conductive silver ink. Theimages are aligned so that correspondingswitch points touch. Separating thesetwo layers is an insulating sheet of poly-ester. Holes are punched through the in-sulating sheet where the contact pointsare to meet (Fig. 6). When you applypressure to the keypanel, the plastic de-forms, allowing the two metal screeningsto make contact through the hole.

The thickness of the spacer layer is amajor factor in the actuation force of theswitch, with switch travel often mea-sured in thousandths of an inch. The en-tire keypanel is usually glued to a rigidsubstrate to prevent the keyboard fromflexing during normal operation.

A cousin to the membrane keypanel isthe conductive rubber, or elastomer,keyswitch, shown in Fig. 7. An elasto-mer switch is constructed from a singlesheet of rubber and a printed circuitboard. Into the thin rubber sheet ismolded a dome lined with a carbongraphite. The printed circuit board isprinted with two plated copper pathsthat pass very close to each other; bothtracks pass under the rubber dimple.

Unlike membrane keypanels, elasto-

TOP

PLUNGER

FERRITEROD

-HOUSING

SECONDARYWINDING

PRIMARYWINDING

SPRING

Fig. 2. Ferrite core keyswitch.

62 PHOTOS BY BOB LORENZ Computers & Electronics

mer keyswitches need no insulating lay-ers. The contour of the dimple keeps thecarbon pad from touching the circuitboard wires in its relaxed state. When therubber dome is depressed, however, thecarbon conductor makes contact withthe copper strips and completes thecircuit.

Until recently, elastomer keyswitcheshad relatively short lifespans, which lim-ited their acceptance. New develop-ments in elastomer technology (mostlyby the Japanese), however, have extend-ed keyboard life by more than 500percent, and conductive elastomer tech-nologies, like those in membrane appli-cations, have been used in eitherkeypanel or keyboard construction.

ACTUATOR

SNORTING

NHOUSI

BAR

G

Ilk, FIXEDCONTACTS

RETURNSPRING

Fig. 3. Mechanical keyswitch.

ErgonomicsA lot of attention is given today to

ergonomics-the investigation of whatmakes interactions between humans andmachines most effective. The goal of er-gonomics is standards that will net thegreatest efficiency by matching theneeds of one to the other. Of course, thekeyboard is perfectly suited for ergo-nomic concerns.

Ergonomic considerations focus onkeyboard profile, the distance from thebottom of the keyboard to the top of thekeys, and the length of the keystroke, orthe distance the key must travel to com-plete the switching function. Generally,keyboard profiles are divided into threecategories: low, DIN (also called stan-dard ergonomic) and micro.

The low profile, established in 1975,has a typical keyboard height of 1.5".Before introduction of this standard,keyboard profiles ran 2" and more, withno two alike. Low -profile keyboardsnormally use full -travel keyswitches thathave strokes ranging from 0.150" to

OVERLAY

METALDOME

CONDUCTOR

SUBSTRATE

Fig. 4. Metal dome in keypanel gives tactile feedback.

0.190". In this range is the distancefound on most Touch -Tone telephones.Low -profile keyboards are the favoriteof keypunch operators and wordprocessors.

The DIN standard keyboard was de-vised in 1980 by West Germany's Deut-sche Industrie Normenausschuss. TheDIN specifications set the maximumkeyswitch height at 30 mm, with thekeyboard mounted at any angle betweenzero and 10 degrees from horizontal.Keystroke travel is set between 0.120"and 0.150".

Microprofile keypanels are the resultof membrane -type keyswitches, like theconventional membrane keyswitch andthe conductive elastomer keyswitch.Key height is at most 3/4"; there is nolower limit. The keystroke travel dis-tance depends upon the keypanel andthe technology employed. A typicalmicroprofile keypanel uses keystrokes of1/16". Membrane keypanels often havekeystrokes of less than 0.015", which hasearned them the nickname "touchpanels."

Keyswitch FeelAnother ergonomic consideration is

the feel of the keyswitch. Feel is very

important because it lets the user knowwhen a switch has been actuated andwhen it hasn't. Linear keyboards pro-vide feedback by the feel of the length ofthe stroke. The operator assumes con-tact is made when the key bottoms out.Touch -Tone phones use linearkeyswitches.

Shorter stroke keyboards, however,often use switches that give tactile feed-back. They require a greater force to ini-tiate the switching action than to sustainit. You feel this action as a click on thefingertip. Domed keyswitches are tac-tile. Depressing a domeswitch, you feelthe metal cover snap over at the point ofcontact.

Other types of keystroke feel includesponge and touch. Sponge switches havesprings inside them that increase fingerpressure as the keys bottom out. It is aform of linear switching. Touch switcheshave no feel to them at all. A familiar ap-plication is the membrane keypanelfound on a microwave oven. Audio gen-erators are sometimes used with touchpanels to give audible feedback. A mem-brane keypanel can also be made tactile,by installing a metal dome over themembrane sandwich prior to laminatingthe overlay.

On domes itch keypanel, each lead at left is a row or column.

Fig. S. Membrane keypanel with legend overlay.

Key ContourThe contour of a key provides the

nesting the fingertip experiences whenusing the keyboard. Flat keytops arecommon and the least expensive to man-ufacture. Unfortunately, they don't

Keyboard LayoutsKeyboard layout is like religion and

politics: not a good topic for light con-versation. What is satisfactory for oneperson is absolutely unacceptable toanother.

GRAPHICSOVERLAY

MEMBRANE

SCREENEDPATTERN

SPACERcirOPENING

SPACER

MEMBRANE

SCREENEDPATTERN

RIGIDBACKING

Fig. 6. Patterns screened on membranes form switch contacts.

conform well to the shape of the humanfinger. By far the design most ergonomi-cally satisfactory is the sculpturedkeytop. In fact, sculptured keys are whatDIN stipulates for its ergonomic key-boards. Sculptured keytops are used fortypewriters and telephones. The keyshave hollowed tops that accommodatethe fingertips and provide natural wellsthat prevent the fingers from readilysliding off the keys.

Keypanels, obviously, don't havekeytops. More often than not, the panelis flat with no contour to it whatsoever.Bumps and ridges are sometimes moldedinto the keypanel to make locatingkeypads easier. In some cases, to helpposition the operator's fingers, embossedrims are formed around the keypad area.

Most manufacturers tend to stay withthe tried and proved arrangement of thetypewriter keyboard. In this type of key-board, the keys are in four rows of ap-proximately 10 to 12 keys per row. Eachrow is offset to the row above it to make

it easy to reach the keys when touch typ-ing. Touch typing is the game yourteacher played with you in typing classby removing the letters from the keytopsand forcing you to memorize thekeyboard-no peeking permitted.

All keyboards today have legends.Contrary to what you may think, the leg-ends aren't there for the benefit of ushunt -and -peck typists who staunchlyrefuse to undergo the rigors of learningto use more than one finger. No, the leg-ends are there to let you know what lay-out the keyboard has.

The design familiar to most typists isthe QWERTY system. Look at the sec-ond row on your keyboard. Notice howthe letters read QWERTY from left toright? This is the keyboard most schoolsteach, and it is by far the most popular.

Its layout is designed to accommodatethe movement of the human hand. Thepattern is supposed to lead to the mostefficient use of the fingers and producethe fastest results without causing thetypebars of the machine to jam. Not ev-eryone agreed. It wasn't long before acompeting design, known as the Dvoraksystem, made its debut. Underlying theDvorak keyboard is the assumption thatthe most -used keys should be placedwhere they're easiest to reach.

This conflict began more than 100years ago, just after the invention of thetypewriter, and hasn't yet cooled. (Somealert readers may note a parallel betweenIBM and Apple.) A few keyboards, forexample, the Apple I1c, have circum-vented the problem by offering both sys-tems at the flick of a switch.

And last, and probably least, is theABCDEF approach. But even devouthunt -and -peck typists find this arrange-ment clumsy at best, and, fortunately, ithas little application in computers.

We spend increasing amounts of timewith our fingers on the keys and less andless with pens and pencils in hand. Still,most of us are not yet able to interactwith machines in ways that are fasterand more effortless than are keyboards.Until such means are widespread, everymillimeter of keyboard design counts. 0

Fig. 7. On elastomer keyswitch, carbon pad closes circuit.

wireLf------- LEGENDsenew-dr OVERLAY

HOUSING/BEZEL ---41.mAWERUBBER

BUTTON

CARBONPAD

CONCUCTORS

CIRCUITBOARD

Whether you're pursuing a proud hobby...or earninga living, don't trust the accuracy of your measure-ments to anything less than Heathkit instruments.Our kits are a little bigger, more rugged than "dis-posable" instruments that discourage self -servic-ing. Performance is superior, too. Just check thespecs on our new 10-4360 Scope and 10A-4200Time -Voltage Module.Get to know our full line of instruments. They'rebuilt by experienced hands. Your hands. So they'llsave money and help you do a better job. Heatihkitinstruments. Don't trust your pride or money toanything less.

Heathkit instruments. Some buythem for pride...some, to sate money.

Prokssional specs for serious usersIG-4244 Scope Calibrator. <1 ns 1M-2264 DMM. True RMS read -

rise time. 0.015'° tolerance. ings. Analog metering. too.10-4205 Dual -Trace 5 MHz Scope.

IT -2232 Component Tracer.Checks circuits without power.

4 IP-2718 Power Supply. Fixed oradjustable supoly. 5 to 20 VDC.[51 16-1271 Function Generator.Sine, square, triangle waveforms0.1 Hz to 1 MHz.

16 IG-1277 Pulse Generator. 100 nsto 1 sec width pulses.17 IT -5230 CRT Tester. Tests.cleans, restores CRT's.

IM -2420 Frequency Counter. 5Hzto 512 MHz. Ovenized oscillator.Includes period and frequencymodes.

IM -2215 Hand-held DRAM. FiveDC ranges. Accuracy: -:0.25°. ofreading - 1 count.

IT -2250 Capacitance Meter. 199.9pF to 199.9 mF Auto ranging

10-4360 Scope and IOA-4200Time Voltage Module. Triple trace.60 MHz. <7 ns rise time. I0A-4200controls CRT cursor and multi-function display

lieathkit instruments.The professional

instruments.

measurementforyourmoney

A subsidiary of Zenith Electronics Corporation

Circle No. 10 on Free Information Card

--1Take another look at the instrumentsyou should be building.

FREECOLOR HEATHKIT CATALOGMail th s coupon to:Heath Company. Dept. 010-214Bentor. Harbor, MI 49022

Name

Address

City

State ZipGX-393 ..JCompany

AT&T BREAKSTHE SPEED BARRIERNew technology will soon permit dial -up users to communicateat 56,000 baud-in full duplex

BY PATRICK MCDONNELL

EVERYONE who owns a modem remembers the agony ofdeciding whether it was worth the extra money to be ableto send at 1200 rather than 300 baud. Soon that will be

history. AT&T has announced it is testing circuitry that will al-low ordinary telephone lines to transmit data at a rate of 56,000baud. If that isn't enough, the new service will be in full duplex.

This high-speed network, called CSDC (circuit switched digi-tal capability), will enable users to transmit data more cheaplythan sending computer tapes. Facsimile transmission will bevastly improved. Using the proper analog -to -digital conversiontechniques along with CSDC, users will also be able to send high-fidelity music and speech more easily than is currently availableeven on special dedicated lines.

All this is likely to be in place by the end of1985. Right now it isbeing tested by Illinois Bell.

Megabauds from Ma BellCDSC is the outgrowth of work at Bell Labs begun in the early

1960s to raise the fidelity of phone calls, lower their cost, and in-crease their speed. Before those efforts could produce CSDC theyyielded piggyback calls, pulse -coded modulation with the T -car-rier system, elctronic switches, "smart" switches, and time -com-pression multiplexing.

Everyone over the age of 30 remembers the hissing and roaringthat accompanied long-distance calling over 20 years ago. Untilthe early 1960s two or more conversations were sent over thesame lines by a technique known as frequency division multiplex-ing or frequency translation. Since telephone lines, or loops, cantransmit signals with frequencies as high as 150 kHz and voiceonly has a bandwidth of 300 to 4000 Hz, telephone engineerswere able to piggyback as many as 16 conversations on one line.They split the two -wire conversation into a four -wire transmit -receive arrangement and sent it on carrier tones.

Multiplexing was the backbone of the long-distance networkfor years. It suffered from two major shortcomings, one technicaland one economic. Since the wires were carrying analog signals,every time they passed through an amplifier in a repeater station,noise was amplified along with the signal. The longer the calltraveled, the more amplifiers it passed through, and the morenoise it collected.

The second problem was that it took four parallel lengths ofwire to handle 16 conversations. The phone company regardedthis quadruplication as less than economical. Not only was thereall that wire, but there had to be many repeaters on the line toamplify degenerating analog signals. Other problems-distor-tion, echo and crosstalk-made the repeater circuitry extremelycomplex and expensive.

The T -Carrier SystemIn the early 1960s the T -carrier system, a higher -grade trans-

mission network, changed everything. Based on pulse codedmodulation, it was able to stack 24 conversations instead of 16.Pulse coded modulation (PCM) is a multiplexing scheme inwhich the analog signal is sampled at regular intervals and thentransmitted as a series of pulses on the phone line. With the signaldigitally encoded, the function of the repeater is different. Insteadof ampliying the original signal, as it did with frequency modula-tion, the repeater can simply recopy the bit pattern, effectivelygenerating a new signal. Transmission noise was greatly reduced.

Bell also changed the method for multiplexing signals. Timedivision multiplexing, which permitted Bell to send multiple sig-nals on the same line by sampling the individual signals, replacedmodulating carrier frequencies.

Patrick McDonnell is a free-lance writerwho specializes on computer topics.

PHOTO BY BARRY BLACKMAN

67

Sincethe pulse codedsingals are digital words of a defi-nite length, it takes a definite amount oftime to transmit each one. By samplingseveral different lines in sequence andtransmitting resulting digital words in aparticular order, with time division mul-tiplexing it became possible to send mul-tiple signals on the same line.

The biggest obstacle to increased mul-tiplexing and high speed data transmis-sion was the time it required to switchfrom one line to the next. The standardswitch in the telephone ccompany wasalways some sort of relay. Since these areelectro-mechanical, even the fastestswitch needed several milliseconds tooperate as well as extensive supportingcircuitry. These requirements limitedthe maximum number of lines a tele-phone exchange could handle to 65,000.With the development of electronicswitches that could change state in a fewnanoseconds, each switch was able tohandle 65,000 lines. Finally the baudrate could leap.

The higher baud rate for time divisionmultiplexing became a function of thespeed of the new electronic switches-several nanoseconds, the rate of the fre-quencies the local metallic loops couldhandle -150 kHz, and the rate at whichthe analog signal had to be sampled. An-alog sampling had to be at least twice themaximum frequency present in the sig-nal. Since voice has a maximum band-width of about 4000 Hz, the samplingrate was set to be 8000 Hz. To digitize an

68

an slogsignal, an 8 -bitword is created for eachsample: 7 bits are used to encode the sig-nal. and the eighth bit is used for variouscontrol purposes. Since the T -carrier canmultiplex 24 channels, each section ofthe encoded signal has to carry 24 8 -bitsamples plus one extra bit to signal theend of the section. Therefore, there are24 x 8 + 1 = 193 bits being transmit-ted at a rate of 8000 per second. Multi-plying yields 1544 kHz, which translatesinto 1.544 megabaud, the basic carrierrate of the T -carrier system. The maxi-mum rate at which data can be sent overany one of the individual channels of thesystem is 8 bits at 8000 H. or 64

Digital office timing componentsynchronizes clocking functions.

CSDC equipment being testedin New Jersey Bell's central

office in Murray Hill, NJ.

kilobaud.The T -carrier

system was operatingat the end of the 1960s. After

initial testing, AT&T introduced itsdataphone data communication service,based on it. The new service offered endusers high -quality voice services and datatransmission at speeds of 2.4, 4.8, 9.6 and56 kilobaud. The drawbacks were, amongothers, that special transmission lines notavailable everywhere, called the digitaldata system, had to be used. To expandthe service AT&T introduced an im-proved, smart, electronic switch and"dataports," which provided a means ofdirect individual access to any of thechannels in the network similar to directmemory access and interrupts in a com-puter. Now local telephone companiescould dial into the system, and the net-work grew quickly.

The smart switch incorporated micro-processor technology. By using onboardmemory the switch could diagnose itself,monitor the quality of the transmissionlines it was controlling, and, in general,increase the capacity of the digital datasystem and guarantee the integrity of thedata it carried.

The switch could also be programmedto recognize which lines were carryinghigh-speed data and route the transmis-sions over lines and through exchangesthat were equipped to handle them. Itcould easily eliminate from the digitalnetwork exchanges with only conven-tional equipment. The resulting digital

PHOTOGRAPHS BY STEVE BORNS

Computers & Electronics

56 Kb/sDIGITAL

TERMINAL

CSDC LOCALCENTRAL OFFICE

ACCESS TELEPHONE

USER LOCATION NETWORK

tz.1142 -WIRELOOPr- -

AVD

2 -WIRELOOP

DIGITS LCARRIER

INTERFACE

T -GAFF? ERLAVDL___

KEY TO ABBREVIATIONS:

CSDC CENTRAL OFFICE

DCT

LECTFIONICSWITCHNG AVDSYSTEM - T -CARRIER

CSDC CENTRAL OFFICE

TIE TERMINAL INTERFACE EQUIPMENTNCTE: NETWORK CHANNEL TERMINATING EQUIPMENTAVD: ALTERNATE VOICE /DATIkMFT: METALLIC FACILITY TERMINALOCT. DIGITAL CARRIER TRUNK

DCT DCTLECTRONIC

AVD SW ITCHING AVDSYSTEM

7

LONG -HAULDIGITAL NETWORK

LECTRONICSWITCHING

SYSTEM

Fig. 1. Block diagram of the circuit switc led digital capability

signal paths, based on a combination ofthe T -carrier system and the new pro-grammable electronic switch, was calledthe digital carrier trunk. The problemleft was to provide full duplex 56-kilobaud service to any conventionaltwo -wire telephone line.

Time Compression MultiplexingThe local loops and switching circuit-

ry were already capable of handling thebandwidth necessary for high-speeddata transmission. The solution to theproblem of bringing CSDC to conven-tional telephone lines was found in atechnique known as time compressionmultiplexing, a refinement of the timedivision multiplexing scheme for the T -carrier system (Fig. 1).

In time compression multiplexing,data sent on local loops are grouped intosections of equal length. Each of thesesections is compressed and sent over thelines in a controlled burst at a higher

rate. When a section reaches the receiv-ing end, it is expanded again and re-stored to its original condition.

Full duplex operation is made possibleby carefully synchronizing the receivedand transmitted bursts so that when thestation at one end is receiving, the one atthe other end is transmitting. How largeeach section of data should be is a func-tion of not only the data rate but also thequality and length of the loop. Designingfor the worst case set the size of the datasegment at 199 bits and the burst rate at144 kilobaud. Remember that the basicrate of the T -carrier system was set at1.544 megabaud, more than ten timesfaster. Since the maximum baud rate forthe user of the system is 56 kilobaud, thecompression necessary is on the order of2.5 to 1. In each burst, 168 bits are re-served for the transmitted data. 4 bits arefor control, 3 bits for synchronization,and the remaining 24 bits for futureexpansion-the system is capable of data

Fig. 2. Timed compression multiplexing burst timing.

3 MS

DATA INCO TO SUB '

TRANSMITTED FSUB TO COSIGNALS

DATA OUTCO TO SUB 1

CO TO SUB

SUB TO CO = SUBSCRIBER TO CENTRAL OFFICECO TO SUB = CENTRAL OFFICE TO SUBSCRIBER

SUB TO CO

MS

CO TO SUB

TIME

TIME

TIME

September I9114

transmission at 64 kilobaud.As can be seen in Fig. 2, the time al-

lowed for each burst is 3 milliseconds,but the actual burst only lasts 1.34 milli-seconds. The margin of 1.66 millisec-onds allows for propagation delays andeliminates the possiblity of echoes byproviding time for the received burst todecay before the transmitted burst issent.

Constant checking during the opera-tion ensures that the burst remains syn-chronized. In fact, absolutely no trans-mission takes place at all until both endsare locked to each other. When datatransmission is started, both the trans-mitting and receiving ends are slaved toa master clock at the AT&T exchange.As soon as clock synchronization isachieved, burst synchronization is begunby locking the receiving end into a re-peating 11 -bit code that has a duration of1.34 milliseconds, the same length as theburst of compressed data.

When the bursts are locked into eachother, full duplex transmission of actualdata begins. Synchronization is con -

(Continued on page 100)

Voice and data capability istested with a special set.

I

onininnanom= *numninssonsinn n

TAKES THE LEADIts speed and low power consumption spark the new

generation of lap -size portables

BY GENE PATTERSON & JIM MAGOS

ANEW age is dawning in semiconductor technology thathas far-reaching implications for the entire electronicsindustry. At the forefront of the dawning age is CMOS

(complementary -symmetry metal -oxide semiconductor) tech-nology, which promises to fill the needs of equipment designerswith devices ranging from the very simple to the ultra -complex.It has been estimated that, by 1990, at least $15 billion of theprojected woldwide IC market of $40 billion will be for CMOSdevices.

Ever since their development at RCA's David Sarnoff Re-search Laboratories in Princeton, NJ in the early 1960s, CMOSdevices have steadily moved to the forefront of digital and linearIC technologies.

Today, almost every semiconductor manufacturer carries aline of CMOS devices, with some firms developing greatly im-proved versions' Originally conceived as a gate -level, logic -de-vice family, CMOS technology, and its offsprings, now span thefull range of digital circuitry from microprocessors and memo-ry chips to the semicustom gate -array and standard -cell devicesthat figure prominently in the emerging very -large-scale inte-gration (VLSI) technology. (See "The Incredible Shrinking Cir-cuits," C&E, April 1984.)

The use of CMOS is also growing in such linear circuits asoperational amplifiers and analog -to -digital (A/D) convertersand is fast becoming a key technology for the emerging telecom-munications and data communications markets. In light of itswide acceptability, most knowledgeable observers expectCMOS to become the dominant technology as we move towardthe twenty-first century.

Some BackgroundCMOS is one of three types of semiconductor technology

that use MOSFETs (metal -oxide field-effect transistors). Theother two are PMOS (p -channel MOS) and NMOS (n -channelMOS). However CMOS technology is unique in that it com-bines both PMOS and NMOS transistors on a single chip. Theprincipal advantage of doing this is that it yields a device thatconsumes substantially less power than any other form of ICsemiconductor.

In both structure and performance, all MOS devices dramati-cally differ from the transistors used in bipolar devices, the oth-er major type of IC technology. Bipolar technology was madefamous by the popular transistor -transistor logic (TTL) familyof ICs.

Although both bipolar and MOS transistors can be describedideally as switches, their operating characteristics are exactlyopposite. While the bipolar transistor is a current -controlledswitch that has a low input impedance, a MOS transistor is avoltage-coltrolled switch having a high input impedance. (In-terestingly, the MOS switch is much like the old-fashioned vac-uum -tube switch, which also was voltage controlled and hadhigh input impedance.)

Bipolar technology offers two distinct advantages over otherIC technologies-it can handle high current and operate at highclock speed. On the negative side, however, it also consumeshigh power, requiring heftier and more expensive power sup-plies and, frequently, expensive cooling fans or blowers.Though CMOS devices operate at slower speeds than bipolardevices, they make up for this deficiency by being almost per-fectly suited for basic logic devices right on up through the ul-tra -dense circuitry required by VLSI circuits. (To understandhow basic CMOS devices operate and are constructed, see the"CMOS Top to Bottom" sidebar.)

Because of its high power consumption, hence chip heating,

At left is a silicon wafer contain7ng 220 micncomputer 1805IC's (courtesy RCA). Incompleie squares are for wafer alignment.

PHCTO BY PETER ANGELO SIMON

September 1984 71

CMOS chips, shown above are, leftto right, a Motorola logic wit, an

RCA CDP 1805A microprocessor,and an Intel 51C4 RAM chip.

bipolar logic isunsuited to VLSI designs.

These fundamental differences ac-count for the diverse roles played by thetwo types of technology in the world ofdigital and linear ICs.

The ultra -lowpower consumption and ele-

ment density of CMOStranslates into a num-

ber of benefits for users, aslisted in Tables I and II. One im-

mediate benefit is reduced circuitry de-sign cost.

If an IC technology's power demandis very low, as in the case of CMOS, de-signers need less expensive and less so-phisticated power supplies and limitedor no cooling devices.

CMOS TOP TO BOTTOMFROM the most complex micropro-

cessor circuits to the simplestgates, deep within all CMOS de-

vices is a basic circuit element called aninverter. As shown in Fig. A, a CMOSinverter is composed of a p -channelMOS transistor and an n -channel tran-sistor on the bottom. Because n- and p -channel transistors have diffusions ofopposite polarity dopings, they operatewith voltages of different polarity. Thus.a positive input voltage turns on an n -channel device but turns off a p -channeldevice. Conversely, a zero voltage(ground in Fig. A) at the input to the in-verter turns on the p -channel transistoron the top and turns off the n -transistoron the bottom. Note at the bottom ofFig. A that both transistors can be repre-sented as switches to simplify explana-tion of the device's operation.

This simple CMOS circuit performsthe most basic of logic functions in a dig-ital system-that of inversion. (An in-verter is sometimes called a NOT gate,which is derived from the fact that whatappears at its output is not what is ap-plied to its input. That is, if a logic 1 isapplied to its input, the output is then alogic 0).

If the voltage applied to the input ter-minal of the inverter in Fig. A is positive,the p -channel switch turns off and dis-connects the output terminal from thepositive supply voltage. The output ter-minal is, therefore, at ground potential

72

because the n -channel switch is turnedon and connected to ground. Now, if thevoltage at the input is zero, the p -chan-nel switch turns on and connects the out-put terminal to the positive supply line.This time, the n -channel switch turnsoff.

In an actual CMOS IC, p- and n -chan-nel transistors are fabricated on a siliconsubstrate, as shown in Fig. B. The keyterminal of either transistor is the gate.In the original CMOS technology, the

Fig. A. CMOS kwerter operation.

V

DD

p-MOSTRANSISTr

n-MOSTRANSISTOR

CMOS INVERTER

p OFF

P -

n = ON n OFf-

LOIN -I-_INVERTER OPERATION

gate was made of metal. The gate formedone plate of a capacitor, whose otherplate was the substrate of the device. Thetwo plates were separated by silicon di-oxide (Si02), an insulating material. Be-cause the gate input is a capacitor, the in-put current is extremely low (fordescriptive purposes, it can be assumedto be zero).

When the output of one CMOS invert-er drives the capacitive input of anotherinverter, no resistive (IR) voltage dropoccurs in the drain circuit as a result ofthe almost nonexistent input current.Therefore, the output voltages can riseor fall to their full positive or negativelevels (power -supply positive orground). Moreover, since one transistoris on and the other is off, the net currentin the drain circuit, called quiescent cur-rent, is extremely low and is typically inthe nanoampere (10') range. For thisreason, CMOS devices consume the leastpower of any semiconductor technology.

Another observation that can be madefrom Fig. A and the operating descrip-tion given above is that this operationcan occur over a wide power supplyrange. Also, the ideal switching voltageis 50% of the positive supply voltage.That is, a 1.5 -volt switching level forVDD = 3 volts and a 9 -volt switchinglevel for VDD = 18 volts. Over a tem-perature range of -55° to + 125° C, thisswitching voltage varies less than ±1%of the supply voltage.

Computers & Electronics

When low operating power is com-bined with high -density, multi -purposeCMOS ICs, the savings come in the formof less costly support components andraw materials consumption, which re-sults in minimized "real estate" requiredfor the circuitry.

Dramatically reducing the physicalsize of a product and providing the mi-

100

"".

1 I H2 84 8t,

YEAR

Fig. 1. Expected use of MOStechnologies through 1990.

nuscule amount of power a circuit de-mands, with a lightweight battery pack,make possible sophisticated portableproducts. In fact, CMOS is the onlytechnology considered by designers ofsuch products as the latest crop of trueportable, lapsize personal computers.

The second advantage of CMOS is itswide operating voltage range. One typi-cal CMOS (the 4000 series) family, forexample, can operate at supply poten-tials ranging from a low of 3 to as high as18 volts. With this broad range of opera-tion, voltage regulation is rarely a neces-sity and long battery life can be expected.

In contrast, most TTL devices arelimited to operation at 5 volts, whichmust be regulated to within +0.25 voltand requires expensive high -current andwell -regulated power supplies.

Another parameter that favors CMOSover TTL is its switching level stabilityover wide temperature ranges. As shownin Table I, the common and inexpensive

Making CMOS chips at Motorola.

plastic -packaged CMOS IC is designedto operate at temperatures ranging from-40° to +85° C, which fills the needs ofmost industrial and consumer applica-tions. The more expensive ceramic -packaged CMOS devices are designedfor more rigorous conditions, being ableto operate over the full military tempera-ture range from - 50° to + 125° C.

The advantage of using even plastic -packaged CMOS, instead of other typesof ICs, can readily be appreciated when

METAL INT EHCONNECTS METAL INTERCONNECTS

OXIDE

p -WELL

n-MOSTRANSISTOR

ItFtl. TIP.-

GATE OXIDE -

p-MOS

OXIDE

n -SUBSTRATE

Fig. B. Both p- and n -channel transistors are on one substrate.

Processing BreakthroughSome years ago, a significant process-

ing breakthrough occurred in MOS tech-nology that had far-reaching conse-quences. This was the development of thesilicon gate as a replacement for the met-al gate. In silicon -gate technology, a con-ducting form of silicon serves as the gatematerial instead of metal. The silicongate both improved the performance ofCMOS devices and allowed the gate to beformed before the drain and source werediffused (Fig. C). In this process, a pat-terned polysilicon material is used to de-fine the gate area so that the followingsource and drain diffusions are self -aligned to the gate. This arrangement sig-nificantly reduces gate -to -drain capaci-tance as well as chip size. The process,called self -aligned silicon gate, is nowstandard in all CMOS digital devices.

Among the advantages of the self -aligned silicon -gate process, comparedto metal -gate, are lower operating powerconsumption, greater speed, higher den-

sity, and lower operating voltages. Sili-con -gate MOS devices are characterizedby low power consumption and highdensity. By contrast, bipolar TTL de-vices are characterized by low densityand high operating power. Silicon -gateCMOS devices now have the speed ofLSTTL devices. Newer, smaller -geome-try TTL families are available with high-er speed, but less power than already rel-

high -power LSTTL devices.Not content to stand still, manufac-

turers have forged ahead in processingtechnology with the development of self -aligned silicon -gate CMOS on a sap-phire- i nsu la t ed substrate. CalledCMOS/SOS (CMOS/silicon-on-sap-phire), the process yields the highest -fre-quency MOS circuits. In the fabricationtechnique, a thin film of heteroepitaxialsilicon is deposited on a sapphire sub-strate. High-speed devices are possiblebecause the process eliminates many ofthe parasitic capacitances of convention-al structures. Distributed parasitic ca-pacitance causes frequency limitations.

In addition to high speed, CMOS/SOS ICs have the highest resistance tonuclear radiation. This makes them thepreferred technology for use in aero-space and certain military systems. 0

Fig. C. The silicon gate improved the performance of the CMOS.

ME 1 At

SILICON'OVERCOAT"

GLASS

s102

SOURCE DRAIN FIELDp+ P+ IMPLANT

n -SUBSTRATE

-oral p -WELL

META_

GLAS&_

September 1984 73

!NM INTRODUCES FIRST CMOS RAMS BY LES SOLOMON

BEC AUSE of its very low power re-quirements, Complementary Met -II Oxide Semiconductor (CMOS)

technology is the key ingredient in theproduction of battery powered, truly por-table computers.

The first use of CMOS was in RAMapplications that could provide nonvola-tile battery backed -up memory systems.Such systems have the ability to main-tain data even if they lose external powerfor an extended period of time. Also, the

low standby power requirement allowedthese systems to maintain data for longperiods of time even when powered fromrelatively low -power batteries.

However, there was a payment.The "horsepower" of these systems is

measured by the "speed -power prod-uct", a combination of gate delay (howfast the chip operates) and power dissi-pation (standby and active). Althoughthe power requirements of CMOS is farless than that for TTL, CMOS was much

slower (it has a poor speed -powerproduct).

However, computer designers decidedthat the low power requirements out-weighed the somewhat slower speed, sothey elected to use CMOS in their porta-ble computers.

In the search for low power, yet fasterelements, several improved variations ofCMOS were introduced. Among theseare HMOS and NMOS which have beenused in CPU chips.

one considers that NMOS, PMOS, andbipolar devices are usually rated for op-eration between 0° and +70° C. This re-striction puts non-CMOS devices undera definite handicap in certain extended -temperature -range applications, such asthe abusive under -the -hood environ-ment where many automobile enginecontrols are located. Here, CMOS is fa-vored because its stable temperaturecharacteristics can withstand the widefluctuations that are normally experi-enced under a wide range of conditions.Other wide -temperature -range applica-tions that fall into CMOS's domain arein space, military, consumer, and indus-trial systems that require very stable op-eration over a wide temperature range.

Still another characteristic that ele-vates CMOS above the other IC technol-ogies is its high immunity to electricaldisturbances, commonly known as"noise," generated within a system or in-duced from external sources. Digital ICspecifications generally list noise -immu-nity voltage and noise margin for eachdevice.

Noise -immunity voltage, either a logichigh or a logic low, is a noise voltage thatat any one input to a logic device doesnot cause a false signal to propagatethrough the system. The noise margin isthe difference between the specified in-

put voltage of a device and its specifiedoutput voltage.

CMOS provides the highest noise im-munity or noise margin of any currentlogic family. By contrast, TTL offers alogic 0 (VIL MAX) of only 0.8 volt and anoutput potential of 0.4 volt (Vol.Thus, noise margin is only 0.4 volt, com-pared with 1.45 volts for CMOS. Conse-quently, outside noise is more likely toaffect TTL's operation than CMOS's.

Furthermore, CMOS logic operatingat 15 V has a specified 5 V of both high -and low-level noise immunity. Becauseof its greater immunity to noise, CMOScan serve in applications associated withhigh levels of electrical noise, such as infactories where heavy machinery is usedand in cars where the ignition solenoidsand other devices generate high-energynoise.

CMOS in PerspectiveWith its multiplicity of technical ad-

vantages over other semiconductor tech-nologies, CMOS is already becoming thedominant IC technology, especially fordigital circuits.

Illustrated in Fig. 1 is the expected useof MOS technologies through the end ofthis decade. Projections indicate thatCMOS will experience the most dramat-ic growth of all such technologies. By

30

2

10

5

3

2

rAL

FASTAS

10 KH Er:

0.001 0 1 1 2 3 5 10 20

AVERAGE DC POWER DISSIPATION mW

1990, it will command about 50% of theIC market, up from about 20% atpresent.

HCMOS, a new high-speed version ofCMOS aimed primarily at logic devices,is included in the 50% total. Over thesame period, the use of NMOS will re-main about the same as it is now, whilePMOS will be on the decline as a digitaltechnology.

PMOS is the oldest of the MOS semi-conductor processes, having its origin indynamic shift registers in the late 1960sand dynamic memory devices in the ear-ly 1970s. It was comparatively easy tomanufacture but now has such majordrawbacks as: the requirement for twopower supply voltages, rather than thesingle voltage now required for all othertechnologies; it is slow; it is very tem-perature limited; and it consumes appre-ciable power, compared to CMOS.

During the early 1970s, the more diffi-cult to fabricate NMOS appeared on thescene just in time to catch the phenome-nal growth of microprocessors andmemory devices.

The major advantage of NMOS overPMOS is that its current carriers areelectrons rather than holes. This is sig-nificant because the greater mobility ofelectrons means that the same -sizeNMOS transistor is two to three times

Fig. 2. (Left) Power dissipation of different types.

Fig. 3. (Below) Evolution of the CDP 1800 CMOS.

1804A5 MHz C

2K ROM/84 RAMTIMER/CNTR

1802A5 MHz .P

11.1111114111111111805AMHz P

TIMER/CNIH

',64 RAM

1606A5 MHz P

TIMER/CNTHS

I__74 Computers & Electronics

Now, Intel has introduced CHMOS`(Complementary High performanceMetal Oxide Semiconductor) whosespeed -power product represents a six-fold improvement over their HMOS IIItechnology, and a 25 -fold improvementover HMOS technology used in 1977.

Currently, Intel is using this new tech-nology in its 51C256H and 51C256L dy-namic RAM chips capable of storing256K x 1 bits of data. These devices are pincompatible with the recently introduced

64K CHMOS and HMOS DRAMS.The 51C256H features a Ripplemode

cycle time of 65 nanoseconds, has a 120 -nanosecond access time, and is designedfor high -bandwidth applications such asgraphic displays. Ripplemode providesthe ability to randomly read or write up to512 bits within a single row in oneaccess. The 51C256L, also using Ripple -mode, has an ass time of 150 nanosec-onds and requires only 230 microamperesfor data retention, making this chip ideal

for portable computers.Because of the high cell capacitance of

CHMOS, soft errors are essentially elimi-nated. For example, these DRAMs areclaimed to be over 100 times more resis-tant to soft errors than existing HMOS orNMOS 64K dynamic RAMs.

Since it is possible to access these chipsat over 15 million bits per second, thismakes the CHMOS DRAMs compatiblewith high-performance CPUs such as theIntel iAP286 operating at 8MHz. 0

faster than its PMOS counterpart.Looked at another way, for a particularspeed, an NMOS transistor is smallerthan the PMOS version; hence, NMOSchips are smaller. NMOS also runs atlower threshold (turn -on) voltages andcan operate from a single + 5 -volt sup-ply, making it compatible with other log-ic technologies.

As a result of its advantages overPMOS, NMOS became, and still is, theleading technology for the fabrication ofmicroprocessors, memory chips, andVLSI in general.

Interestingly, however, neither NMOSnor PMOS was much of a factor in logic"family" ICs (inverters, gates, flip-flops,counters) and other devices classified assmall-scale integration (SSI). This vastarena was dominated by TTL bipolartechnology. When the competition camefrom CMOS, the two logic semiconduc-tor technologies split off into differentapplications areas, with TTL being usedfor high-speed computers and CMOS be-ing used for most other applications.

Computers have been, and will con-tinue to be, not only the fastest growingmarket in the electronics industry, butthe major consumer of ICs as well.Though CMOS logic is used in computersystems, its current strength is in periph-erals in which its slower operating speedcan be tolerated. However, there are acouple of CMOS limitations that re-main. The worst, called "latchup," isdue to the smaller and smaller geome-tries used in the dense chips. New depo-sition techniques appear to be solvingthis problem.

Current ActivityDramatic changes are now occurring

in the semiconductor industry, includ-ing the reversal of the traditional roles ofdigital technologies. One of the most far-reaching is the emergence of a new classof very low power CMOS logic that runsat the same clock speed as the popularLSTTL (nonsaturating low -powerSchottky TTL).

The speed/power characteristics of

Fig. 4. Density and access time for staticRAM, of NMOS and CMOS.

the major semiconductor technologiesused in logic devices are plotted in Fig. 2.Note that the new high-speed CMOSfamily is about 10 times faster than itsconventional CMOS predecessor and isjust as fast as LSTTL. While bothCMOS and LSTTL operate at the samespeed (typically 9 -nanosecond averagepropagation delay time), the differencein quiescent power dissipation over-whelmingly favors CMOS.

As shown in Fig. 2, dc power dissipa-tion for CMOS is barely measurable onthe power scale, while for LSTTL it isabout 1.5 milliwatts. Generally, then,CMOS dissipates about 0.1% the quies-cent power of LSTTL logic.

The arrival of fast CMOS has greatsignificance to circuit designers. Itmakes possible, for the first time, bipo-

Gene Patterson and James L. Magos arestaff members of the Solid State Divisionof RCA.

(Continued on page 108)

500

200 -

100 -

50 -

74 7'6 78 80

YEAR

B

8482

September 1984 75

Xerox PARC-Heroes of the micro revolution

A look at the think tank where many feel it all began

BY MARTIN PORTERWHEN Apple introduced its

Macintosh last winter, memo-ries were stirred in scientists

who have seen the personal computergrow up over the past ten years.

While the press extolled Mac'sinnovations-its mouse, high -resolutiongraphics, icons-the unit is actuallyreminiscent of a machine that predatespersonal computing altogether, theAlto. Although the Alto was not as per-sonal as today's products in size or cost,it was a prototype for distributed pro-cessing. It also set the stage for such sub-sequent innovations as the local area net-work (LAN), laser printing, Smalltalk (acombination of a programming languageand a graphics package), bitmap displayand overlapping windows.

Alto and these corollary features orig-inated where many other of today's lead-ing -edge technologies have their roots:Xerox PARC. It is no suprise that theXerox Palo Alto Research Center has an

aura of almost Olympian proportions inthe microcomputer industry.

The numerous features that originat-ed there are now widely exploited in themarketplace by firms like Apple andMicrosoft, where outstanding Xeroxalumni migrated as they scatteredthroughout the industry. Other PARCscientists are making their marks else-where as well: Convergent Technol-ogies, 3Com, GRiD and DEC. Eventhough VisiCalc co-author Dan Bricklinnever worked there, he commented thatPARC is a national human resource. Hisstatement is often repeated these days,even by Xerox executives who make sureyou know they are only joking.

Today, however, Xerox isn't eager totalk about its premiere R&D facility

Martin Porter is a contributing editor ofPC magazine. He writes frequently aboutelectronics for several publications.

whose past is so much more celebratedthan its present. Talking about the pastisn't popular at any facility in an indus-try where last year already seems like theBronze Age.

The Golden Age of PARCThe personal computer business of

1984 was very much in gear at PARC tenyears ago.The golden age of PARC oc-curred from 1971 to 1976. Then Xerox,fat from a decade of enormous growthand profits, gave the youngest and mosttalented computer scientists in the worlda blank check and an opportunity to de-fine the paperless office of the future.The Mansfield amendment in 1969 haddried up all nonmilitary Department ofDefense money, pinching tight researchprograms at universities. An indepen-dent lab like PARC could only benefit.It became known as the best computerscience department in the United States.

Bob Taylor is given credit for assem-

76 Computers & Electronics

bling the staff at the computer sciencelab. He had been the administrator of thePentagon's Advanced Research ProjectsAgency (ARPA), the U.S. space agencythat preceded NASA. He is rememberedas the man with the money at ARPA inthe 1960s, when some argue the truegolden age of computing occurred. AtPARC he collected people the way aconnoisseur might collect Tiffany glass.While he couldn't print money, he wasable to offer creative freedom withoutpressure: no rush to get a product tomarket, no need to teach classes of un-dergraduates, no push to politic fortenure.

Taylor hand-picked the entire team.Smalltalk author Alan Kay recalls thatthe hiring period for any new employeetook days and involved extensive evalua-tion of what that person could add. "Ev-ery new person was a celebration," he re-members. In fact, it was a commonplacein the industry that out of the top 100PhDs in computer science in the countryeach year, General Motors got the most,followed by Bell Labs, but Xerox PARC

Charles Simonyi wrote theBravo editor while at PARC.

got the 10 best.PARC was guided by Taylor's idea

that a think tank needed to be more a fer-tile medium and less an institution. Itwas mainly a matter of getting good peo-ple in and leaving them alone, accordingto PARC alumnus Alan Kay. "You justhad to mix together the right combina-tion of minds, and the result would bescientific dynamite."

Kay remembers Xerox P 4RC in theearly 1970s as a place populated by wild -eyed scientists in their twenties. Theywere left to "follow their noses" withouta marketing executive looking over theirshoulders. They spent hours ruminatingabout the future in a lounge scatteredwith bean bag chairs and sought pro -

Alan Kay conceived of Dynabook,the forerunner of Alto.

gramming inspiration in the middle ofthe night from the video game precursor,Space War. "There was simply nothingwe couldn't do," he recalls.

According to Larry Tesler, a PARCalumnus who went to work at Apple in1980, "The main thing driving PARCwas the realization that in 10 or 25 yearsyou would be able to get a lot of powetinto a low-cost product." Taylor and hisstaff also realized that personal comput-ing, not time-sharing or data processing,was the wave of the future.

According to Charles Simonyi, now atMicrosoft but at PARC the author of theBravo editor, the dream that was real-ized at PARC was that humans wouldbe able to communicate with computersthrough graphics rather than throughtext, simply by pointing.

Communicating with computers inthe most "human" way was what ledmany of the researchers to consider theirAlto stations more as personal secretar-ies than as personal computers. As an in-joke some signed their memos "B. A.Ear," a name formed from the initials forBravo and Alto and the code name Earof the PARC laser printer. In fact, theelusive B.A. Ear has been credited inuniversity dissertations on the work ofPARC.

Enter AltoAt a summer ARPA symposium Kay

first conceived of Dynabook. the long-term project that bore as a first fruit,Alto. Kay had seen one of the first plas-ma panels at a lab at the University of Il-linois. When he joined PARC that imagebecame a prototype for a lap -size com-puter, very much like the popular TRS-80 Model 100, but even more like a Con-vergent Technology Workslate with abigger screen. The dream machine couldgo on line, could store several million

characters, and had a touch -sensitivescreen. It would come bundled withword processing, Smalltalk and even avideo game or two.

Alto appeared then as an interimDynabook. There had been previous at-tempts at building personal computersas early as the the 1960s at MIT's Lin-coln Labs. What set Alto apart from ear-ly attempts was the emphasis its design-ers put on communication with thesilicon beast and on developing itssoftware.

The story of how the Alto was finallyput together varies, depending on whomyou talk to. The two most common sto-ries, though, incorporate a bit of anti-es-tablishment defiance: Either it wasbuilt-in three months in the spring of1973-to disprove a research manager'sstatement that it couldn't be done or itwas bootlegged against his wishes whilehe was out of town. Either way, the Altowas never designed as a marketable item,but as a prototype upon which the scien-tists could test out their software andhardware ideas. Even after several thou-sand machines were built and installedthroughout PARC, at other Xerox facil-ities, and then in offices of the FederalGovernment, the machine remained outof production.

The basic system of the original Altoincluded a video display and a three -but-ton mouse in addition to a standard key-board and finger keyset, 2.5M byte disk,Ethernet interface, and 64K 16 -bit semi-conductor memory expandable to 256K.It looked like a sleek and contemporaryworkstation with a dishwasher -sizedCPU built under its counter. It wasn'tquite Alan Kay's Dynabook, but it was astart.

The PARC LegacyFor Xerox the most important out -

Larry Tesler left PARC to goto Apple and direct the Lisa Project.

September 1984 77

Xerox PARC

come of PARC was laser printing: It hasalready become a business bringing in$250 million a year for the company. It isexpected to grow further with a new gen-eration of low-cost laser printers nextyear. For the computer industry, howev-er, PARC was a source of new products,ideas and inspiration. Dan Bricklin re-calls, "a lot of people were turned on bythat place even if they never workedthere."

Bringing new technology to real lifewas never

the aim of the researchers at PARC. Infact, in the pursuit of marketplace reali-ties several of the more prominentPARC alumni left to start businesses oftheir own or join more product -orientedcompanies. In their new settings they re-alized, in products and markets, poten-tials of ideas that had germinated atPARC.

Bob Metcalfe, the inventor of Ether-net, for instance, founded 3Com Corpo-ration, which supplies Ethernet localarea networks for IBM PCs and compat-ible computers, after he left PARC in

1980. Ethernet, which is one of 250 sys-tems licensed from Xerox, transports in-formation in "packets" along coaxialcable.

Establishing some sort of networkwith the Alto had been one of the earliestdesign aims of the PARC research team.Communication among computers forresource sharing was advanced byARPA, in fact. The Ethernet was de-signed in consort with the Alto in 1973and eventually interlinked the Altoswithin PARC and ultimatelywithin the en-

tire Xerox Corporation.Today Ethernet is generally agreed to

be the industry standard for local areanetworks. The use of LAN is becomingan established business startegy, withcompanies as diverse as DEC and Appleusing the Ethernet standard. Ethernethas brought modest revenues to Xeroxand serves as the basis of the company'snewest Xerox team office systemsapproach.

Metcalfe's company, 3Com, though,is catching more fish in its Ethernet.3Com went public in early April with an

issue of over 2 million shares of stock. Itis now shipping about 400 new Ethernetsper month. In all it has shipped 15,000 ofthe connections since it began manufac-turing them in March 1981. Most recent-ly 3Com announced it will be the suppli-er of hardware to go into a XeroxEthernet for the IBM PC and itscompatibles.

One of Metcalfe's classmates, JohnEllenby, also went from PARC to amore commercially oriented company.Now he is in charge of GRiD's Com-pass, an $8000 high performance lapcomputer; at PARC he had been incharge of taking Alto II to the buyer. Atest market of the plan was nixed by Xe-rox corporate in favor of the Xerox Starin 1980. The Star utilized Alto ideas, par-ticularly icons, but has so far been a mar-ketplace dud. Although Ellenby, likemany, maintains that Xerox probablymissed the boat in several product areas,he feels that the public underestimatesthe contribution that laser printing hashad on the company. "Xerox was pio-neering a whole new business. The factthat they didn't know it themselves israther sad."

Larry Tesler left PARC to work forApple in 1980. There he directed the Lisaproject, which brought to fruition muchof his work at PARC. At PARC he haddevoted his main efforts to makingSmalltalk a productive programming en-vironment, as well as to improving suchuser interfaces as the mouse (which wasnot developed at PARC but by DougEngelbart at Stanford Research Insti-tute), and to making the use of graphics,icons and menus more convenient. Thebitmap display, which Tesler has devel-oped at Apple, coordinates every screendot from a single chip and offers in-creased control and definitions. "It wassomething whose value Xerox PARCdemonstrated on a relatively inexpensivecomputer (Alto costs about $20,000)and Apple just bought it to a much low-er -priced computer (Macintosh costsabout $2500). The style of user interfacethat was developed first as Smalltalk, weimitated. That includes using a mouse,overlapping windows and a commandlanguage relatively free of modes. Laterthe Star systems came out and we bor-rowed the use of icons . . . However, a

PHOTO OF CHARLES SIMONY!BY CLYDE KELLERPHOTO OF ALAN KAY BYNEIL REICHLINEPHOTOS OF LARRY TESLERAND BOB METCALFEBY MIKE CARR

(Continued on page 110)

78 Computers & Electronics

THANKS To COMPUSERVE'SCB SIMULATOR,

"DIGITAL FOX"ACCESSED "DATA HARI"ANDPROCEEDED To AN "ALTARED" STATE.

The CB Simulator, whereCompuServe Subscribers canAccess Friends and InfluencePeople on 72 DifferentChannels.

Just pick your handle and geton line. From math to matrimony,there's always someone out therewho speaks your language. Friendsfrom all over the U.S. and Canada areat it 24 hours a day. Talking tech orjust having fun. And if you've got asecret, just use the CB Scrambler.

That'll fool the "lurkers',' those CB"see it ails" who get their kicksby watching. Or you can always usethe private talk mode for guaranteedone-to-one conversation.

The CB Simulator is just oneof CompuServe's many electroniccommunications options thatinclude a National Bulletin Board,Professional Forums and ElectronicMail. Plus, there's a world of on-lineinformation and entertainment allfor the price of a local phone callplus connect time.

You can access CompuServewith almost any computer andmodem, terminal or communicatingword processor

To receive your illustratedguide to the CompuServe InformationService and learn how to subscribe,call or contact

Circle No. 33 on Free Information Card

CompuServeConsumer Information Service. P O. Box 202125000 Arlington Centre Blvd Columbus. OH 43220

800-848-8199In Ohio call 614-457-0802

An NSF Block Company

September1984 79

TAPEBACKUPFORHARD DISKS

New products that aid in the vital backup of fixed disks

BY ED TEJA

AN DREW Seybold is worriedabout your data. It isn't safestored on a hard disk inside your

microcomputer. He and other expertswho spoke at a recent forum on "DataIssues in Microcomputer Applications"issued warnings to people and business-es. If they don't take advantage of avail-able technology to back up the datastored on hard disks onto some sort ofremovable media, they are in for a rudeawakening. And it isn't just the possibili-ty of a disk failure that you should worryabout. Once you are happy with thepromised MTBF (mean time betweenfailures) of the drive, you should beaware of still other types of failure.

According to Tallgrass Technologies

Corp. president, David Allen, with theonly copy of your data left inside the ma-chine, you are vulnerable to losing itthrough a variety of catastrophies,including:

operator neglect or error, equipment failure, disruption due to power loss or elec-

trical interference.The trend toward widespread use of

microcomputers in big business makesthe magnitude of the problem even moreserious. Joseph Duncan, an economist atDun & Bradstreet, estimates that over

Ed Teja is a free-lance technical writerwho often contributes to C&E.

70% of firms with more than 500 em-ployees have microcomputers. Over80% of these micros, Duncan says, areused by professional and technical peo-ple. If you are using a microcomputer inyour work or integrating systems forprofessional applications, you shouldlearn right now what data-processingprofessionals have often learned thehard way-the most reliable fixed -diskdrive can fail to protect your data.

Scope of the ProblemAs the smaller Winchesters (particu-

larly the 51/4" drives commonly used indesktop computers) begin to providemore and more storage for fewer dollars,the task of backup becomes increasingly

ART BY CARL WESLEY80

Computers & Electronics

difficult. Backing up a 5M -byte Win-chester disk with floppies might bereasonable; backing up a 40M -byte Win-chester with conventional floppy disk-ettes is unthinkable. Both the incredibleamount of time it would take to put 40Mbytes of data on floppies and the largenumber of diskettes required should beenough to make you search for newalternatives.

But if diskettes aren't the best backupsolution, what media can do the job?Tape, of course.

The Perfect Backup MediumThe standard choice for backup medi-

um in large computer systems has tradi-tionally been magnetic tapes. Look inany bank's or insurance company's com-puter center and you'll see that they'veinvested thousands of dollars in tapedrives. Tape drives, especially the newermodels, boast three attributes that makethem unusually attractive for backup:

I. They store large amounts of data in

Interdyne's 40 -megabyte 3' tape drive.

perform its backup chores (backing upan entire disk) in less than 15 minutes.

From a practical standpoint. the timeconstraint (less than 15 minutes to backup the disk 1 means that you'll want to re-strict your search to streaming record-ing. In streaming mode the tape drive

elr

A side view of the self -threading Interdyne drive.

a variety of convenient package sizes.2. The medium is easily interchange-

able, which makes it available for othersystems.

3. Tape isn't prone to damage (youcan mail tapes more easily thandiskettes).

Generally speaking, therefore, mag-netic tape is an ideal medium for archiv-ing essential programs and data. So whyhaven't we seen more tape systems in themicrocomputer market? Cost. Backup isan added expense. Only now that micro-computers are commonly performingbusiness and work -related tasks is thesafety of backup becoming what buyersmight consider a reasonable expense.

The Perfect Backup DeviceWhat should you expect from a tape

drive designed especially for data back-up? What are the characteristics of theperfect backup device? Ray Freeman,management consultant with a specialinterest in tape drives, asked this ques-tion of a cross section of users and con-cluded that a reasonable backup devicewould cost between one-half and one-third of the price of the disk drive and

records at high speed (typically 90 ips)without stopping between data blocks.Thus the gaps between data blocks (theinterrecord gap) can be quite small.

To a streaming tape drive, these gapsare just markers. A 13 -byte interrecordgap does the trick. There's no need toworry about stopping the drive. In start/stop drives, however, the drive does stopat the end of every block. Thus the gapshave to be large enough to allow thedrive time to stop. The interrecord gapon a typical start/stop drive has to be

960 bytes. Consequently, streamingdrives make much more efficient use ofavailable tape than start/stop drives.How much of a difference overall? Astreamer will use 97% of the tape fordata, whereas a start/stop drive record-ing 512 -byte blocks will use only 35% ofthe tape for data. The rest is overhead ofone sort or another.

If you are selecting a backup devicefor a microcomputer, you'll make yourchoice from one of three catergories:

storage subsystems, tape cartridge drives, other tape systems.

A Complete PackageThe subsystem category is the easiest

to understand, partly because someoneelse does the bulk of the work for you. Amanufacturer packages both the harddisk and some form of backup in a singlepackage. Typically, a single system com-mand instructs the subsystem to back upthe hard drive at the end of the work day.But developing subsystems for micro-computers is tricky. Although the suc-cess of a design depends a great deal onthe ultimate end -user pricetag, it must beevery hit as reliable and easy to use asthose designed for larger computer sys-tems. To produce good equipment the

Interdyne's drive usesa single -reel tape.

September 1984

INDEX

GAP1

w

REPEATED 32 TIMES (314 BYTES)

0 8 ID FIELD -ZX C SCCci) -,w,Y

IHER,R

DICICIC

ID AM

GAP- 2 M. DATA FIELD P-

o 8 C CRR

Ic; c:2 <dui 256 DATA dICDATA AM

w

tn

352X4E

NOMINAL

Fig. I. A disk format of 256 data bytes/sector.

BELT GUIDE ROLLERS (2)

TAPE SHOWN INBOT POSITION

ERASE HEAD

WRITE/READ HEADS

BELT CAPSTAN

DRIVE ROLLER

DRIVE MOTOR

DIRECTION OF TAPE

SUPPLY HUB

FLAT DRIVE BELT

TAKE-UP HUB

FILEPROTECT

SAFE SWITCH

CARTRIDGE -IN SWITCH

TAPE PATH (OXIDE OUT)

FIXED TAPE GUIDES (2)

- TAPE HOLE SENSORS

Fig. 2. Makeup of a tape cartridge.

subsystem designer has to be innovative.Tallgrass Technologies Corp. begins

putting innovation to work in a control-ler design that makes the most of what-ever disk drive is used. The firm'sHardfile technique formats the disk intrack, rather than in sectors. In a normaldisk format of 256 data bytes/sector(Fig. 1), each sector contains 58 bytesthat aren't data-these bytes (calledoverhead) are used for spacing and pro-viding information such as addressmarks. A 256 -byte sector, therefore, ac-

space in the track. Multiply this over-head times the number of sectors perdisk and the overhead penalty mountsup quickly.

A typical 51/4" Winchester disk canstore 10,416 bytes/track, but after for-matting (with 256 -byte sectors) it canstore only 8912 bytes/track. How doesthis work in practice? On a small Win-chester disk drive that furnishes 12.7Mbytes of unformatted data space, a con-ventional 512 -byte sector format pro-duces IOM bytes of storage: Tallgrass'sHardfile approach produces 12.5Mbytes of storage.

Thik, Tallgrass's subsystems giveyour system an improved ratio of cost/M byte-a conventional method of mea-suring the cost-effectiveness of compet-ing storage techniques-over many oth-er techniques without doing anythingbut looking at data storage differently.

You could, of course, create a systemthat would reap these benefits yourself.Just do what Tallgrass did. But thenyou'd have to write the software and de-velop the hardware to support thesenonstandard data structures. The point

is that the strategyhas been developed and debugged foryou. The unusual format is transparentto your computer system. To put thesesavings into a clear perspective, considerthat the firm's TG -3006 subsystem com-bines a 6M -byte hard disk and 20Mbytes of cartridge drive storage for a re-tail price of $2995. An interface package,including interface hardware (the cardplugs into any expansion slot) and soft-ware, costs $149 for an IBM PC/XT and$169 for Texas Instruments' Profession-al Computer. For more disk -intensiveapplications the firmoffers subsystems

Fig. 4. Wangtek 5000E cartridge drive.

that provide as much as 140M bytes ofhard disk and 60M bytes of tape backup($9495 retail).

Another advantage of subsystems isthat they offer a means of performingdata backup without host computer in-tervention. This means that a singlecommand can instruct the subsystem totake care of backup. A built-in buffermemory large enough to hold an entire10K disk track lets transfers take placeat high speed. And the buffer aids nor-mal system performance as well, holdingthe entiretransfers of data to the host computer.

Cartridge Drive TechnologyData subsystems are quite useful, but

they don't meet every microcomputersystem's needs. A bare tape drive canprove more effective if, for example,your system already has a hard disk andall you need is backup. Adding a tapedrive means that you can select the exacttradeoff of performance and cost.

The most popular tape drives thesedays are the 1/4" streaming cartridge

Fig. 5. Northern Tel's MTC/6109 stores 75M bytes.

82 Computers & Electronics

WRITE HEAD(TRACK 1 & 3)

READ HEAD(TRACK 1 & 3)

\ALI

r3 ----if

READ HEAD(TRACK 0 & 2)

ERASE HEAD

WRITE HEAD(TRACK 0 & 2)

Fig. 3. Read -after -write head.

tape drives. The cartridge developed by3M in the 1970s (Fig. 2) contains a me-chanical system of belts, guide rollersand capstans. Putting tape in a cartridgemakes it easy to use. Most of the drivesmake use of the industry standard DC -600 and DC -300 tape cartridges.

Today's cartridge drives can provideperformance to match your backupneeds. Archive Corp., for example, of-fers tape drives that can back up 40Mbytes of disk in eight minutes and backup 20M bytes in four minutes on 9 -tracktape. Its 4 -track models can back up20M bytes in four minutes, running at 90ips, and 12 min, running at 30 ips. Evenincluding the time to change the car-tridge, it takes only nine minutes to backup a 40M -byte disk using a 20M -byte 4 -track cartridge running at 90 ips. Be-cause the drive uses separate read andwrite heads, with the read head follow-ing the write head (Fig. 3), error check-ing can take place dynamically.

Tallgrass carries its unique views onformatting over to tape as well. Unhap-py with the proposed QIC standard (seethe box entitled "Setting Standards"),Tallgrass defined the PC/T-11 (personalcomputer tape) format, which puts 60Mbytes of storage on a standard DC -600A

REMOVABLEREEL

DRIVE PULLEY

TAPE GUIDES

DRIVE BELT

TACH DISC

IDLER PULLEYS (4) -\

./dJip TACH SENSOR

11.1.111111 I ilig2TRANSPORT BELT

71*rt111-5TAPE

TAKE-UP REELECTv

MOTOR

READ/WRITE HEAD

Fig. 6. Interdyne's device uses a self -threading system.

cartridge. This format blends start/stopand streaming formats together, provid-ing smaller interrecord gaps than typi-cally found on start/stop drives, yet fur-nishing an ID for each record. Theserecords act as markers that the drive canuse to define the location of an individ-ual record. Thus, even though you areusing the drive for high-speed backup,you can still replace individual recordson the tape. Other manufacturers-Ar-chive, Data Magnetics and Wangtek-have signed an agreement to use PC/T-11 as a standard format.

The HCD-75 Data Cartridge Systemfrom 3M's Data Recording ProductsDivision uses cartridges for both start/stop and streaming backup modes. Thislets you use the drive as more than just abackup drive. With start/stop record-ing, access to data is slower than it wouldbe with a disk drive, but it is usuallymuch quicker than access to data on astreaming drive. In harsh environments,the ruggedness of cartridge tape can out-weigh its slowness in acting as the prima-ry storage device. The drive can transferdata at 35K bps and features either aproprietary 3M interface or a SCSIcontroller.

Wangtek's enhanced 1/4" cartridge

Fig. 7. Tandon's TM951 puts 50M bytes on a reel.

drive, its Series 5000E (Fig. 4), can useeither a DC300XL (450') or DC600A(600') cartridge to store from 20 to 60Mbytes. The transport senses the type ofcartridge you've inserted and automati-cally makes the necessary adjustments,such as modifying the bias voltage tocompensate for different light transmis-

TAPE DRIVEMANUFACTURERS

Archive Corp.3540 Cadillac Ave.Costa Mesa, CA 92626

E itrepo1294 Lawrence Station Rd.Sunnyvale, CA 94086

InterDyne157 Topaz St.Milpitas, CA 95053

Irwin Magnetics2311 Green Rd.Ann Arbor. MI 48105

MemtecKeewaydin Dr.Salem, NH 03079

Northern Telecom Inc.Memory Products Div.100 Phoenix Dr.Box DAnn Arbor. MI 48106

Tallgrass Technologies Corp.11100 W. 82nd St.Overland Park, KS 66214

Tandon Corp.20320 Praire St.Chatsworth, CA 91311

3MDepartment DR83-25Box 33600St. Paul, MN 55133

Wangtek41 W. MorelandSimi Valley, CA 93065

83

sivity characteristics. The drive also po-sitions the head to the center of thetape's QIC-24 track reference burst toeliminate head -alignment problems. Theautomatic head -alignment will compen-sate for differences among machines upto 0.011".

Another drive that changes its operat-ing parameters according to the car-tridge comes from Northern Telecom.Its MTC/6109 (Fig. 5) stores 75M byteson a 600' cartridge and 45M bytes on a450' cartridge and is fully compatiblewith the 9 -track QIC-24 standard. A 12 -

track version of the drive (Model MTC/6112) can store up to 100M bytes on a600' cartridge and still read 9 -track Q1C-24 recorded tapes.

These are but a few of the drives on themarket using standard cartridges. Ifyou've got the space these drives require,you should easily be able to find one thatmeets any reasonable performance needs.

Sometimes space is the most impor-tant system resource. Small becomes notonly better, but essential. For those ap-plications, Memtec Corp. has opted touse a smaller -than -standard cassette forits 40M -byte Model 440 as well as itshalf -height Model 420 (20M bytes) andModel 410 (10M bytes). The front -load-ing cassette drives can back up 40Mbytes (Model 440) or hard disk in nineminutes. It takes four minutes to back up20M bytes of data on a 4 -track tape.

The media for 40M -byte storage is a450' 9 -track cartridge that uses 0.15"tape. The cartridges sell for $5 and areintended to last for five years (or 20,000passes).

There are only three moving parts inthe drive transport and two moving partsin the cartridge. This simplicity contrib-utes to the drive's reliability. The manu-facturer boasts a 7000 -hour MTBF. .

Irwin Magnetics puts 10M bytes on

OPTIMIZING HEAD DESIGNTALLGRASS Technology sees

weaknesses in the complexhead designs that other manu-

facturers use in their cartridge tapedrives, especially the configuration

Tallgrass's new head designis shown at the right.

found in the form of the QIC stan-dard. The standard calls for a headwith two read gaps, two write gapsand an erase gap-five gaps total. Asa result, the head is costly, and main-taining azimuth between the gapsproves difficult. Thus you'll find asimpler head, with a single gap, inTallgrass's own tape drives. The headactually overwrites a tape, ratherthan erasing it.

The three crowns of the more com-plex head, shown in the diagram, di-vide the tape tension. But the tensionin a cartridge is already quite low. Di-vided in this manner, it's rough tokeep the tape in reliable contact witheach crown. With the single crown,the problem doesn't exist.

DC -600 media, but in the smaller DC-

100A sized cartridge. The entire drivefits in the same space as a half -height51/2" floppy disk drive and interfaces toan SA450 standard floppy disk interface.The Model 110 is suitable for use intransportable computers. And Irwingoes itself one better with its Model 210.Using the same cartridge, interface andstorage density, the unit takes the spaceof a 31/2" drive.

Other Magnetic Tape AlternativesI he search !Or lower cost storage has

led to interesting solutions. At Entrepo.designers began with a smaller -than -av-erage cartridge and tied the ends of thetape together to form an endless loop.The cartridge, dubbed a Microwafer, isabout the size of a standard businesscard, but thicker.

Entrepo's Microwafer tape transportcan access data easily, yet its construc-tion requires a minimum of movingparts, which helps to keep costs down.When you insert the data cartridge intothe drive, the capstan presses throughthe tape against a rubber wheel mountedin the cartridge. When the capstan turns,it turns the wheel and pulls the tape fromthe reel.

The Microwafer drive isn't in volumeproduction yet, but the firm hopes toproduce them for under $50. Each $1.50cartridge stores up to 128K of data (a 62'tape formatted in 512 byte sectors). A10' tape cartridge could store 17K ofdata.

The search includes formats otherthan tape cartridges. One possibility is athrowback to reel-to-reel tape. Tapedrive manufacturers moved to car-tridges in the first place because of theirconvenience, but with today's technol-ogy, packaging tape in a cartridge isn't

(Conttnued on page 96)

UNLIKE most computer pe-ripheral industries, the car-tridge -tape manufacturers

have established some standards thatmake the interchange of data be-tween machines not only possible,but practical. The working group fordata cassette compatibility, D/CAS,has established several standard re-cording and interface standards thatit hopes will promote the use and ac-ceptability of cassette -tape products.

The hardware standard is calledthe QIC-02 (quarter -inch cartridge).The standard provides a minimal in -

SETTING STANDARDSterface for the drive's basic functions a precise recording format. This 9 -but still allow a great deal of variety track standard includes a referencein implementing special functions. It burst on track zero that individualworks with a majority of existing drives can use for dynamically align -controllers and provides a basis for ing the head before playing datasystem designers who don't want back. This reference burst will reducetheir products to be made obsolete by off-track errors that occur over time.improvements in backup technology. The format is group -coded recordingA system with a QIC-02 interface (GCR), which uses two 4 -bit nybblesshould prove to be a safe bet. encoded into a 5 -bit word. Each W

For those who want to ensure that shown in Fig. A denotes a 5 -bit word.data recorded on one cassette ma- Laying out the tracks in a serpen-chine can be accessed by another tine fashion (Fig. B) puts the begin-machine-perhaps in another system ning of track I at the same end of theat a later data-the QIC-24 specifies tape as the end of track 4. This allows

84 Computers & Electronics

BY ROBERT HONE

1F you have a messy desk like mineand sometimes leave your floppydisks in the clutter, you're asking for

trouble. A floppy disk left flat on a deskcan easily be pushed under a telephone,where one ring can obliterate the data onit. There are ways to considerablyreduce-or even eliminate-the hazardof lost data. Here, we'll explore the haz-ards common to floppy disks and detailsome of the steps that can prevent re-corded data from being irretrievably lostas a result of carelesness or accident.

The CausesInformation is stored on a floppy disk

as tiny magnetic charges in the oxidecoating. A disk drive changes the mag-netic fields with a small, precise electro-magnetic device, called the drive head.

Disk drive heads aren't the only de-vices that produce magnetic fields. Anyelectromagnet produces a field that canaffect the data recorded on a disk. Typi-cal examples include the deflection sys-tem in a TV receiver, the electromagnetthat rings the bell of a telephone, and anyelectrically driven motor. As a rule,

these electromagnets are large comparedto the disk drive head and aren't veryprecise. When a floppy disk gets tooclose to them, say, within six inches, anydata on the disk is either erased or ren-dered useless.

Data on a floppy disk can also be lostthrough contamination of the recordingmedium by dust, fingerprints, smoke,and other foreign matter. A typical dustor smoke particle can render many bytesof data useless by blocking the drivehead when an attempt is made to readthat portion of the disk and can perma-nently damage the disk medium andhead with scratches. Likewise, oil on fin-gers can interfere with the reading ofdata by placing a film on the mediumthat can prevent the drive head frommaking contact with the recorded sur-face. To protect against such contamina-tion, floppy disks have inner woven lin-ings that are designed to pick up dustand oil. Additionally, most of the sensi-tive medium itself is covered by plastic,with only small selected areas showingthrough.

Heat is yet another hazard for floppydisks. It doesn't take much heat to de-

stroy a disk. As little as 120° F can seri-ously warp the Mylar material on whichthe oxide is deposited and which con-tains the recorded data. Therefore, don'tleave floppy disks by a window, on a ra-diator, in a car, or near any other heat -generating device-period!

Disk StorageThe simplest way to store floppy disks

is in the cardboard boxes in which theycame. Doing so, however, can eventuallylead to just the kind of problem you wishto avoid. Opening and closing the box fa-tigues the cardboard, which breaks downinto a fine paper dust that can easily con-taminate any disks stored in the box.

Much better approaches to storingfloppy disks can be had with other stor-age devices. For $10 or less, you can ob-tain a plastic diskette filing box that re-duces the possibility of contamination bydust and other airborne particulants.These boxes each hold about 20 diskettesand usually have dividers. They're avail-able in a wide range of colors, whichhelps in organizing your disks accordingto software type.

(Continued on page 96)

the drive to continue reading or writ-ing data without waiting for a costlytape rewind.

The D/CAS group has also intro-duced a variation of the QIC-24 stan-dard, called D/CAS-6. It defines a 4 -track tape, preferred by some 1/4°cartridge tape users. This standardhas been submitted to the AmericanNational Standards Institute for con-sideration as a standard.

For more information on the QICstandards or D/CAS group, contactFreeman Associates, 311 E. CarrilloSt., Santa Barbara, CA. 0

EOT

Figs. A & B. Layout of the QIC-24 standard system.

Firo71

1w1w1

[PREAMBLE! WI

[PREAMBLE I w I

[PREAMBLEIwI

TRACK 5 IwIwTRACK 1 IwlTRAQK 7 I w I

PREAMBLE I w I TRACK 3 Iw w

TRACK 4 IwIPREAMBLEI

TRACK 0 1w (PREAMBLE I REFERENCE BURST I

TRACK 8 I w I PREAMBLE I

TRACK 2 IwIPREAMBLEIlw 1 w 1

Ewlwl TRACK 8 w !PREAMBLE ]

TRACKEOT

A -->BOT

32 N-77-

BEGIN 1

END 4

LABEL action?"TEXT 2D I MEN 3DRAN

ENGINEERING DESIGN

ON MICROSNew software and hardware give micros the power of

expensive engineering design systems

BY ALEX LEE

WHEN CAD and CAE-com-puter-aided design and com-puter -aided engineering-are

in the picture, usually minicomputers ormainframes are somewhere in the back-ground. Sophisticated workstations fordrafting and analysis ordinarily requirethe support of powerful computers.Now, however, personal computers areedging into the engineering workplaceby performing tasks ranging from draft-ing to design of integrated circuits. Infact, clever software engineers have de-signed packages for personal computers(mostly the IBM PC) that are givingthose units capabilities found until re-cently only on workstations that cost asmuch as $50,000.

In its broadest sense computer -aideddesign includes any use of computergraphics for architectural or engineeringdesign or drafting. For electronic appli-cations, like printed -circuit or IC design,computer -aided engineering is the term.Using the data derived from CAE sys-

tems in physical production is calledcomputer -aided manufacturing (CAM).

Engineers have been using CAD andCAE for years with peripheral equip-ment linked to mainframes. With thistechnology, they can create and quicklymanipulate either solid or wire -framerepresentations of objects. CAD is apowerful tool because it allows them tochange their designs interactively andimmediately see the results of theirchanges.

Of course, mainframes can supportCAD activities beyond the capacities ofPC CAD systems. Most PC CAD sys-tems can only create wire -frame figures,and those in only a few colors. GreaterCPU power and larger data storage areneeded for the megabytes of data thatmany -colored solid representations mayneed. In addition, the resolution in pixels

Alex Lee writes frequently on industrialapplications of computers.

is much lower in PC CAD than in main-frames. Moreover, engineers limited toPCs cannot analyze figures using finite-

element analysis, which can be done on amainframe. By that means they can de-fine with mesh sections individual ele-ments of a figure for stress and otherforces.

For budding architects, engineers,and drafters, however, a PC -based sys-tem is probably sufficient. Even thoughthese fledgling systems do not have allthe speed or capabilities of full-blownworkstations, for many engineeringtasks they will be adequate. Most of thesophisticated CAD functions that onlymainframes can handle are rarely uti-lized, anyway.

For CAD applications, a PC will usu-ally need 512K bytes of RAM, a harddisk, and a coprocessor. The user entersdata into these systems either with alightpen or a digitizing tablet. (Thesetwo means of data entry are common tomainframe and PC CAD systems.)

86Computers & Electronics

1 1" -

/r1.-

Of course there are differences amongthe various PC CAD systems. Some aresold as unbundled software; some asgraphics engines; some as turnkey set-ups. Applications also range from 2D to3D to IC design.

Autodesk's AutoCADAutodesk, Inc., of Mill Valley, CA,

markets its AutoCAD program for pre-cision and freehand drawing in two di-mensions for 15 different microcomput-ers and more than 30 peripherals.AutoCAD has sophisticated capacities.It can pan, zoom, copy and move ob-jects, rotate them, erase them and alsostore them. AutoCAD also has the ca-pacity to redraw quickly and repeatedlyany figure entered into the system'sdatabase in any desired rotation and x -yscaling.

The system lets the user draw points,lines, traces, arcs, circles and irregularshapes. Repetitive patterns can be gener-

In the three photos at the left, theSpace Tablet is used to draw a pulley.Thirteen digitized positions are required-one to identify the axis and 12 for thering structures with the same axis. Inthe center photo, the dimensions and textlabels are added to the drawing.At the immediate left is the plotteroutput showing top, front, and isometricviews of the pulley.

aced automatically,and text can be in-tegrated intodrawings. Lines

and tracings may be drawn to the resolu-tion of the display or plotter used. In ad-dition, the system calculates the correctending angle on each segment of a multi-ple -segment trace. Circles can be createdeither by specifying a center point andradius or by citing any three points thatlie on the circumference. Arcs, likewise,can be drawn by specifying three points.A designer can also fill in quadrilateralor triangular sections.

An ASCII drawing -interchange fileforthat permits AutoCAD drawings tobe used with other programs. As a result,drawings can be transferred to othercomputers via modem. Drawings creat-ed with AutoCAD may also be sent toprofessional CAD systems built byIntergraph Corporation in Huntsville,AL.

AutoCAD is written in the C lan-guage for systems ranging from theCP/M-80 machines having 8' floppydisks to the IBM XT. It costs $1000 for

the standard setup and $1500 for setupsthat include dimensioning, cross -hatchpattern fill, partial delete, axis com-mands for ruler lines, sketch modes, anda units command for both dimensionsand coordinates in feet and inches.

This type of software gives the user lit-tle more than line sketches. Anyone whodesires the third dimension will need tolook further.

IGC's High -Resolution GraphicsSystem

IGC, Inc., of Hauppauge, NY, is well-known for its high -resolution graphicsystems. It offers a 3D turnkey setupthat can create solid images and manipu-late them without host intervention. Thesystem costs under $30,000. It integratesthe firm's RGC-1000 high -resolutioncontroller and software from CubicompCorporation, Berkeley, CA. It uses anIBM PC with at least 512K bytes ofmemory, an Intel 8087 coprocessor, key-board, command monitor, RGC-1000display generator and a high -resolution19' monitor. Special features of the con-troller allow an operator to zoom, pan

A typical application on the Mindset computer is Caddraft-on the left is an architectural site planshowing a building and landscaping; on the right is a crass section of a ball bearing assembly.

The Perceptor interfaces to anymicro through an RS -232 port.

and window any portion of a 3D imagewithout host -computer intervention.The system also includes a 16 -bit DMAinterface that permits the PC to talk di-rectly to the display generator at 170Kwords/second.

With the Cubicomp software, a usercan create complex solid -model geome-tries, remove hidden lines and hiddensurfaces, execute smooth shading, doanti-aliasing, move the light source, clip,and insert text.

An interactive menu -driven com-mand structure makes it simple to repre-sent an object, which is displayed with aresolution of 1280 by 1024 pixels with upto 256 colors from a palette of 16.7 mil-lion available colors.

The RGC-1000 can be ordered tozoom, flip or pan the image across theviewing screen into as many as four inde-pendent windows, each of which can dis-play a portion of the image.

MicroControl System'sSpace Tablet

For some applications, three dimen-sional drawing, even in millions of col-ors. isn't enough. MicroControl Sys-tems, Inc., Vernon, CT, manufactures3D digitizing equipment that transforms

88

the IBM PC or Apple Ile into a remark-able engineering tool. Through its SpaceTablet, a mechanical 3D digitizer. andAdvanced Space Graphics software, thesystem can depict an image of a solid soexact that it can be altered, measured.and experimented on.

Like other CAD programs, this onecan scale, rotate, and move images aboutan axis, duplicate a figure. even in mirrorimage. draw arcs and circles, examine si-multaneously three orthogonal views ofan object, add text, automatically di-mension angles and lengths, and driveseveral plotters and printers. Drawingsor models can be copied by tracing phys-ical objects. Alternatively, the tablet canbe used as a 3D joystick to create imagi-nary shapes. The complete system costs$1995.

The Space Tablet has many applica-tions. A sensor or probe can be attachedto its arm to perform 3D field mapping.For example, a thermometer attached tothe tablet arm can be used to measurethe temperature of hot air generated by ahair dryer. The 3D isotherms can be pro-duced by interactively positioning thearm and recording its coordinates. Othertypes of data can also be mapped withthis method. For applications that re-

quire more rigor and more flexibility,MicroControl System's Perceptor digi-tizing arm offers 7 -mil resolution. It caninterface with any computer because itincludes a Z80 microprocessor that cansend digital data to any computer with aserial port. The system costs more thanSpace Tablet: $9500.

blindset ComputerAmong graphics engines, the Mindset

computer, from the Mindset Corpora-tion. Sunnyvale, CA, is one of the best; itsells for $2495. It is compatible with theIBM PC and has enhanced computingpower for image processing and bit -mapped color display. It relies upon theIntel 80186 microprocessor, which isaugmented by two custom microproces-sors. Mindset can support a resolution of640 by 400 pixels and can display 16 col-ors out of 512 when the resolution is re-duced to 320 by 200 pixels.

Chancellor Computer'sSymgraph/Cadgraph

For a user more interested in depict-ing schematics, printed -circuit boards,and even ICs than in creating 3D im-ages, other systems offer effective fea-tures. Though many circuits designedwith these systems have to be bread-boarded to be tested, these programs en-able engineers to set everything up andin many cases download the informationto larger CAE systems.

Chancellor Computer Corporation,Mountain View. CA. offers a completesetup for schematic and printed -circuitboard design on the IBM PC/XT. A me-dium -resolution system costs $13,500and contains a schematic editor, a net -

Drawing with the Space Tablet

,J4

ATARISOFT. All the hits your computer is missing.

It's showtime.Time for ATARISOFT- to

show you six exciting, brandnew games that are destinedfor stardom.

Games that can be played onyour Commodore 64, IBMPC and Apple II. (Some titles

available on IBM PC jr. andVIC 20'.1)

First, there's Gremlins;based on the charac-ters from the originalfilm presented bySteven Spielberg.

Then there's CrystalCastles- whereBentley Bear- journeys

through all sorts oftantalizingly difficultpaths and ramps in his

endless quest for gems.In Donkey Kong Jr' by

Nintendo,' Junior tries torescue his fatheragainst immenseodds. And speak-ing of DonkeyKong, there's alsoMario Brothers' byNintendo. This time,Mario and his brotherLuigi battle creatures onfour levels of floors, en-countering all sorts oftreacherous enemies.

In Track And Field' youcan compete by yourself or

tl

head -to -head with anotherplayer But each player mustbeat qualifying times, heightsand distances before they cancompete in each of the gruel-ling six events.

Typo .4 ttack is the muci-acclaimed,fun -filledprogram that

e

F ROM

ATARISOFT

.16

allows you to enjoy de-veloping your typingskills at any level.

And still play-ing tc the de-light .3f audiences everywhereare Pic -Man; Ms. Pac-Man:Jungle Hunt: Battlezone;"Donkey Kong; by Nintendo,Centipede- and PolePosition':

So. if you've been searchingfor ways to entertain yourCommodore, Apple or IBM,treat t to one of the bestshows in town, one of the hitsfrom ATARISOFT.

And don't forget thepopcorn.

ATARISOFT products are manufacturedby Atari, Inc. for use with various computersand video game consoles. ATARISOFTproduct: are not made, licensed or approvedby then anufacturer(s) of those computersand video game consoles.

Ti les available on IBM PC jr. are Ms.Poe -Ma 3, Centipede, Donkey Kong. MoonPatrol' t.nd Typo Attack. Available on theVIC 20 .s Typo Attack.

I. © 1984 Warner Brothers, Inc.; 2.Trademarks and C Nintendo, 1982, 1983; 3.Trademark of Konami Industry Co., Ltd.,C 1983 of Konami; 4. Trademarks of BallyMfg. Co. Sublicensed to Atari, Inc. byNamc 3 -America, Inc.; 5. Trademark and Cof Tai o America Corporation 1982; 6.Engineered and designed by NamcoLtd.. manufactured underlicenie by Atari, Inc. Trade-mart and C Namco 1982; 7.Tradcmark and C Williams1982. manufactured underliceme from WilliamsElectronics, Inc.

MARIO BROS. sziu"MI

DONKEY KONG JR. ATARI=

TRACK & FIELD ttp11;m2100e1SOFS

CRYSTAL CASTLES ATARISOFT

TYPO ATTACK MAME;ATARIS

SIX NEW HITSARE COMING

SOON TO A SCREENNEAR YOU.

O ION Alan Inc NI rights rrrd A Nkirner Communicatbors Company

CkS. No. 26 on Fro* Information Card

ALT.I.E1 cycle 54 stop ISPHIIPH12 ' RM- --11-11-11-11

READ"CSEL ' rilit

WRITE ' 1111air1,JLrDI02 'D3

ADMMOMADOR2

HiesTRI608

>NOSE H187_

SPX '76 aT S DM TyP ;Pt_

:24

aa sr- -"*.P5IP'"

- -IC'

Clockwise from top left PC Logs, Space Tablet,Cadgraph, PC Caps, PC Cards, and Symgraph.

list extractor, and also a layout editor.The Symgraph schematic editor is

used for both schematic entry and sym-bol creation. In the schematic entrymode, the package acts as a hierarchicalwiring editor that supports the represen-tation of electronic designs at multiplelevels: function, block, gate, and discretedevice. In addition, it may also be usedto draw block diagrams and flow charts.

A menu prompts the user, who selectsoptions with a mouse or digitizing tablet.The user can then create and modifymenus or choose items out of a library ofstandard logic, discrete and TTL com-ponents provided with the editor. It isalso possible to create new symbols andenter them into the database. Moreover,text can be associated with the symbolsor wires.

The software also lets the user manip-ulate the image as a 2D drawing systemdoes through commands includingCOPY, MOVE, ROTATE, PAN, and ZOOM.Information can be taken from the sche-matic editor and transferred to a net list,which is a listing of the nodes in a circuitthat must be connected by wires. The netlist extracts information for the sche-matic database and generates a bill ofmaterials. It also lists the pin connec-tions for every node.

Once the schematic is completed, the

1 4.-Z7

P,FleEC17.:,GT.E"PHI 2

. . 00 OC)

0?'

.(.1)SIALL ZE

C). rJR

..))12137 So*I.F

,..

Ica, P.m.)PET

.:RCRI_r.A.Yr

Z :PI

pFN

.,CrlCLOCT

(A.

EDI!MOUE

RDT

DEL.

CI YR

ZUUT

HU*LPN.,

'14'

engineer can use it to generate pc boardartwork through the Cadgraph docu-mentation package, which supportsboards having up to 50 layers.

A user can also define power andground planes as well as drill points, sol-der masks, and hole sizes. A library ofpredefined component patterns permitsthe generation of artwork that may be

There is a mainframequality in the

PC Logs package,which is an inter-

active logic simulator

used to create a pc board. Once the de-sign is complete, it may be output to aprinter.

Personal CAD SystemsPersonal CAD Systems, Inc., of Los

Gatos, CA, goes one step further, offer-ing packages for the IBM PC and linksfor every phase of design and even someof simulation. It includes drafting tools,which could be used by the engineer de-signing a device, and electronic pack-ages, that let the engineer work electron-

ics within or around this device.Three packages are available for elec-

tronic design: PC Caps, PC Cards, andPC Logs. Accompanying these packagesare utilities to organize and update thedatabase once changes are made to thedesign.

PC Caps is a schematic capture pack-age with many of the features of profes-sional workstations. It can help an engi-neer to lay out a circuit or check againstwiring mistakes, such as shorts or de-sign -rule errors. One helpful feature is itsability to stretch like a rubber band fas-tened at one end, when dragging a com-ponent around the screen with all itsconnections intact in real time.

PC Cards provides similar features forpc board layouts. It supports the cre-ation of multiple -layer pc boards, canbuild traces in a rat's -nest fashion, andcheck for design errors. It taps the datain the PC Caps and PC Nodes packages,which generate a net list from PC Caps,to create a finished board.

There is a "mainframe quality" in thePC Logs package, which is an interac-tive logic stimulator. As any designerknows, coming up with a design andbuilding it is only going half the way. Abreadboard prototype will always revealsuccess or failure. With PC Logs, a de -

(Continued on page 107)

90 Computers & Electronics

BEFORE YOU BUYANOTHER PIECEOF SOFTWARE

CONSULT THIS BUYER'S GUIDEelecting the programs.systems and games for

your personal computer can bean ordeal. You want the bestpackage that's compatible withyour system-at the right price!

LOOK NO FURTHER.THE OLYMPIC EDITIONOF THE CREATIVECOMPUTING 1984SOFTWARE BUYER'SGUIDE IS HERE!

The Editors of CREATIVECOMPUTING have awardedthe Olympic Gold. Silver andBronze medals to the leadingsoftware packages in the fol-lowing categories: Full -feature word

processors Home word processors Education: Pre-school, Ele-

mentary and Secondary Spreadsheets Database packages Games

Full descriptions, productreviews and screen photos ofeach award winner make thisthe definitive guide to the lead-ing software of 1984!

In addition to the OlympicRatings Guide, you'll find: A complete directory of

software products with fullprogram descriptions, sys-tem requirements andprices, PLUS

A full listing of software

manufacturers. with names.addresses. types of softwaremade and compatible hard-ware for each product!If you own an Apple. Atari,

Commodore 64. TRS-80 ColorComputer. or any IBM PC, andyou're in the market for newbusiness, educational. personalproductivity, recreational andutility programs, take the ordealout of shopping...save moneyand get the best package foryour system at the best price!

Order your copy of theCREATIVE COMPUTING1984 SOFTWAREBUYER'S GUIDE today!Also available at your local news-stand and computer store.

Creative Computing 1984

SOFTWARE BUYER'S GUIDECN 1914. Morristown. NJ 07960 NZ6F

YES &BUh

I'm enclosing $4.95 ($3.95* plus $1 postageyanEdRli,nsg) fi jorIpthEe .1(9084utSsOideFTUWSA

$6.)A11E

Mr., Mrs./Msp.m!

Address

City/State/ZipResidents of CA. NJ and NY State add applicable sales tax.

ION

Epson PX-8(Continued from page 38)

displayed upon startup. In addition tothe files shown in Fig. 1, CP/M on thePX-8 has a number of built-in com-mands, namely: Dir, Era, Ren, Save,Type and User.

The PX-8 operating system is dividedinto 11 modules-some are part ofCP/M and others supplement it. A list-ing of the modules with explanations ap-pears in Table I. Some noteworthy onesare the Password module and the Clockmodule. The Password module givesyour system a measure of protectionagainst unauthorized use. You choose apassword and assign it to the system.Upon startup, "Password" appears onthe screen display and you must enterthe correct password to proceed further.With the Clock module, you can set theinternal clock to either sound an alarmor turn on the system at a specified time.

The language that comes standardwith the PX-8, on ROM capsule, is anEpson enhanced version of MicrosoftBASIC. Enhancements include a power-ful screen editor, graphics statements totake advantage of the 480 x 64 display,and statements to select various screenoperating modes, to support the PX-8'sRS -232 port, to operate the micro -cassette drive in the same way as a diskdrive, and to allow control of the PX-8power supply.

Applications SoftwareFor those who want to use the PX-8

for other than programming, there aretwo ROM module programs fromMicroPro called Portable WordStar andPortable Calc/Scheduler. The modulescontain "full-blown" word processingand financial modeling software. Al-though the small screen size puts somelimits on program possibilities, as muchpower is available on the PX-8 as oncomparable desk -top systems.

Although WordStar is in ROM and

Specifications

Product: PX -8Manufacturer: Epson America, Inc.

3415 Kashiwa St.Torrence, CA

Dimensions: 11.7"W y 8.5"D X1.9"H

Weight: 5 lbOperating System: CP/M 2.2Suggested Retail Price: $995Features: 8 line x 80 character LCD,

microcassette tape, 32KROM, 64K RAM, MicrosoftBASIC, Portable WordStar,Portable Calc/Scheduler

ROM modules for the PX-8 can be insertedand removed by the user.

you may use it with a RAM disk, itdoesn't appear significantly faster thandisk -based versions of the product.There are some enhancements in thePX-8 version of WordStar, but some ofthe usual features are missing, amongthem, the help menus, file directory, re-naming function, and soft hyphen entry.Additionally, MailMerge, SpellStar, andStarIndex are not available with Porta-ble WordStar. However, there are waysof circumventing many of these deficien-cies. For example, you can call up direc-tories and rename files in the operatingsystem. Also, Portable WordStar'sOpening Menu includes two optionscalled Transmit and Reeeive that enableyou to transmit and receive files to andfrom a desktop unit running standardWordStar.

Using WordStar on the PX-8 will takesome getting used to, even for those ex-perienced with the product. One differ-ence is due to the auto -repeat feature andtype -ahead buffer of the keyboard. Ifyou hold down a cursor key to move thecursor, you'll very likely overshoot yourmark, since the cursor keeps travelingafter you release the key. Another differ-ence involves screen scrolling. New linesscroll onto the screen one character at atime (similar to the way text scrolls ontoa terminal), which is not the case withstandard WordStar. Though both char-acteristics result from features of the sys-

tem and not the software, they will be ev-ident when you use WordStar and areprocessing large amounts of text.

Portable Cale and Portable Schedulerare available together on one kOM cap-sule. Portable Calc displays six rows andeight columns of a worksheet of 256rows by 64 columns. Although we didnot give the program a vigorous work-out, it appears to compare well with sim-ilar programs found on desktop systems.

Portable Scheduler uses the PX-8'sbuilt-in clock and tone generator to pro-vide calendar and alarm. When you en-ter the program, you're greeted with theday, date, and a schedule listing for thecurrent part of the day (morning or af-ternoon). Function keys allow you toscroll forward or backward by half daysor show a calendar of the next 30 days.You can set an alarm for any time on thehalf-hour. It will sound even if the unit isturned off or if you are running anotherprogram.

Some applications are availablethrough CP/M, notably TERM andFILINK, which are communicationsprograms. TERM can be used to link thePX-8 with a remote computer. However,it is a bare bones program. Users whoneed a more sophisticated communica-tions program will have to obtain it froma source other than Epson right now.FILINK is a specialized program used

(Continued on page 99)

92Computers & Electronics

TO KEEP UPWITH TODTECHNO

4te

When you turn toComputers & Electronics, you're

' reading the world's foremost publicationcovering the microcomputer industry -where last night's discovery is today's

technology. Computers & Electronics is your direct link to state-of-the-art information in:

Microcomputer DevelopmentsWhether you're investing $300 or $3000, turn to Computers &Electronics first. You'll find candid test reports of all major newmicrocomputers ...from the Commodore 64 to the Apple 'Ile tothe IBM-PCXT. And you'll discover which unit has the power,software and expansion capability to meet your specific needs. Atyour specific budget.

New Peripherals and SoftwareMicro programs and add-ons are in-creasing almost geometrically. LetComputers & Electronics sort it all outfor you.

You'll get features like a buyer'sguide to printers. A preview of the firstworkable economical thesaurus pro-gram that runs on virtually any CP/M- based system.Advance looks at new products like a joystick forVisicalc®...disk drive assemblies...a color monitor forthe IBM-PC.

Increase Your Computer Science I.Q.Compute.rs & Electronics will enlighten you with eosy-to-understand discussions of computer fundamentals.Such as the series on learning 16 -bit microcomputertechnology and an in-depth look at the structure of CP/M

You'll also delve into the future with articles like SuperChip: next -generation personal computers with doublethe performance at a lower price.

.041 -

DON'T MISS ONEe ,11%110. / INFORMATIVE ISSUE.

SAVE UP_70 37%!SUBSCRIBE NOW AND

r&ELECT R O N IC 5

vi

HAVEWHERE

TURN.

Plenty of Hands -On Action, TooWith expert input from Computers & Electronics,

and your own electronics savvy, you'll find dozensof ways to experiment with...upgrade...and increase

the versatility and performance of your system.For example, with less than $3 and very little time, you

con add a feature to your keyboard that letsyou automatically repeat a character by hold-

ing down a key. Or you might want to build a circuitthat lets you match a 600 -baud CoCo to a 300 -baud printer.

Heard about the important new electrically -erasable PROMs? Computers & Electronics willkeep you filled in on the improved memory chips asthey're produced - how they work, how to wirethem, what applications to use them for.

Get Every Issue...PLUS Savings up to 37%!If you're not getting every informative issue of Computers & Elec-tronics, there's a gap in your knowledge - and enjoyment - oftoday's high-speed, high-tech revolution. And now's the best timeto subscribe, while this introductory offer is in effect: One year (12big issues) for just $12.97, with long-term savings available upto 37%!

So keep up with what's happening. Turn to the special postpaidorder card or the coupon below...now!

s ..r..sy COMMIT" 11.4111110

tiiP.O. Box 2774Boulder, CO 80322

YES! Keep me tuned in with Computers & Electronics for theterm I've checked below

0 One year (' 2 issues) just $12.97 -I save 24%!0 Two years just $22.97-1 save 32%!0 Three years just $31.97 - I save 37%!

Mr. /Mrs. /Ms.

(Savings based onfull one-yearsubscription priceof 516,97)

(please print full name)

Address

CE4Z00/

Apt.

City State Zip

1

CHECK ONE: Payment enclosed. ri Bill me later.Please charge my credit card: 0 American Express 0 MasterCard 0 Visa

Cord No. Exp. DateAdd $5 a year in Canada; all other foreign ado 93a year. Please allow 30-60 days for delivery of first issue.

NEW PRODUCTSFOUR-COLORPRINTERA four-color letter -sized plot-ter from Sharp Electronicsuses black, blue, green andred. The colors can be pro-grammed to change automati-cally. The plotter accepts pa-per up to 81/2" wide but canalso plot on postcard -sizedocuments. An RS -232C seri-al and Centronics -style paral-lel interface are built-in asstandard features. The CE -515P plotter will be bundledwith Softkey's Keychart soft-ware, which is compatible

with the IBM PC. The plottermay also be driven by microsthat use BASIC if they areequipped with a printer inter-face cord or I/O port. $399Circle No. 83 on Free Information Card

MOM wirommairniaiMEMICUT -SHEET FEEDERSVI% itar is marketing a line offour cut -sheet feeders for pop-ular computer printers. Feed-ers are available for selectedmodels of C. Itoh, Diablo,Facidata, Morrow, NEC,Philips, Sanyo, Televideo,Toshiba, and Silver -Reedprinters. No tools are neededto attach the feeders to theprinters, nor is there any needfor making electrical connec-tions. With a feeder installedon a printer, up to 200 sheetsof paper can be handled, andthe printer has forms -han-dling capabilities, includingsuper/subscripting and allother special functions con-tained in software. Paper po-sitioning is adjustable be-tween 7" and 14". Ribbonsand printwheels can bechanged, and envelopes,checks, and labels can be in-serted without removing thefeeder. Less than $400.Circle No. 84 on Free information Card

COMPUTER SECURITYDEVICEAdalogic's Gateway pass-word device provides protec-tion against unauthorized ac-cess to computers. Thestand-alone device requiresentry of both correct ID codeand a password. If three in-correct codes are entered con-secutively, the modem is auto-matically disconnected. Thesame occurs if time runs outin the user -defined time -limitlogon mode. Up to 20 pass-words and user ID codes,each containing up to 20 al-phanumeric and special char-acters and spaces, are easilydefined and changed. Themenu -driven Gateway keepsa record of all successful andunsuccessful log -on attempts,even if power should be inter-rupted from its nonvolatilememory. The RS -232 full -du-plex serial device can operateat 300/1200 baud on dial -uplines or 300/1200/9600 baudon leased lines. It automati-cally handles even, odd,mark, space, and no parity.$395. Gateway is transparentto the host computer.Circle No. 80 on Free Information Card

to otYPAPIA 00frip11101. NP

J

DOT MATRIXPRINTERThe Electronic Compact NPis a new dot matrix printerfrom Olympia USA. Theprinter comes with a parallelCentronics -compatible inter-face and features a 9 -pin printhead capable of a full 96 -IOW

10 -Mb HARD DISKA comparatively low-cost 10 -Mb hard disk, from Kamer -man Labs, is called theMegaflight 100. The disk iscompatible with the IBM PCand XT, Compaq, Leading

character ASCII set with de-scenders and seven interna-tional character sets. It has aprint buffer of 2000 charac-ters and a built-in tractor feedthat can accommodate fan-fold paper up to 10" wide.$499.Circle No 85 on Free Information Card

SOFTWARE SOURCESGraphics Program. Inkwell systems has released a 3.0 updat-ed version of Flexidraw, their interactive software and light penpackage for the Commodore 64 computer. The enhancementsinclude the addition of 16 hi-res colors, a telecommunicationsprogram, new chsk handling functions and expanded drawingcapabilities. Flexidraw's expanded drawing capabilities includefaster routines for lines, circles and boxes, "rubberbanding"and an "eraser" for quick editing. $149.95

Circle No. 92 on Free Information Card

Edge, Corona PC and CoronaPortable, Eagle PC and EagleSpirit, Tava PC and otherIBM-compatible computers.The hard disk uses the DOS2.0 or 2.1 software drivers.The Megaflight 100 system

includes a hard disk drive unitwith a capacity of 12.76 Mbunformatted and 10 Mb for-matted, plus the disk control-ler card with plugs and cables.$895Circle No. 86 on Free Information Card

94 Computers & Electronics

TRANSPORTABLECOMPUTERCompanion Computers'CP/M 2.2 Companion com-pact transportable personalcomputer is built around a 4 -MHz, Z80A CPU and fea-tures 64K of user RAM and192K of RAM disk. Suppliedwith a 5'/4" floppy disk drive(up to two more drives can beadded externally), the com-puter can read and write inIBM, Kaypro, Morrow, andOsborne double -density for-mats. I/0s supplied includetwo RS -232C serial with auto-matic (110 to 19,200) baud

MIK

rate selection, one parallelthat defaults to Centronicsstandard, and a buss for add-ing external drives and 256Kof additional RAM and ROMare provided. CP/M 2.2 andutilities are provided with thecomputer. The computer con-nects between a terminal anda host computer to run CP/Mindependent of the host or tolog communications with thehost for later use. CP/M 2.2Companion measures 14" x7" x 4" and weighs 8 lb. Sim-ple connection to terminalcan be made.Cad* No. 71 on Free Information Card

I

_,4211=EINI

SOFTWARE SOURCESAl -Based Software. Microrim's R:base Clout microcomput-er software with artificial intelligence (AI) components is nowavailable for PC -DOS, MS-DOS, CTOS, BTOS, and UNIXsystems. The natural -language interface is designed for use withthe company's R:base series of relational database managementsoftware. It has a built-in dictionary of 200 words and allowsthe user to add his own vocabulary. On installation, Clout readsthe attributes in the existing database and adds them to the dic-tionary. It then allows the user to continue building the dictio-nary with synonyms for words or operations associated with thedatabase. The process begins with a dialog with the user, whoqueries the computer with a word or series of words not alreadyin the database vocabulary. The user is then asked to define un-familiar terms. Clout also has the ability to search through thedatabase to retrieve records based on adjectives or qualifyingterms. A special feature is the program's ability to make inqui-ries into five different files simultaneously from the 40 files cur-rently available in R:base. $195.

Circle No. 72 on Free Information Card

RGB COLOR VIDEOMONITORPrinceton Graphic Systems'new Model SR -12 is an RGBcolor video monitor that candisplay up to 16 colors simul-taneously and offers both textand graphics display capabili-ties. The 12" diagonal screencan display up to 25 rows of80 columns per row in the textmode and 690 by 480 pixels inthe noninterlaced graphicsmode. Video bandwidth israted at 25 MHz, and mis-convergence is listed at 0.5

mm maximum in the center ofthe screen, 1.0 maximum inthe corners. Power consump-tion at 120 volts ac is 95 watts.The monitor is supplied witha standard DB-9 (nine -pin)cable. $799.Circle No. 91 on Free Information Card

DISKLESS LANCOMPUTERChase Technologies' ModelDL diskless local area net-work personal computerboots directly to the SPC(Server PC) hard disk. Thecomputer features: 8088CPU; socket for 8087 co-processor; Orchid PCnet PlusMultifunction card withI28K of RAM and BNC Tconnector; high -resolutionamber video monitor with in-terface card; IBM -like de-tached keyboard; and 9 ex-pansion slots (3 long, 3 shortavailable to the user). RAMcan be expanded to a systemtotal J 640K. The DL is

...if '1,

claimed to be fully compatiblewith all hardware and soft-ware that runs under DOS 2.0or 2.1 PCnet Local Area Net-work and has the ability to useany of the 256 PCnet address-es. System requirements:PCnet and PC -DOS 2.0 orMS-DOS 2.0. Options in-clude: Orchid Turbo cardwith high-speed 80186 co-processor; parallel and serialport card with clock/calen-dar; color monitor and graph-ics card; floppy disk drives;printer sharing anywhere innetwork; and hard disk sys-tem. 52395.Circle No. 73 on Free Information Card

DISPLAY ADAPTERAn 80 -column display mod-ule for the Commodore C-64computer is available fromBatteries Included. The plug-in Model B.I.-80 module issaid to eliminate the problemsof snow, fuzziness, hashing,and interference encounteredwith other units. It can easilybe switched between the 40 -and 80 -column modes, and itcan be used with CommodoreModels 1701 and 1702 colormonitors or any monochromevideo monitor. The device isfully self -initializing andcomes with an 80 -column op-erating system and BASIC4.0 programming language,including documentation anddescription of use. Also avail-able from Batteries Includedis the BusCard that allows aCommodore -compatible disk(including hard disk) and vir-tually any printer to be addedto the C-64. The device is bothhardware and software invisi-ble. The display adaptercomes with a full machine -language monitor that in-cludes assemble and disas-semble commands.Circa, No. 74 on Free Information Card

September198495

Tape Backup(Continued from page 84)

the only way to make tape easy to use.Interdyne has developed a single reelself -threading system with a fixed read/write head. Measuring only 1.625" x 4"X 6", the transport contains the unre-movable take-up reel (Fig. 6). The self -threading scheme works equally well indrive models using either 1/4" (for up to20M bytes of storage) or 1/2" (for 40Mbytes) tape. The entire package is thesame size as a 31/2" disk drive.

Tandon Corp's TM95 1 (Fig. 7), puts atwist on the idea of tape backup. It takesthe same space as a 51/4" floppy and

stores 50M bytes on a single self -thread-ing reel of 1/2" tape. The reel comes in aproprietary I" X 31/2" cartridge. Thecartridge more closely resembles thekind of cartridge you'd expect to see in avideo recorder than a digital recorder,but Tandon expects them to catch onquickly.

As Times Goes OnThe advent of recording and interface

standards for at least the conventional1/4" cartridge part of the tape industrybodes well for the future prospects of

tape technology. You can use the unitsthat adhere to the standard and knowthat data is safe, even from progress.

Drives that use other recording meth-ods have futures that are less certain, butyou'll continue to see nonstandarddrives in the marketplace. These drivessatisfy needs for more storage or betterperformance, smaller package size orjust a lower price. Nonstandard prob-lems can require nonstandard solutions.A manufacturer that violates currentstandards just may offer the best solu-tion for your system needs.

Data Archiving(Continued from page 85)

Larger filing boxes store up to 50 disk-ettes for $25 or less. Beyond this, thereare available in the marketplace a num-ber of miniature storage cabinets thatflip open or have drawers that slide outand are able to accommodate as many as200 diskettes, depending on size. Mostsuch cabinets come with locks that pre-vent unauthorized individuals from get-ting to the disks, and all have dividers.

Make sure before you purchase filingboxes or cabinets in which to store disk -

ettes that they're made from antistaticmaterials. Otherwise, your disks can bezapped by static electricity on dry days.

A better way to protect your diskettesis to store them in individual packages.These come as small plastic envelopessimilar to those used in photograph al-bums. The envelopes can be organized ina variety of ways. If many people mustuse the same group of diskettes, a rotarystand can give everyone easy access.These storage devices work much like an

ordinary kitchen lazy susan and can ac-commodate 100 or more diskettes.

A notebook type binder can store upto 24 minifloppies or 12 8 -inch floppiesin a very small space. Like the plastic fil-ing boxes mentioned above, the looseleafbinders are available in a variety of col-ors. Since the binders can be stored up-right like notebooks, they can be placedon a bookshelf, right next to the manualsthat came with the disks.

If you like working out of a file cabinet

discwasher

SpikernasterSurge Suppressor

Superior protection for your electronicsAll electronic equipment needsprotection Computers, televisionsand audio systems are alldamaged by periodic electricalsurges in standard wall currentThe Discwasher SpikeMaster is THEsuperior suppressor to protect yourinvestment in equipmentSpikeMaster incorporates thesedesirable features. Multimode suppression systems

protect against fast rise timesurges, absorbing high powersurges quickly

Multistage suppression systems guarantee protection whether the "hot" wire, ground wire orboth deliver destructive surges.

RFI filtering isolates your equipment from interfering radio signals on the power line.The heavy duty Discwasher SpikeMaster is attractively designed for home or office SpikeMasterincorporates four widely spaced outlets, an on off switch with indicator light and a 61 2 Soot powercordIndependent laboratory tests (to stringent IEEE. standards) confirm that SpikeMaster outperformsand out protects suppression devices costing twice as much

discwasher 1407 North Providence Road. P 0 Box 6021. Dept CE. Columbia, MO 65205 USAA DIVISION OF JENSEN an &7Y NK Company

2kV

41kV

OV

-1kV

SurgeThe 1000 volt unsuppressed surgereaches o peak of 2.200 volts

$150 suppressorProtection horn a unit costing over$150 allows an 870 volt surge throughthe line with a 750 von residual surgeclose behind

SpikeMasterSpikeMaster clamps the surge on 30microseconds. WITH SPIKEMASTER. ALOWER PEAK VOLTAGE AND QUICKERRESPONSE TIME MEANS BETTER PRO-TECTION FOR ALL YOUR DELICATEELECTRONIC EQUIPMENT.

96

Circle No. 68 on Free Information Card

Computers & Electronics

ONLY NRI GIVES YOU 1DTALCOMPUTER SYSTEM TRAINING

Your hands-on trainingtakes you inside yourTRS-80 Model 4computer to installintegrated circuits andenlarge memory to 64K.

Electronics comes tolife on your NRIDiscovery Lab'''.

Professional 31/2 digitmultimeter with ActionAudio Cassette to talk youthrough operation and use.

Model 4 TechnicalReference Manualenriches your training

Bits -size lessonsbuild knowledgeand understandingstep by step.

COMPUTER MONITOR DISC DRIVE PRINTER AND SOFTWARE...It's all included with NRI at-hometraining in Microcomputers andMicroprocessors. And only withNRI training.

If you really want to learn how to workon computers, you have to learn how towork on computer systems. Only NRIincludes a complete system with yourtraining ...total training that gives youhands-on experience with computers,peripherals, and software.

Get Inside the Famous TRS-80Model 4 Computer

You'll work with one of the mostpopular computers ever designed. Learnprogramming techniques for trouble-shooting ...go inside to expand its RAMfrom 16K to a powerful 64K . . even installa double density floppy disc drive.

You'll become familiar with computerlanguages...run software that demon-strates computer operation ...even becomeproficient at modifying programs to fit yourbusiness or family computing needs.Add High Performance PeripheralPrinter

Only NRI gives you total systemtraining with the flexible Gemini 10X printeras part of your hands-on learning. Workingwith it, you'll get practical experience inadding peripherals, learn maintenance andservicing operations. And you'll use it forhard copies of important programs,business records, and word processing.

Understanding Built On ExperienceYou start with the basics, rapidly build

September 1984

Bu :h in monitordisplays up to 80characters for easyword processingand spread sheetprograms.

on thefundamentalsof electronicswith bite -sizelessons to masteradvanced concepts like digital IDgic,microprocessors, and computermemories.

You'll use the exclusive NRI DiscoveryLab(' to see what makes transistors tick,build and test working electronic circuitsthat duplicate key computer circuitry, con-struct digital logic circuits that demon-strate computer performance. And, you'llprobe into the very heart of your computerusing the Discovery Lab and professionaldigital multimeter included in your train-ing program.

More practical experience as youinstall double -density floppydisk drive. Software includesTRSDOS', DOSPLUSe, machinelanguage monitor, and two gameprograms.

9 x 9 dot matrixprinter completesyour computersystem.

Do It at Home in YourSpare Time

NRI trains you in your ownhome at your convenience. You

learn at your own pace, backed at alltimes by your own NRI instructor and

the entire NRI staff of educators andengineers. They're always ready to answer

questions and help you over the rough spotsto keep you moving toward your goal.

Free Catalog Tells Much More...Send Today

See all the interactive training equip-ment you get in this state-of-the-art coursein today's technology. Look over the lessonoutlines and descriptions of the excitingexperiments you'll perform. And look atother high-tech career fields like Robotics,TV/Video/ Audio Servicing and DataCommunications.

Mail the coupon today to see how NRIcan give you the skills and confidence youneed to start a good -paying career as amicrocomputer technician.

SCHOOLS

McGraw-Hill Continuing Education Center3939 Wisconsin Avenue, N.W., Washington, DC 20016

We'll give you tomorrow.

CHECK ONE FREE CATALOG ONLY

Computer Electronics with Microcomputers

Data Communications Robotics & Industrial Controls Color TV. Audio, and Video System Servicing

Electronics Design Technology Digital Electronics

vim

All Career courses

approved under GI bill.

Check for details

Communications Electronics Appliance Servicing Mobile Aircraft Marine Automotive Servicing

CB & Cellular Radio Air Conditioning. Heating. Industrial Electronics Refrigeration. & Solar Technology

Basic Electronics Building Construction Small Engine Servicing

Name (Please Print) Age

Street

CltyiStateilip Accredited by the National Home Study Council

TRS-80 is a trademark of the Radio Shack division of Tandy Corp.

97

Data Archiving

or desk filing drawer, diskette holders inthe form of hanging files are available.Each holder is designed to accommodatetwo 51/4- or one 8 -inch disk.

As careful as you are with your disk-ettes, you can never totally eliminate thepossibility of data loss. A power loss tothe computer, an incorrect command, oreven a machine malfunction can destroydata on a disk mounted in a drive. If youshould lose, say, a mailing list for a newcompany you are starting or, worse yet,the billing records, you can be in a verybad situation. The only way to protectagainst such data loss is through a sys-tem of routine backup.

Backing Up DataYou can back up data in a number of

ways that vary widely in cost, time re-quired to perform the backup, and timeto retrieve the backed -up data once theoriginal data is lost.

The least expensive way to back updata is to make a printed hard copy ofthe data on paper. But the time requiredto rekey the data into your computerfrom the hard copy can range fromhours to days, negating any originalcost -saving advantages. If you need to

only a small part of a file and beable to read it at any time, hard copy hasthe advantage that you don't require acomputer to read it. And hard copies ofmailing lists help keep things going untilthe computer is fixed or the dataretrieved.

Another relatively inexpensive way toensure against data loss is to copy a disk-ette onto another diskette. Most com-puter operating systems have a copycommand that makes this a simple task.

Backing up all your diskettes can takea long time. A number of programs neat-ly solve the backup problem. Jet, whichruns in only the IBM PC and PC -XT,uses special commands that copy datafrom one diskette to another faster thanthe usual copy command. It copies thedisk block by block, instead of the usualfile by file method of the copy command.Jet costs $40 and is well worth the invest-ment if you must frequently make dupli-cates of your disks.

Backed -up diskettes are worthless if,due to improper storage, they aren'tready when you need them. You canstore backups in a container like the oneused for your first copies. But since theyare your "insurance policy" against totalloss, they may need more protectionthan the work diskettes you use in day-to-day operations.

If your data is very important, thinkabout investing in a small safe. Sincefloppy disks are heat sensitive, safes to

store them and other computer mediaare specially made to resist heat, as wellas provide the usual protection againsttheft. Prices for safes are not inexpen-sive, though, ranging from about $1200on up.

Another good policy to follow is stor-age of backup disks in a location otherthan with your working copies, even ifit's only one room away. Should an acci-dent occur in the first room, chances aregood that the room in which the backups

Any electromagnetproduces a fieldthat can affect

the data recordedon a disk

are stored will be spared the damage thathappens to the working copies.

If your data is important enough, youmay want to store it off -site. Most bankshire firms to pick up the tapes with theday's data on deposits and withdrawalsfor delivery to specially protected store-houses. Some of these storehouses aretouted to be earthquake and even nucle-ar bomb proof. The cost of using such aservice is about $30 for pickup within ornear a large city and $35 a month forstorage.

Beyond Floppy BackupIf you have a hard disk system, the de-

mands for ease of recovery are muchgreater, since the data that can be lostcan be dozens to hundreds of times thevolume on a single floppy disk. It couldtake weeks to reenter manually, throughthe keyboard, IOM of data lost from ahard disk system. A backup method thatuses some kind of computer medium,therefore, is essential. The easiest way(and usually most convenient, sincemost hard -disk -based computers have atleast one floppy drive as well) is to backup your hard disk data onto a set of flop-py disks.

About 40 double -Sided, double -densi-ty 51/4 -inch floppy diskettes are neededto back up a 10M hard disk fully. Usingthis approach, it takes up to two hours toback up a IOM hard disk, but the Jet pro-gram mentioned above for the IBM PCand Back -Up 3 and Back -Up 2 for theApple hard disks cut this time to about30 minutes.

A faster way to back up hard disk datais with a cartridge tape system. The sys-tems available are fully discussed in theaccompanying article.

Optical AlternativeIf you're looking for permanent stor-

age, you might want to investigate thenew laser optical disk medium now be-coming available. Depending on the sizeof the disk such a system is designed touse, you can obtain up to a 1000M (1G)storage capacity. This is the amount ofstorage available on about 3000 double -sided, double -density minifloppies.

With the optical disk system, perma-nent storage is in the form of holesburned by a laser into a reflective layeron a glass disk. The disks aren't subjectto data loss from the types of contami-nants that can spell disaster for floppies.

Laser optical disks have many of theattributes of the "ideal" storage medi-um. They aren't subject to data loss fromdust, dirt, smoke, liquids, or electromag-netic fields. Within reason, they're rela-tively immune to the temperatures thatwould ordinarily render a floppy diskuseless. On the negative side, the diskshave glass substrates that won't tolerateabusive handling without shattering, norcan they be erased and be rerecorded asmagnetic media can.

Projected prices for laser optical disksystems are in the range of $6000 to$8000, with the disks themselves beingabout $200 each. What makes the opti-cal system viable is its relatively low per-byte cost, since they are able to store asmuch data as thousands of floppy disks.

The ConsiderationsIn deciding which backup method to

use, keep in mind a few factors. One, ifthe method you choose takes more timethan you want to spend, you probablywon't use it, which means that whateveryou spent for it will have been too much.Two, balance your time in making back-ups against cost. A more expensive meth-od may make sense if you wouldn't havethe time to use a less -expensive method.

A third factor to consider is how oftenyou'll want to make backups. Thoughexperts differ on how often you shouldback up your data, the best rule to followis: If you need the data, back your disksup immediately!

Closing CommentThrough proper care, you can prevent

most accidental data losses, but bear inmind that no matter how careful youare, data can still be lost. So it's wise toinvest in some sort of backup system anduse it before you lose important data. 0

98 Computers & Electronics

Epson PX-8(Continued from page 92)

only for sending and receiving WordStarfiles between the PX-8 and Epson'sdesktop computer, the QX-10.

The PX-8 comes with four manuals-the User's Manual, BASIC ReferenceManual, Portable WordStar, and PortableCalc/Portable Scheduler. Epson manualsare always well written, though some-times not thorough enough. The User'sManual, however, is very thorough andprovides most of the information a seriouscomputerist would need to get optimumuse from the machine. (For even more ex-tensive information, OS and TechnicalReference manuals are available.)

The BASIC manual is also excellent,providing the user with a reference to allthe commands, plus a wealth of exam-ples to illustrate them. Again, a typicallywell written Epson manual.

Both the WordStar and PortableCalc/Scheduler manuals were producedby MicroPro. Though some of theirmanuals have been criticized in the past,these are as good as the most recently re-vised manuals that accompany theirstandard products. They are on a parwith those produced by Epson.

The PX-8 andits peripherals

offer a complete,portable package

ConclusionsWith the PX-8, Epson has taken gi-

gantic strides in placing the full power ofa desktop computer into a moderatelypriced portable unit. For people familiarwith the CP/M operating system andMicroPro products, this machine shouldbe enormously popular. For thosecomputerists familiar with other operat-ing systems, however, I believe the ma-chine will have less appeal. Those whoare new to computing and attracted tothe machine will face a serious dilemma-whether or not to invest the time nec-essary to learn two fairly complex piecesof software: CP/M and WordStar.

The machine does have its faults, no-tably a screen display with less than opti-mum readability and software that doesnot interact well with keyboard features.Its overall utility, however, far out-weighs these minor problems. The PX-8and its peripherals offer users a completesystem in a portable package. Thoughthe ultimate wish list might include suchfeatures as a 24 -line screen display,Epson has produced an extremely capa-ble portable at a very affordable price. 0

5Why are over

of our customerssince1978 repeaters?

It's very simple .

they call andsave money!

1-800-841-0860For example:

SANYO MBC SERIESWe have the LOWEST prices.

Call us before you buy.

COMPUTERS

Ralpq Jhack

COLUMBIA

FraspivilawaiwwwwwwwwComputer

PRINTERS

STAR MICRONICSGEMINI 10X

'245

EPSON OKICATA

Or'' C. Itoh

cifIlisywriter mrial

MANNESMANNTALLY

Transtar

EQUIPMENT

Diablo * TAXAN

VISA and MasterCard accepted, also Wire Transfer of fundsdirectly from your bank to ours

Namebrands atwholesaleprices

micromanagementsystems, inc.

2803 Thomasville Road EastCairo, Georgia 31728

For info, call 912-377-7120

Ask fora free copy

of ourlatest catalog

September 1984Circle No. 12 on Free Information Card

9.1

IF YOUSUBSCRIBE TO

PLEASE READTHIS

... Take a moment now and remove yourmailing label and save it with this message.Your label is very important and helps us to

help you quickly! When moving, send us your label withyour new address 8 weeks before youmove to COMPUTERS & ELECTRONICS,

P.O. Box 2774, Boulder, Colorado 80322. If you have a question about your

subscription, simply send us a note withyour label, or a note with your name,address and Personal IdentificationNumber to P.O. Box 2774, Boulder,

Colorado 80322.

r

of

o

0

L

Name

Company

Address

ci)_oa 0

43-

City State Zip

If you have just subscribed, youll receiveyour first issue in 30 to 60 days.

AT&T(Continued from page 69)

stantly maintained and checked bymeans of the three -bit code that comes atthe end of each burst.

The time compression multiplexer de-scribed in the sidebar (on page 102) is theheart of the CSDC system. Once the sys-tem is in operation it will be located inthe local exchange. What the user willsee is a black box (leased from the localphone company) containing the termi-nating equipment that connects to thetwo -wire telephone line. The circuit inthe box will be a variation of the stan-dard hybrid arrangement used to splittwo -wire transmission into four wires.The user will see eight wires: two fordata transmission, two for data recep-tion, two for voice and two for switchingback and forth between the data andvoice modes. The user will be able tohave equipment designed to connect di-rectly to the CSDC or adapt the-CSDCto one of the standard terminal configu-rations, such as the RS -232.

Considering thecomplexity of the

entire CSDC system,using it will be

remarkably easy

Using CSDCConsidering the comple \ity of the en-

tire CSDC system (Fig. 2). using it willbe remarkably easy. You will dial a spe-cial access code to get connected to thesystem even if your local exchangedoesn't have CSDC equipment on thepremises. As long as the exchange is onthe digital data trunk (the T -carrier), theaccess code will automatically route thecall to the nearest exchange with theequipment. Once you answer the phonea normal voice conversation can takeplace. When both parties agree, they canswitch to the data mode and back to thevoice mode. You will hear warning sig-nals if the two ends of the call are not inthe same mode. There will be no limit tothe number of times you can switch be-tween the two modes.

The advantages possible with 56-kilobaud transmission are endless. Sincedata can be sent in a short time, it mayprove to be cheaper to use CSDC totransfer batch data than to transportcomputer tapes. Direct dial modems willbe able to start dumping data automati-cally as soon as the connection is made

With CSDC, ahigh -resolution

copywill takeless than4 seconds

between the two telephones. An offshootof high-speed data dumping is quick fac-simile transmission. Now the most ex-pensive machines can transmit low -reso-lution 8'/2" X 11" copies in about 30seconds; most other equipment can takeup to 6 minutes to do it. With CSDC ahigh -resolution copy will take less than 4seconds.

By operating in the data mode and us-ing the proper analog -to -digital conver-sion techniques, you will be able to sendand receive high-fidelity speech and mu-sic with a greater bandwidth than is cur-rently available even on special dedicat-ed lines. By using the proper terminalsoftware, you will be able to mix graph-ics with high-fidelity voice. At the mo-ment, graphics can be sent over a dial -upline at a maximum rate of 4.8 kilobaud.CSDC will increase it tenfold.

Security can also be improved withthe increased baud rate. The digital andanalog techniques now used for voicescrambling have severe limitations. Dig-ital means are limited to the baud ratepossible on a standard loop; analog typesare not very secure. Both methods oftenresult in distorted sound, half -duplex op-eration and poor audio quality. CSDC'sdial -up service is likely to lead to a newdigital encoding scheme providingtighter security and better fidelity ofspeech.

Even if your computer cannot handlethe 56-kilobaud rate of CSDC you willbenefit. If you transmit at only 4800baud you will enjoy a fourfold increaseover the 1200 baud that you may be us-ing now. If your transmission is now at300 baud, it will become 16 times faster.

The number of uses for CSDC is any-body's guess. Once it is in operation,there are sure to be new hardware andsoftware packages to take advantage ofits possibilities. Although most of the ap-plications mentioned are aimed at busi-nesses, the expanding hordes of homecomputerists will be sure to find ways touse the service that even AT&T can'tanticinate. 0

100 Computers & Electronics

WIN AN AMIE

SWIII;STAKISAND SAVE UP TO 33% ON A+ MAGAZINE

The A+ Sweepstakes is open to allour readers-no purchase is necessary-and you can win the new$2,000* Apple Ilc System!

410

7,411t der41*

.40. +ice*

It's Easy to Enter...

Just mail the attached card or cou-pon below after filling in your nameand address -and be sure to indicatewhether you're also subscribing to A+at our special rates, saving up to 33%!

OFFICIAL RULES-NO PURCHASE NECESSARY1 On an official entry lorm or 3' X 5' piece of paper.

handprint your name, address and zip -code Enter asoften as you wish, but mail each entry separately to,A+ SWEEPSTAKES, PO. Box 2928 Boulder. Colorado80322 Entries must be received no later than Octo-ber 31. 1984, and the drawing will be held by Novem-ber 30. 1984 All entries become the property of A+Magazine, which reserves the right to reprint thename and address of the winner

2 The winner will be selected in a random drawing fromamong all entries received. under the supervision ofthe publishers of A+ Magazine. whose decision willbe final. Only one prize will be awarded in this Sweep-stakes. Winner will be notified by moil and may berequired to execute an affidavit of eligibility andrelease. Odds of winning will depend on the numberof entries received Ziff -Davis will arrange for winnersto pick up their prize at a local Apple dealer. Anymanufacturer's warranties will apply, but Ziff -Davismakes no warranties to any prizes. Prize is not transfer-able. No substitution for prizes. Taxes are the responsi-bility of the winner.

3. Sweepstakes open to all residents of the U.S.. ifs territo-ries and possessions, except employees (and theirfamilies) of Ziff -Davis Publishing Company. its affiliatesand its advertising and promotion agencies. Voidwherever prohibited or restricted by law

4. For the winner's name. send a stamped. self-addressed envelope to A+ SWEEPSTAKES. CirculationDepartment. Ziff -Davis Publishing Company, One ParkAvenue. 4th Floor. New York. NY 10016.

Just imagine, if you're the lucky winneryou can pick up your 71/2 pound systemand carry it home with you! You'll getover $2,000. worth of equipmentincluding the Apple Inc with a built indisk -drive, 128K RAM and 16K ROM,Applesoft BASIC and Mouse Text, PLUSthe new flat panel LCD display andMouse! But why dream? Send in yourEntry Card today, and save up to33% on A+!

Make All Of Your ComputingDreams Come True With A+!

A+, The Independent GuideFor Apple Computingmakes computing imagi-native and educational.

Every month you'll receivenew business, education, game

and personal applications that willhelp you expand the use of your Apple11,11+, Ile, III Lisa, Macintosh or the new //cin your home, office or school! In-depthreviews (and previews) of new hard-ware, software and peripherals makesA+ the only magazine you'll ever needto make your Apple grow!

\OUR APPLE

CONWOOCO 101Km CO &PIO

CCE.O4once Lil Oo .1.4C0004 Co00

POMO

&CONN,16nO, MACccOCMOD

MCO61

LoCIfiOC

Enjoy a year or more of A+ at our lowprices-save up to 33% and enter theA+ Sweepstakes today! It's an op-portunity you won't want to pass up

.nasec on manufacturer < suggested list price

OFFICIAL ENTRY FORM

SWEEPSTAKESP.O. Box 2928, Boulder, CO 80322

Y E S Enter my name in the A+ SWEEPSTAKES and start my subscription toA+ Magazine for the term checked:

One year tor S19 97. Two years for 536.97. Three years for $49.97SAVE 20%, SAVE 26%, SAVE 33%,

Savings based on full one-year (12 issJes) subscription price of $24.97.

N0 I don't wish to subscnbe now, but please tell me if I've won the Apple Inc.

Mr Mrs 'Ms

Company

Address

please print full name

AM8Z003

City State Zip

Cheek one: Payment enclosed Bill me later Charge my: AMEX Li Visa MasterCarc

Card No. Exp. DatePlease allow 30 to 60 days for delivery of first issue. Add 512 per year in Canada and all other foreign countries

AT&T

TIME COMPRESSION MULTIPLEXINGThe heart of the CSDC system isthe time compression multiplex-er; and the heart of the multiplex-

er is the VLSI (very large scale integra-tion) chip that was developed for it.

Four separate areas of ROM werebuilt into the chip to handle differentphases of the compresssion-expansionprocedure. A 448 x 14 ROM and a 448 x12 ROM control the receive and trans-mit operations, respectively. Two other2K blocks of ROM contain the algo-rithms needed to scramble and unscram-ble the data sent over the line. (Scram-bling ensures that the loop only handlesdata and prevents errors being generatedwhen a user it. either not sending data oris sending a long string of zeros.) The en-tire scrambling operation is completelytransparent to the user.

Two 128 -byte RAMs are input and

output buffers for storing the com-pressed data after it is received and be-fore it is transmitted. Because so muchmemory is used, the architecture of theIC has an internal 8 -bit data bus with se-rial input and output ports. Data is re-ceived and transmitted serially bit by bitbut is handled internally in parallel atthe byte rate. This lowering of the oper-ating speed and the use of CMOS fabri-cation technology have reduced the dis-sipation of the VLSI chip to less than 15milliwatts.

The ROMs that control receiving andtransmitting are designed so that whenone is operating, it turns the other off.This alternation helps prevent overlap-ping of data and consequential errors.When the chip receives data it checks forerrors and breaks it into 7 -bit segments.It adds an eighth bit and reads the corn-

pleted segment into the RAM at an 8-kilobaud rate. When 24 bytes have beenstored in RAM, the data is compressedand a burst is formed by reading the dataout at a high rate. At the same time, aseach byte is read out, the scrambling al-gorithm is applied and the byte isXORed (exclusive or'd) with the code.Then the byte is converted from parallelto serial format and the data is clockedout onto the T -carrier transmission line.

When the burst is received at the otherend, it is converted from serial to paral-lel, and the last three bits are synchro-nized. If errors are detected in four con-secutive bursts, the receivingmultiplexer sends a code to the transmit-ter that halts data flow and restarts theburst synchronizing procedure. Oncesynchronization is reestablished, datatransmission starts again. 0

An excellent computer deserves Vint"Diskettes.

Don't settle for a diskette that doesn't measure upto the quality and performance you expect from yourcomputer system.

Choose the best - X'Int diskettes. The onebrand that you can count on to protect all of yourvaluable information.

Every X'Int diskette is burnished and thenPerma Sealedn'in a rugged vinyl jacket designed toprotect your data longer; you can actually feel thedifference. And the hub ring is reinforced to helpprctect it against abuse. That's why we can offeryou an unlimited lifetime warranty.

Your computer system is only as goodas the diskette you put in it, so if you wantexcellent performance, use X'Int flexiblediskettes. We live up to our name.

Only at an X'Int dealer near you.

FLEXIBLE DISKETTES

X'Int Diskette Products. inc.,630 International Parkway. Richardson. TX 75081

Circle No. 63 on Free Information Card102

Computers & Electronics

INTRODUCING HAVAC.THE NEXT BEST PERSONAL COMPUTER

If you're buying a personalcomputer for the first time, you don'tneed the biggest and brightest tobegin with.

Think simple.Sensibly priced.Less than $850.Of course, you'll want some

initial training to get you started.r.LM

The Havac comes with its owndisk operating system and "Train-ing" software like Typewriter, Calculator and Havacom for communi-cations. And once you've mastered the basics, you can use softwarefrom the largest selection in the world.

Apple° Software.Game- like computers that are comparably priced can't offer

software like Havac can. But if games are your bag, Havac has a Joy-stick/Paddle port. And a port for RS -232C,Parallel/Serial printer or an additional diskdrive. Which we also make. Havac already

,..-.004

has one disk drive built in. Ar -So, if the biggest and brightest are beyond

your budget, take a look at The est PersonalComputer. Ailiw-, ,,.. The Havac from

MICROSCI.Ask your

dealer for a simple demonstra-tion or write: MICROSCI, 2158

Hathaway, Santa Ana, CA 92705(714) 241-5600.

MIMM' 41011 0 IWAII .1 4 .A M

Apple' IS a registered trademark 01 Apple Computer Inc

,IA -SCIMICROSCI

A :standun < 0111p.111,

September1984

disc 40 column/24 line screen 2S0 142 dot color graphics 4 cursor keys and 2 specia. t unction keys. Compact and transportable Made In America

Orem No. 18 on Free inronna" von"- - Card 103

Interfaces(Continued from page 58)

A wide variety of A/D converter tech-nologies exist. Types that use successiveapproximation and dual slope integrat-ing rely on counter/comparator logic.Others employ charge balancing andflash inputs. The various types differ intheir respective abilities to perform aconversion with a certain accuracy in acertain time. In practice, most of the"plug-in and run" A/D interface prod-ucts operate with the A/D technologytransparent to the user. Naturally, thecost of the A/D is proportional to thespeed and accuracy with which the con-verter operates.

By adding a multiplexed front end tothe D/A and A/D, manufacturers havecreated the data acquisition system(DAS), an interface device capable ofcapturing and converting a number ofdifferent analog signals (Fig. 2C). Sincethe bulk of the cost of a converter lies inthe D/A-comparator-counter section,the DAS provides a low-cost solution formultiple inputs, at the sacrifice of speed.

Conversion Products StressFlexibility

Manufacturers offer conversion prod-

ucts ranging from discrete cards to com-plete hardware/software systems gearedfor particular applications.

The microprocessor -based Starbuck8232 is a complete data acquisition andcontrol system that connects to anycomputer equipped with a standard seri-al RS -232 communications port. It in -

Most plug-in and runA/D interface prod-

ucts operate with theA/D technology

transparent to users

eludes eight protected analog input lines.eight protected digital input lines andeight opto-isolated digital output lines.

The AOM-12 4 -channel D/A andAIM -12 32/16 channel A/D convertercard pair offer high accuracy and highspeed for your S-100 bus (IEEE 696) sys-tem. Onboard DIP switches set the ad-

dresses for each board. Multiple boardsmay be used for giving or taking data toor from the outside world.

The Home Automatic Weather Sta-tion (HAWS) is a complete hardwareand software package that allows ama-teur or professional meteorologists tomonitor changing weather. The HAWSsystem contains sensors and conversioncircuitry that allow VIC 20 or Commo-dore 64 computers to measure tempera-tures from + 140 F to -130 F, relativehumidity from 0 to 100% and atmo-spheric pressure from 1060 mBar to 3MBar. Obtaining these weather valuesfrom HAWS requires nothing more thanloading a tape or disk and pressing a fewkeys. Additional programs cover com-fort factors, chill factors, cloud altitudeestimating, metric -to -English conver-sion, trend graphing and forecasting.

The Analog Interface Board offersan eight -channel A/D and an eight -channel D/A converter system to own-ers of the TRS-80 Color Computer,Commodore 64, Apple II and Ile andTimex 1000/1500/2068. Each channelhas 8 -bit resolution. The analog chan-

(Continued on page 106)

QUALITY COMPONENTS NOT MAIL ORDER 'SECONDS -r

ARIES ZEROINSERTIONFORCESOCKETS -cam actuated. true zeroinsertion - tin plated soldertail pins - capable of beingPlugged into dip sockets,including wire wrap

Nock No ofNo Plea 1.9

r 7055 24 4 9017056 211 5 1517057 40 0 5111056 161 ' 2 02

10.49 50

fa 35 $390450 405595 535

7050 945

rK 5001.1115- Nem Nese No NosUNITRACIM *moos see C 96.rnm .111.7 ....nom 22225 14 5.211144,1r.'",°,:,,,:. 22225 II -21/.1.1.0 IC Scoter on 222211 18.20 211

wet cometeo heel.e bottom a IC sod

emeteree Wont**.Now

SCREW MACHINED SOCKET 7. I ''PINS. 10060 Loc... n begs ot 1 I ..- it103 $100, NO 11310 .5 Settler tallwr02 gold collet 1.n s1.1 Stock No I .1 1 311 a owe 400 with grad collet Ms isr . I-000 shell

_

NewDerienotion ass a... sees

1.310 Sea or *00 . 1 4 45 63 IN

wre war/ we. I r es to 75 50 t" 9

WILD ROVERTouch switch cep.*Opermfnp motron a 005 wolhOut the

ae 01 a ieveted arm E attem.h RIM onand on with be. nose Normally openweds 15 VAC 6 amp 30 maliohm r.sal. 615 radius by 160 iv.

Stock No. I tOaUp12098 Si 42 si 28

80/40 ROSIN CORE SOLDERSures Lamm. *.lent No Die aeon roe t era..50015 092 9 15 lt In

50076 062 25 4 2 3350077 OBI 50 6 4 2,30011 032 33 1 5 1 1,.0079 032 a 5 4 2 450080 032 I75 s 4 51

EKI KITS comewith all partsnecessary toassemble' Stock No 88844TV Jammer Kit 'wipesout" your TVscreen $ 7.71 Stock No 88850Whopper Alarm Kitmakes a great alarmOr siren $1 1.33MANY, MANY MOREKITS AVAILABLE INFULL LINE CATALOG

Low profile 050 inchcenters can be bentor folded or -zipped"to separate individualconnectors Inter-laces with all insula-tion displacementconnects's'

3M Scotch Fix'INSULATION DIS-PLACEMENT CABLES

.OM";;:°sC S. OU MOLLS MOUSro'VZ.e Gee. start.0 ,,

g;'1'N03306 . 71 1 n 50 340330 SO .9 ea 74 4a, es

41?,eV. lizonersejir.C.r1; c2.1141. A t%03315 iii 22 S.317 24 41 t 34 4103323 40 , ee es 57 MI'00::, .....2c1"0333076 4 .

37 .?..1 11,403334 75 ]0 Li 02 52 7203340 . 1355] roe so arse03347 SO role 90 11231 10943

The Battery Just Wrap' Toolorrr, 100 1813,

11,115 around 025 ...moo. .11 our neontor perculting and pee sharong Comoret.*trays end r00 51 30 AWG were

.e. Moe. No Ormenteron P,.-.N. 4700 3340 a-aBetiroAst rzYr toor.z. trr

-

ale 3$134, neleacernent to 35

'1342 100,1 W. apiacement vont 541713 100 R 7.4.,vOlocernent ova 7 54f op rt moo .re 7 S4

44- ' rn014 nnntol nne 7 54

OK MACHINE AND TOOLIC INSERTION/

a emereamerma a! EXTRACTION KITintrod. DIP IC .1r.10,11 sod4164,44.10.004.0.1141.41Csfrom 14 lo 40 one Tools 7.1snoop conductive...limper.C205 We and include ern,.

MICRO Charts 1' 01, J, 01" cnans ornonale need 10aurnItte through menu..nd summer*. Fully decoded

oaten, ecru loyallyorkroenensme grew pn0113 C.. tweet b oluy n eEek. .ele

Wadi No RA -.eon23070 ZOO CPU23011 1110170AA608SA23012 650 115539123013 8048 and relative.23014 54, 400 TTL Ihnouta23015 119.0 Alporlthms

PrNe ir.S-rra;'55 95

5 953955 955 95S 95

/If 1

*41.34

SOCKET WRAP IDCho socket 000011114 pane.tr. numbered notes 01010.hon. Sler onto socket WO.owe noseenne 10 dent., oneA150 0711, On ther1,10110Cat.on,C pad 110021.0 tuner.," *lc

-ni4es 4.,e ..isont)61.95 par peck

Send SI 00 postage and handlingfor FREE COMPLETE CATALOGwhich includes coupon for St 00 OFF purchase

I R F

WRAPSOCKETSTin platedphosphor bronzecontact -3 wrapStockNo No Pins 1-99

11301 8 5.4011302 14 5911 303 16 6411304 HS 7311305 20 991 1 3011 22 1,1211307 24 1.251 1308 28 1.5211 309 40 2.05

Special of the Month'ANTI -STATIC BUG BOX -h...10 compartment. nlessunng X 375X 5 deep Each Bug Boa will store 60prat -pen DIPs, 30 touneen-pon DIP* 30Ndeen-Pin D117.01 30 other weecomponent...I, as transietors, diodes,resistor networks. etc The transparentcover ria. Menet.0 desogn that allowsSi,. user to empty one comperrment ettime A numbering system on the coverpores an instant COunt 131 rernarning IC.STOCK NO. DESCRIPTION PRICE

12803A8 Package of 10 ww-lasater23A/Rewe Huse 518'9

PIN FORMING TOOLputs ICS On theirrue row to row

l4 31spacing One side istor 300 centers. Flip tool ONE TOOL DOESover for devices 8 thou 40 PINS!600 centers Put device

tool and squeeze. Seta Me. PriesHand Tool looto 512.55

NEWT ANTI -STATIC MODEL 90200 $14.98

13. '

129) 16 en112911 20 en13299 22 en13300 24 on330, 26 en

r 3302-01101 m

LOW PROFILE DIP SWITCHESHomed 13011075 Ttic MOO Or410 1 34 25-9014 plated "0351 3

139.

10352 4 1 .1

353 5 149 30"0354 1 50 , 4010355 r SO 4S1.84

2 ,S0 1

1

OS1.571.6. 10 2 t 2 06

100-499 500S 38 5.30

54 .4558 .48.65 .55.90 .75

1.02 .851.14 .951 38 1.151 86 1 55

TI LOWSOCKETSTin platedcopper alloy688 contact pinswith gas tight sealStock 100 -No No Prne 1-24 25-99 999

11201 6 1.10 5.09 5.08112021120311204112051 1 206

2071 1 205

1209

14 .14 .13 .1218 .18 .15 .14111 18 .17 .1520 .20 .18 .1822 .22 .20 .1824 .24 .22 .2028 28 .28 .25so 40 .37 33

Lniy,la)p.1 DaMaY5

StockNo12082120851208712089

Common

Color 1 100Red 111.12 .99Green 1.04 1.83yew. 1.92 1.70Orange 2.08 1.84

Right Angie Socket for AboveDisplays

StockNo I 10011010 $1.241.99

OPTEL LCD's with pinsStock No. 47005 Stock

4700547006

Stock No. 47006 41007EBRO

Desorption 1 1031/2 dig 5 S 5.95$ 5.504 dig. 5 5.95 5.504 dig 7 11.90 11,00

B1:113 13 Stock No. 47007

seoSchee:. BreadboardSystems Basc lotcomes well 24venous Dual Sockets.40 various PlugSops, wire and toolskit can be used wet.any 01 the six boards

Stock No. Crescriptron03500 Bove All

0350603507035080350003510

Intel SBC 6010 Board 12.6 75Motorola M-6800 Board. 9 75 x 6S-100 Board. 10 5 3Z-80 Board 7 7 a 7 5Eurooard Board. 61 1 I

Price$79 95

19 5064 .952 9536 9539 9521 95

SINTE 28 8th St.. Box 410C CO. Frenchtown. NJ 08829 F3z-1TOLL 800-526-5960 °INC Eul3E SHIPPING CHARGES

FREE on NJ (201) 996-4093 '''"'''°°"":03t''rye, 52150 SS 00

104 Circle No. 36 on Free Information Card 'oniputurs & Electronics

BIG FOURNEW 128K -MEGA BYTE DUAL DISK DRIVE -80 COLUMN

COMPUTER SYSTEM SALE!HOME BUSINESS WORD PROCESSING

8050Dual Disk Drive

Mega Byte

100 CPS

4023 Printer

7 /

8128 Computer128K rm

List Price $3717.95

LOOK AT ALL YOU GET FOR ONLY $ 895.

12 Hi Res Monitor

LIST PRICE

B128 COMMODORE 128K 80 COLUMN COMPUTER uu

8050 DUAL DISK DRIVE lover 1 million bytes) 1795 004023 100 CPS 80 COLUMN BIDIRECTIONAL PRINTER 499 0012 HI RESOLUTION 80 COLUMN GREEN OR AMBER MONITOR 249 00BOX OF 10 LORAN LIFETIME GUARANTEED DISKS1100 SHEETS FANFOLD PAPERALL CABLES NEEDED FOR INTERFACING

TOTAL LIST PRICE

49 9519 95

102 05

$ 3717.95

Printer replacement options (replace the 4023 with the following at these sale prices)

* Olympia Executive Letter Quality Serial Printer* Comstar Hi Speed 160 CPS 15 Serial Business Printer* Telecommunications Deluxe Modem Package

Professional 80 ColumnWord Processor

Professional Data BaseAccounts ReceivableAccounts Payable

5149 95

149 95149 95149 95

LIST SALE

$ 699 00 $ 399.00$ 779 00 $ 499.00$ 199 00 $ 139.00

Plus You Can Order These Business Programs At Sale Prices

LIST SALE

$99 00

99 0099 0099 00

PayroiiInventoryGeneral LedgerFinancial Spread SheetProgram Generator

LIST: 4 4

4i a. 4

49 4.1

14997

SALE

S99 0099 0099 0099 0099 00

15 DAY FREE TRIAL We give you 15 days to try out this SUPER SYSTEM PACKAGE" If it doesn t meet your e'oectations. lust send it back to us prepaid and we will refund your purchase price"90 DAY IMMEDIATE REPLACEMENT WARRANTY If any of the SUPER SYSTEM PACKAGE es:tail due to faulty workmanship or material we win replace it IMMEDIATELY at no charge

Store HoursMon -Fri 10:30 a.m. to 8:30 p.m.Saturday 9:00 a.m. to 5:00 p.m.Sunday Closed

=

COMPUTER CATALOG SHOWROOM"We love our customers"

22292 Pepper Rd. Barrington, IL 60010Phone 382-5108/382-5244

I,neie No 40 on Free Information Card

September 1984 1115

WHY PAY MORE?BUY AT DEALER PRICES

30 DAY SATISFACTION GUARANTEE(ALL ITEMS 100% APPLE & FRANKLIN COMPAT,BLE)

ZEUS 2001 - s999.00 NOW $524w

ZEUS 3005)Detachable Keyboard) $54900

APPLE + CP/M + 64K* 8 Expansion Slots Auto Repeat Keys* 69 Function Keys * Built-in Cooling Fan* Numeric Key Pad 8 Expandable To 128Ka

Color Graphics Break + Pause Keys

Runs Apple and CP.'M Software

DISK DRIVE* - $275.00 NOW 9 5900* 35 Track SS -DO * Quiet + Reliable Shuggart Mechanism * 90 Day Warranty

YANJEN MONITOR - s179 .0o NOW $119N* 20 MHZ 1.000 Lines At Center

* Amber or Green * Super High Resolution

ACCESSORIES(100% COMPATIBLE TO APPLE AND FRANKLIN)

1 ask Dave Interface Card

2. TEAC Slirnline ask Nero

3 Z-80 CP/M Softcard

4 80 Column Gail W

5 16K RAN Card

6 1286 RAM Card

WAS

S159.00

$285.00

0199.00

5299 00

3159 00

$499.00

NOW

S 59.001199.00

O 79.00$ 99.10

59.10

8199 007 RS -232 Serial Interface 2169 00 79.008 Integer Card S149 00 49 009. Ccumunication Card 5149.00 75.00

10 Parallel Printer Interface 5159.00 S 49.0011 16k To646 Buffer Printertace 0289.00 2139 DO

12 Epson Printer Card 9149.00 29.0013 Prowriror Printer 5595.00 $379.0014. Super 5 -)rinler - 900 W $499.00 3289.0015 T V Interface S 35.00 15.0016. Modem Awe Cat II (with S W I 1389.00 0249.00

If it works or runs on an Apple - itworks or runs on ours

DISCOUNT COMPUTERS3500 S. Orange Ave., Suite st 102

Orlando. Fla. 32806

(305) 425-7770Ask About Our $3.00 Phone Credit

Interfaces(Continued from page 104)

nets act as mapped memory for high-speed operation. Fast Fourier transformsoftware is available for magnitude andphase analysis.

The Lawson Labs control productsline provides Apple II (+ & e) userswith a broad range of data acquisitionand control devices. The Model 34($325) is an 8 -channel 12 -bit DAS thataccepts inputs from 0 to 10 V dc. TheModel 14 ($195) Analog Interface cardcombines a 4 -channel 10 -bit A/D con-verter with an opto-isolated 4 -bit latchedoutput port. A multiplexor card (Model17 $140-$160) allows any Model 34 or14 input channel to be expanded to 8 or16 independent channels. Last, but notleast, the Model 24 control module($120-$180), also used in conjunctionwith the 34 or 14, provides from one tofour double -pole single -throw relays rat-ed 0.5 A. All models feature overvoltageprotection up to 200 V dc.

The single -board DT2808 fromData Translation extends an already im-pressive line of data acquisition and con-trol interfaces. It provides I6 channels of

The list ofnew interfaceproducts and

manufacturersgrows monthly

A/D with 10 -bit resolution, two chan-nels of D/A with 8 -bit accuracy and 16lines of digital input/output. The IBM-compatible card contains an onboardmicroprocessor that acts as the interfacebetween the DT2808 and the PC andalso tends to simplify user access to theboard's functions. PCLAB, a completereal-time software package, supports allboard functions as callable BASIC sub-routines. An optional screw panel allowsfor easy connection of user signals.

The PCVISION Frame Grabber is areal-time video digitizer and displaymodule capable of capturing a standardtelevision camera signal at a rate of 30frames per second. It stores the image inan onboard 512 X 512 x 8 -bit framememory and sipultaneously displaysthe stored image on an external monitor.The image stored in the frame memorycan be accessed by the computer to im-plement algorithms for image enhance-ment, feature extraction, pattern recog-nition and image transmission andarchiving.

The Keithley DAS Series 500 is acomplete family of measurement andcontrol cards that plug into a central sys-tem controller chassis. With measure-ment speeds up to 30,000 data points persecond, conversion accuracies of 12, 14and 16 bits, and the capacity for hun-dreds of analog and digital input/outputchannels, the Series 500 can accommo-date a variety of applications. Directtransducer connection, programmablesignal conditioning, and optional signalisolation eliminate the need for devicesfor external signal conditioning. TheSoft500 integrated software package, anextension of floating point BASIC, tiesthe Series 500 together.

A Few PointersThe list of ness interface products and

manufacturers grows monthly. In themidst of this product blitz, how best canusers determine the quality of a particu-lar interface product?

The better devices are designed toprotect as well as interface your personalcomputer. Look for inputs protectedfrom short circuits and overvoltages andoutputs isolated by optics or transform-ers or relays.

Beware the differences between digi-tal I/O and true switched relay I/O.Digital I/O is designed to control suchpower-hungry digital devices as printersand solid-state power circuitry. It can-not directly control appliances, lamps,and motors, for example. Relay -basedI/O, either electromechanical or solid-state (power transistors, SCRs or triacs)can readily switch loads that would frymost digital I/O circuits.

Finally, for those systems that com-municate over home ac wiring, makecertain that the communication protocolcorresponds to such nonproprietarystandards as those established by theBSR Corporation (known as the X-10protocol) and Leviton. They guaranteethat a source of low-cost switch mod-ules, the controlled end of the system,will be available from sources as close asyour local hardware or departmentstore.

Nothing to It But to Do ItDon't he discouraged if tins mini -

tutorial seems complicated. In practice,the user does not need to understand theworkings of the latest generation of in-terface devices to use them. Most devicesfall into the "plug it in and turn it on"category.

All of the manufacturers representedwill be more than happy to supply litera-ture and additional information if youdesire. 0

Circle No. 6 on Free Information Card 106 Computers & Electronics

Engineering Design(Continued from page 90)

sign can be simulated before a wire hasbeen wrapped.

Outputs from this program may beviewed in real time as graphical wave-forms, analogous to those produced byan oscilloscope or a logic analyzer. It cansimulate both at the logical gate andtransistor or switch levels and modelhigh-level functional blocks like ROMand RAM.

PC Logs supports three logic states(low, high and unknown) in four drivingstrengths (supply, driving, resistive, andhigh -Z). This organization allows mod-eling of most devices. In addition, vari-able delays along with spikes and zero -delay oscillations may also be modeled.

This combination of packages is notinexpensive: The software alone costsover $10,000. Together, however, thesepackages give an IBM PC the CAE ca-pabilities that systems costing over$100,000 did not have a few years ago.

FutureNet's Dash -1 and STRIDESThe most complicated of design tasks,

IC design, is brought to the PC byFutureNet Corporation of Canoga Park,CA. Its software packages-Dash-1, a

CAD is also here foravocational use

schematic design package, andSTRIDES (structured interactive designsystem), which adds on to Dash-l-letan engineer construct a drawing treewithin one system. This structure ex-tends the capability of Dash -1 to doingIC design.

Because the system supports up to 99levels of hierarchy, a design can start outas a "black box" and eventually reachthe logic gate level. Both top -down andbottom -up design strategies can be ac-commodated with the system.

In addition, Dash -1 and STRIDES es-tablish links between the IBM PC andlarge CAD systems. As a result, pin lists,net lists, and lists of materials can bedownloaded to more powerful CAD sys-tems, like those from ComputerVisionor IBM.

In just a few years CAD has descend-ed from the heights of mainframe com-puters. Now, with a PC in one handand-for some applications at least-amoderate number of dollars in the other,a designer or engineer working alone orin a small office can tap the versatility ofcomputer -aided design. In fact, CAD ishere for avocational designers, too. 0

NICE may be only 3" square and 12" thick, hut it hands u speed,real-time emulation for the Z80-over 50 emulation functions,breakpoints, all memory addresses and all I/O ports.

Just plug NICE directly into the tasse4.7,80 socket anfor system development, trotibleshooting, debugging t. 'ngin the lab or in the field.

Any NICE hands youldl-kbiverfoirtiance, po$498'. . the hest eandator price /fikkriformance ratio 6

Call in your order iudiy piingyour VISA or MaArcard run*her: (800) NICOLE'," outsideCA,seonrd(4y1ou5)r490-8300 in CA; i.

Or -

check ormoneyorderto NICE,NiP.

Circle No. 1 on Free Information Card

mina!

""g (AP;(bdoschese%ncd7ii:9°°'

ale nq

Computers °^d

b 'ond 550-2 s and 555-2 s and our new "-As-. Our prices ore or least Si 3 less Mon any bono-fide advertised pnce in this mogozinefor the Sanyo 550 series. Of course pnce isn a the only reason we ve sold more 550s than any other U S dealer. f o find out whythese under $1.0003 MS-DOS machines ore the best computer value ct 1984 coil or write for our new 12 -page Sanyo brochure A

11,111811185 L

We have thelowest prices for

Sanyo550's/555's*

ColumbiaStill much more compoributy for much less money! Eochsystem includes MS-DOS. CP/M-86. km.3 Perfect WriterSpeller Colc ond Alec Fast Graphs Space CommandersHome Accountant Plus o tutorial. and nationwide Dell andHowell serulce.(prIcesindude color video cords keyboards128K dual drives ond mare).1600-1V $1899 VP's $18991600-4V (swith 10 Megabres) $3239

Scottsdale Systemsud.617 N. Scottsdale Rood Suite B Scottsdale ArizonD 85257

CX-C) (602) 941-5856Coll 8-5 Mon. -Fri.

L We penetrate in arbitration for business and customers though the Better Busieess 80(.1, A

COMPUTERSSanyo 1150 $1495Sanyo 4050 $1995Zenith 151-52 $2244Altos 586-20 $5925

PRINTERSGemini 10X $258Radix 15 callMT Spirit 80 $298Okidota 92 $180 off ListOkidoto 93 NEW

LOW PRICEEpson callToshiba 1351 $1339loki 6100 $418Silver Reed 550 $498NEC 3530 $1279Diablo 630 $1669

SERVICE/ORDERINGTELEMARKETING ONLY: If you plan to visit please con first for an appointment Prices listed are for cosh and include 3%discount. We sell ono Net 30 basis to Fortune 1200 companies and universines. No C.O.D.'s or A.P.O. s. P.O.'s add 2%. Viso.Mastercard odd 3%. Az. residents odd 6%. Prices wbject to change. product subject to availobility. Personal/company checkstake 3 weeks to dear. All Items listed ore new with manufacturers wonanty. 0-20% restocking fee for returned merchondise.Shipping extra -products are f.o.b. point of shipment. Software Is not wonontied for suitability. Registered trademarks.Televideo.Televideo Systems. Inc Unix -AT&T Technologies Inc

September 1984 107

Key CharacteristicVery low power consumption

Typical values at 1 MHz/5 VGate 1 mWCounter 3 mW8 -bit Micro 5 mW4K RAM 20 mW

Very low standby currentFor example: 16K CMOSRAM: 151.4A/3 V/70°CHigh noise immunityFor -example: 1.5 V atVDD = 5 VWide temperature range:Plastic: -40 to +85°CCeramic: -55 to +125't

CMOS Technology(Continued from page 75)

lar-level performance with the power,voltage range, temperature range, andnoise -margin enhancements of CMOS.RCA, for example, has developed a spe-cial TTL-compatible CMOS family toprovide pin -for -pin and functional re-placements for all of its TTL functions.The basic family is intended primarilyfor new all-CMOS designs.

Summarized in Table II are the keyparameters of CMOS. NMOS. and

est versions run at clock frequencies of 5MHz, compared to the 3.2 MHz of theCDP1802A. Higher clock frequenciescan be expected in the very near future.

The second trend is improvements insemiconductor processing, which allowa larger number of system functions tobe incorporated on a single chip. For ex-ample, the CDP1804A contains 2Kbytes of read-only memory (ROM), 64bytes of random-access memory

TABLE I-CMOS BENEFITSBenefit

(a) Low power supply cost(b) No cooling fans (lower cost/small size)(c) Battery operation/standby/portable

Allows backup storage with small/low-cost battery

Operates reliably in noisy environmentswithout special filtering(e.g. process controllersReliable operation in hostile conditions(e.g., automotive, engine control, military)

LSTTL. The speed enhancement madepossible by new processing advance-ments gives CMOS a substantial advan-tage against the other devices.

A Complete FamilyWhile CMOS logic gradually over-

takes TTL, the advantages of the tech-nology are also continuing to make animpact on microprocessor and memoryICs. As the chip density of NMOS de-vices increased, the heat due to powerdissipation increased. This forced the in-dustry toward CMOS because, althoughits speed compares favorably withNMOS, its power requirements are farless, thus reducing on -chip heat to an ac-ceptable level.

What is even more important is thatcertain CMOS processors (the 80086and 80088 for example) can maintaintheir internal registers and data valueswith the clock stopped. This means thatsystem current demands are greatly re-duced, thus increasing battery life.

When CMOS is specified for peripher-al devices, a power saving of 50:1 can beexpected. A power saving of 5:1 can beexpected when using CMOS memories.The first 8 -bit CMOS processor, theCDP1802, was introduced by RCA in1976.

The family tree shown in Fig. 3 tracesthe evolution of a typical "family" ofCMOS microprocessors (in this case, theCDP1800 series) Two trends are evi-dent. First, the speed of CMOS micro-processors is steadily increasing. The lat-

(RAM), and a timer/counter circuit, inaddition to the basic microprocessorfunction elements.

Since users obtain all the power, tem-perature, and noise -margin benefits as-sociated with CMOS technology, thesemicroprocessors can be applied in equip-ment in which it may be extremely diffi-cult to use either a bipolar or an NMOSprocessor.

As microprocessor -based systems be-come more memory -intensive, the needfor high -density, low -power memory de-vices increases.

Since a static RAM requires far lesscontrol circuitry than dynamic RAM,most CMOS technology advances arebeing made in this area.

Low -power CMOS EEPROMs (elec-trically erasable PROM) have lowerpower dissipation, better noise immuni-ty, and better temperature insensitivitythan their NMOS counterparts. Theyare making inroads in the "permanent"memory area as used in battery -poweredportable computers.

These two types of memory chips areprojected to undergo the largest growthincreases of any memory devices be-tween now and 1990.

Because the basic storage cell of a

108

RAM is more complex (thus occupyingmore chip area) than that of a ROM, to-tal storage capacity of RAM chips ismuch smaller than for ROMs. Atpresent, static RAMs are commonlyavailable in 16K -bit sizes, though 64K -bit chips are appearing now. By compar-ison, per -chip ROM storage can be aslarge as 256K bits, or four times the ca-pacity of RAMs.

However, dynamic RAM is not dead.Since a dynamic RAM requires a lowernumber of system clocks to operate, thishelps to reduce the chip power require-ment and improves operating speed. Be-cause of the reduced area required by dy-namic memory cells, 256K RAMs arecurrently available. New CMOS technol-ogy has also increased speed to a cycletime of 120 nanoseconds, also allowing adata cycle time of 65 ns, resulting in a databandwidth of approximately 16.5 MHz.

Users can look forward to two trendsin memory technology. The first is thatdensities (number of bits per chip) willcontinue to increase. Just as important,the speed of memory devices continuesto increase. These two developments,compared to NMOS technology for stat-ic RAMs, are plotted in Fig. 4.

A complete system requires supportdevices to transfer data between the pro-cessor and memory, handle input/out-put (I/O) functions, perform timingfunctions, and other so-called house-keeping chores. A wide range of periph-eral chips is available in CMOS technol-ogy to support the microprocessor andmemory.

Manufacturers are producing a broadvariety of CMOS chips such as keyboardinterface devices, interrupt controllers,real-time clocks, UARTs (universalasynchronous receiver/transmitters),and video controllers, among others.These and other devices permit design-ers to construct systems by assemblingbuilding blocks of fully compatiblecomponents.

View Down the RoadFrom the foregoing, it is obvious that

the decade of the 1980s and beyondholds great promise for CMOS-andoffshoot-technology. Because of its in-herent characteristics, CMOS technol-ogy stands on the doorstep of technologyleadership across the broad range of in-tegrated circuits. 0

TABLE II-CMOS CHARACTERISTICS

Gate delayPower (F/F at 1 MHz)Noise immunityTemperature range (commercial)Supply tolerance

ypeLSTTL NMOS CMOS8 ns 8ns 8ns

20 mW 8 mW 2 mW0.4 V 0.4 V 1.5 V

-40 to +85°C -40 to +85°C -55 to +125°C±0.25 V ±0.25 V 3-18 V

IBM rIPN,,11

FURNAL

PGRADING A PC. TO AN 'EXTRA r

NISRICS PLAN *OM

REAL TIME ANALYSIS OF SIMPLE DIGITAL.LOGIC CIRCI'rri

GI IDE TI) I SING THE IBM GAME ADAPTER

uVI Ili TIPS MR IMPROVING DOCI:MENTATkr.01.1!EMIL: PROLOk DISK AND SOFTSARE PIRAC1

LET'S TALK EXPERT -TO -EXPERTPC TECH JOURNAL, the only magazine written for sophisticated

IBM PC users...talks with you expert to expert!Do you require a magazine that provides you with theinsight and knowledge to act as your silent partnerwhen developing new programs? Have you needed toconsult with authorities in telecommunications toresolve a nagging problem? Wouldn't asecond opinion about connecting yourPC to a main-frame be helpful? With yoursubscription to PC TECH JOURNAL,you're harnessing experts in your field...experts who will talk to you in the lan-guage you understand, about the con-cerns you have...EXPERT TO EXPERT!

PC TECH JOURNAL is the techno-logically sophisticated magazine writtenfor experts in the field of personal com-puting like yourself ...discussing the con-cerns experts have ...developing elegantprogramming methodologies only expertscan understand...covering the wholefield of IBM PC's with thought -provokingarticles on communications, distributedprocessing, office automation, network-ing and programming.

Subscribe today and save up to 36% off the fullsubscription price, and have PC TECH JOURNALdelivered to your home or office every month! FromOne Expert to Another: subscribe today!

rTE IGHJOURNAL

I want to communicate with other experts and professionals aboutIBM PC's and compatible machines! Please enter my subscription

to PC TECH JOURNAL for:

0 One year (12 issues) 0 Two years for 0 Three years forfor $24.97-SAVE 17%! $43.97-SAVE 27%! $57.97-SAVE 36%!

P.O. Box 2966, Boulder, Colorado 80322 TJ8Z003

Mr./Mrs./Ms

Company

Address_

City State ZipSayings based on full one-year subscription price of $29.97

Check one: 0 Payment enclosed. 0 Bill me later.Charge my: 0 American Express 0 Visa 0 MasterCard

please pnnt name in full

Card No Fxp DateAdd $12 a year in Canada and all other foreign countries. Please allow 30 to 60 days for delivery of first issue.

Xerox PARC(Continued from page 78)

lot of people adopted ideas from PARC.Apple just put enough money behind itand invested in driving its cost down tosomething everybody could afford."

Charles Simonyi also admits thatcompanies like Microsoft, where heworks, and even the entire industry owesa lot to PARC. He credits PARC's con-tribution not to how unique the scien-tists were but to the special circum-stances they were given. "Other peoplehave held the same dream but didn'thave the freedom to develop it in a lab-oratory." Now he prefers to speak aboutthe present: "What's going on now is alot more exciting. The innovations thatwere once introduced by academics andat facilities like PARC now come fromthe industry."

New PARCsPARC not only inspired new prod-

ucts and new ideas; it also has spawnedsimilar environments at other compa-nies. Steve Jobs, Apple chairman andcofounder, visited PARC in 1979 andwas inspired enough to invest in the Lisaand Mac technology. In the publicitythat accompanied the debuts of these

PRINTERSQUALITY BRANDS......DISCOUNT PRICES

ANADEK BROTHER C-ITOH EPSON JUKI OKIDATA SMITH -CORONA TOSHIBA TRANSTAR

CALL OR WRITE FOR THE PRINTER& PRICE TO MEET YOUR NEEDS:

YOUR SATISFACTIONGUARANTEED.

CRAFTSMANCORPORATION

3116 BAY to BAY - BOX 18966TAMPA. FL 33679

813/831-5681IN FLORIDA

ALL OTHERS 1-800-237-4044VIM & MASTERCARD AC t I Pi D

Circle No. 7 on Free Information Card

products, he acknowledged his debt toPARC and its impact on Apple prod-ucts. He has also collected formerPARC employees, including LarryTesler, who went to work at Apple in1980 and Alan Kay, who arrived by anindirect route. After his years at PARC,Kay went first to Atari, where his jobmeant "politicking, keeping my finger inthe dike and following my nose." Evenas a chief scientist at Atari, Kay had ahard time trying to rationalize the needfor basic computer research. The "beancounters," as he likes to call accoun-tants, had the final word. At Apple hecan expect a difference, especially be-cause Jobs seems eager to resurrect themagic of Xerox PARC in developing itsnewest line of 32 -bit machines.

New Gardeners at PARCThe golden age at PARC officially

ended when a new research managemententered and Bob Taylor left last. Othershad taken their leaves in the late 1970swhen corporate headquarters in Stam-ford, Connecticut, took a more active in-terest in PARC operations. Scientists atPARC started to feel pressed to make

their work more relevant to the Xeroxbottom line. In the spring of 1983 Xeroxappointed a new PARC director, Wil-liam Spencer, a Bell Labs veteran who isparticularly oriented in turning the labtoward the marketplace.

Taylor hasn't retired. He, with mem-bers of the original PARC team, is in theprocess of establishing a new computerresearch facility in Palo Alto, with an-other corporate parent, DEC (DigitalEquipment Corporation).

Though details are few, it appears thatDEC, a company that has a solid stand-ing in personal computers and is well -en-trenched as the minicomputer leader,needs the ideas that only a think tank ex-pert and talent collector like Taylor canoffer.

While Taylor is relunctant to talkabout a center that isn't even completelybuilt, he did put the new DEC center andPARC in a long perspective: "If you'regoing to try and connect the present withthe past, I would suggest going back tothe ARPA days. The whole thing hasbeen a continuum. PARC is not any-thing special in that continuum. It wasjust a midway point." 0

Put Professional Knowledge and a

COLLEGE DEGREEin your Electronics Career through

wenel

Earn Your

DEGREENo commuting to class. Study at yourown pace, while you continue yourpresent job. Learn from Granthameasy -to -understand lessons, with helpfrom your home -study instructors.

You can earn your B. S. Degree inthe Grantham electronics degree pro-gram, offered by independent homestudy and accredited by the NHSCAccrediting Commission.

Our free bulletin gives details. Writefor Bulletin E-84.

Grantham College of Eng]neerinc2500 So. LaCienega Blvd.

P. 0. Box 35499Los Angeles, California 90035

CALCULATOR SAVINGS

pa HEWLETTPACKARD

HP -11C Pogram,aiste 564 99HP.12C Pump,* 99 99HP.15C Programmable 99 99HP -16C Hetradeornat 99 99HP411CV Alone P.eymb 189 99

HP-41CX Enna Fun In 259 99821049 Card Reader82143A Printer82153A Wand

4999299 9999 99

HP.97 beak Progrmb 599 9982169A HP -113 Inert< 359 99

82400A Card Reader Call824019 HP.IL Interim.. 107 9982420A 46 Mem for 718. 59 99HP -75C Computer..... 699 99HP -75C, Computer ... 929 9982700A 8K Mem for 75. 149 99

nil

82160A HP -IL Module 599 99821619 Cassette Dove 359 99821629 HP -IL Printer . 359 99821649 RS 232 Interlc 249 9992198A 80 col Video Int 269 997470A HP -IL Plotter 899 99821809 band Functns 59 9982181A band Memory 59 99821829 Time Module 599922258 Think Jet Pr 419 99HP 41 System Case 4999Port Tender to 10 pis t 29 99

Call lor Low Prices on all Accsesorlas and Softwere

TI 01-66 Advanced Programmable. 500 stepsMSS Student &weld CalculateTS55-11 Stunts Calculate */ StatutesLCO-Prograrnm.e Hellidean1411 COAV110,1994i Business Analyst FinancialBA -55 Advanced Handheld Faunae,

559 9919 99

34 9959 99

36 9949 99

Ow, EL -7050 4 -Color Graphwriter 579.99EL -7001 Memowriter 3999EL -7100 Deluxe Memowriter 8999EL -550 Printing Handheld Scientific 29.99EL -5500T Handheld Computer/Calculator 79 99CE -126P Cassette Interface/Printer for 5500 84 99EL -70501 Factory refurbished 39 99EL -700111 Factory refurbished 29 99EL -71008 Factory refurbished 39 99EL -550R Factory refurbished 19 99PC -1500/A ROM Software Modules 49 99

Cada FX-70OP Handheld Computer,1568 steps .. 55999FA -3 Cassette Adapter for FX-700P 34 99FP -12 20 -column printer for FX-700P . 59 99FX-96 Credit card Solar Scientific Calculator 24 99FX.450 Scientific Calculator with Hexadecimal 29 99FX-720P Expendable Handheld Computer 79.99FX.750P Emendable 4X Handheld Cornpueer 109.99

SL -1103 Film Cara 2299

Beleeleseediedi. NMI Fames soler.VSA. et IOC. etre stole We ave awlsleer. Aleseeppies Pi 1 el perm& PlIMMrailm10111011...., 50CA - W IA MOW* ealekety USA ericaORDER 800-421-5188 Outside

TOLL -FREE mimeo. II,. 12131 en= CA AK. Hi

Tam's Inc, Dept CE14932 Garfield Ave.Paramount, CA 90723(213) 633-3262to

Circle No. 42 on Free Information Card

RATED #1 FOR SERVICE & REUABILITY

Symphony(Continued from page 50)

the virtues of its predecessor. One fea-ture that has been enhanced over the 1-2-3 implementation is the ability to freezeentries on the screen. You can freezerows at the top and/or columns at theleft borders of the window, which is par-ticularly useful in a large worksheetwhere it is difficult to remember whichdata is in a particular row or column.

GraphicsSymphony breaks little new ground

with its graphics capabilities. Availableformats are line graphs, bar graphs,stacked bar charts, pie charts, explodedpie charts, and high -low graphs. The lat-ter two graph types are not available in1-2-3. All of the normal capabilities oflabeling, creating titles, shading or cross-hatching, and scaling are found inSymphony.

The thing that is new in Symphony -and in some of its competitors -is theability to display on the screen simulta-neously the data and the graph. This isparticularly useful because you can dy-namically see the effects of changing adata element on a graph. Unfortunately,it is not possible to print graphs with textother than labels and titles.

Symphony can dis-play data and graphs

simultaneously

DatabasesA Symphony database is a specific or-

ganization of a worksheet. Each columnof the worksheet contains a field in thedatabase. The first row of the worksheetcontains the field names; each row there-after contains one data record. You en-ter data one record (row) at a time. Theadvantage of using the database formatover a spreadsheet is it gives you the abil-ity to set up forms for data entry. Youcan customize a form to give informa-tion about the item to be entered and to'do edit checks on the entries. Data entryforms can be set up so that entry clerkssee only the parts of the database rele-vant to them. For example, a managercould set up a payroll database with mul-tiple data entry forms -one for enteringconfidential information about an em-ployee (e.g., the hourly rate) and one fora clerk to enter the number of hoursworked. Since each field in a record isreally a cell in a spreadsheet, fields canalso be calculated using all the powerthat is normally available in a spread-sheet. In the case of the payroll database,an employee's weekly wage could be cal -

CALL TOLL FREE

800-221-8180IN NEW YORK STATE

CALL 1212/ 732 8600

COMMODORE 64dim.111.

64. RAMV,04041 $19995COMPAOCIORE 64 SOFTWARE

C00.00049MT'""CODn"5r14.5. Me DarSMARM Ramon

KCQrwetx r= er1AMa"

`1410'243911'NMse.os`U.

ACCT. 50010*le

14.95MARI 30.1 Pole Position '30.10rAP Tpl M P marl '19.95

COMM000.1 M. Niacnine `141.99AuTMATOD Sumer C.A, 1,14.95AUTOMAT., MR.. ADO. ORM.AuTOIRATIO 01000.i14.93NM C.I. MM. '19.CO...ROOM. Mna, '1495

94_n5095

'5900'CIA11="TIRA IMMO. '3493C0.1.30009 MAU 61 `31113C0.141000.114004 AMC liarsCOM.00049 OM 7 7 M 95COMM000114 Mpt Oe14 ' M.99CO...000119:wo x.95CO.0.000115 Amender MN ',it.SCARSOMUCA narterhor '3495COM11000. Co., 39 95CONmalirte nom mn 44 95SOMA nommorti 39 95Mr11.116 Faun. Cleacie 109 95

RA, ARTS Cut a. earn 34 95C0.9.000. Marla Fortran 9 95COMOODOM Tr. Mont 17 95COM4000. Gem. 0.9. '54 115COMA000. inventor',

`MR

,000n 3r on (Ma Am e 4,11

COW LAD Cam Lee Rene AM 11M45ircon

MOOMAS41101011 AcnewTION

193101110MA A 6.4 Is

ICNALIONI125 232

ATM 103011C 011103

.1110 99

529 95

,29 95

FLOPPY DISKSmom um 001191AMMee3419 10COMM lion .enatrnoKosr. OtOrtantCA. BAY 20'O 105 01)5 yo,Ot 110.6014 9111.1.9 19.91/10011.1.1.91. VAT.. MOSSO11). MON.Man. SCCern Nnell 11205

We NO Von A- Om

rinmac

APPIUS1CWORLD,23 PARK ROWNEW YORK CITY,NEW YORK10032

THIS MONTHS SUPERSPECIALS

APP. RRr cot co, Lofts. AM,OR -CMPRAM. ROI PM .1. ORMA CON, RCM CAM CAN MOWORVILL1.01.11.11256 2 0 DIMIS V.IDOG*000 81, RAO, SPV.77111.95vwvoMICSS5 19,21}595

APPLE CCWAPATEUIDISK SOFTW1. ARE

Tknw /one 54 959111.1. WMarti Ana Pomp. 19NP00010 Dead.. 29 15ROCCO. 1110 24 15!MOM .9111 SmAator 11 5495MKT ARDS One on One 21950091111 Ortss 44.141111.11.11. Temple of MP. }495

1900aTMsonMom Porn oPalMl

COmmerra nom Anne.. 'N 15SCARSDROW, MrtertneSOMA nemmon2 Om 1195M.R.O. SA r SOAR CCM. 0x6Stn. 0000Mem Scommll. 114115

..9 eV IN.D. 1 3 `94.15

CI

,11 'CALL0 OVVF

ta,,E0 CAll

}29595

IBM PC COMPATIBLEDISK SOFTWARE

Samon MenP.M°. Plan...(TAMA Mister 0, Ow Doren5MAT.MC Tigers ,n vowSTRAIIMC

Waro Pace.TA. SO,

IPX600.6.11.11101.5 S

Msteerroe9.1.53

.1.1111.1 1CIS 1.0.19.0

ELECT ARTS C. a PaneMM. DATA TOM.. analran, 10

39107995)495)9 DS79 9579

.

[*150 wadable and In STOCII APPle. ladle. ISO and5an70 computer SOftentS Call IOC IOwest

29 95

;;; TZ

;:: 1Z5195

- FREE GIANT CATALOGSCALL TOLL FREE 800426-6027

288 PAGE AUDIO VIDEO COMPUTER CATALOG 64 PAGE RECORD AND CASSETTE CATALOG

80 PACE VIDEO MOVE CATALOG

23 PARK ROW, Dept. CE9 NYC, NY 10038....... -0 ......, ........ . ...v.- ,,,ous MOWS, SE. MONET

,..15....i, 5 :c 0.4511RCARD MA DAM' COO143eaton Me AM POnanee. PONT MMUS( PER. - . ' CCItS W. CLEAR CM M. WORE .CCE,53PIC $311

.,..,111 n35.'r,,. gra ..v-nt.,,,,-;.,I,17 5,-6,137.4.14A,17;WO NO CANZ WAY Cana.. 10e01 A0.1 II . RADOM n ,' ' 95nummn mem For 1.11.M.A,DEWY One. Mese Ow 2.- 501.NO C 0 0 NM +Ow .5.00,0' V .215 ,Of all 1111.14.4.1M.. EIRAND MY PAMIR" MO 100, GUARY101110 WE oin KOTINSPONSIll POR My erPOCRAMICAL MOOS

*TAR, BOO X LAND 1050 DiSx DRIVE SPECIAL'

grill11111$49995

ATARI SOFTWAREFenlin A wan.

.0Aro roustPat..

rAle. Ropornan 70114ATARI Pat Aran,C1=.MM. Poke MM.ATM Donkey 1.9AUTOMATIC Pint. '24.95ACTIVM. Ave R. '24 95ACTeMM 1.9.aments '14 115DTONLATIO Gateway AM. 0,24 95avan Town 14131. 'finSMARM Omen.. 1 D.

...1.53.311CA110114ATARI Atanwrher 111 95

SCM Mr/ 2 '19 95AMOR01.101 meter... '74.113

ATARI 10004010 Rapc a -Ann.,. 95ATARI ON.1,111.9 '19 95TAR1 MIMIC - '139 93MAIN PM Md.. 5410'ATM Mr. Meng n/02000 " ISWO

AriONALO PIMP Moollier 74 VS

ADMINTIM INTIMAdam Graprm MN. 21.91/009....... Dn. emcee 39 115

PRINTERS

34San31 955210'32.5'San'3495

279 95ATM 1021 - 279951. 01520 ". 14ARSON 1.01. w.95

ATlM OIovenAr

2695lCM MRO 5411mn.IN

DISK DRIVES205 95

NC 01541 229 95NW 1000 27095

149 95

Mae Ulna 2 . 00,349 950*. ATM CT A Cm,. 93

MONITORSCOMMONS 01702 0 co.,. '210 115TAM. 1030 12 up, sue, 0195ablalIONIC 11.130 Ceeen '10.10PAILMONC 9911001) ,3 RCA 'MI 113MOM 1000 simmer Scom.141195MOM Ann 12 ArrOl. sC fIC `1111 93TAM. 415 Pre in.- iTes '479 95

WRITE or CALL for FREE 288 PAGE AUDIO 'VIDEO /COMPUTER CATALOG

Circle No. 23 on Free Information Card

kcx)t

PERSONAL CIO_SUPPORT

"

CATALOG

Please send me a tree

copy Cl Inmac'sPersonal ComputerSupport Catalog.

Inmac Catalog Dept.2465 Augustine DriveSanta Clara, CA 95051

NAME

COMPANY

Inmac makes it

easy to make yourCuter work harder.

comproducts,

Chooseirom over

1500 p

all speciallyselected to helutep you

get more out of your compaper,r.

Orre-step shoppieg.P

connectors,cables, more.

Many ex-

clusive lnmac products,too.

Essg erderiaq.Mail, phone

or

Verbal P 0:s welcome.

Loser shipping costs- All 9

Inmac distributioncenters re

fullystocked, so your

order can be

shipped fromthe nearest

centll

er.

re-

45.14945.149riskireetriaL Fu

fund it not completelysatisfied.

Guaranteedquality. Most

guaranteedfor one year, some

guaranteed forhie.

1-800-547.5444:

NM

ADDRESS

CITY

STATE ZIP PHONE

In California, call 1-800-547-5447 for your free catalog. 23510

Circle No. 10 on Free information CardSeptember 1984

DEVICESPERSONAL DEFENSE AND PROPERTY PROTECTION

13 UTILIZE SPACE AGE TECHNOLOGY.LA CAUTION THESE DEVICES CAN BE HAZARDOUS AND MAY SOONI'1 BE ILLEGALA POCKET PAIN FIELD GENERATOR - IPGSO

SAssembled559 50

IPG5 Plans $7 00 IPGSK Kit/Plans $39 500 PHASOR PAIN FIELD CROWD CONTROLLER - PPF10

RAssembled $250 00ppFi Plans $1500 PPFIK Kit/Plans $175.00

S BLASTER- Provides a plasma discharge capable of puncturing,i canBLS10 Assembled $79.50BLS1 Plans $1000 BLSIK Kit/Plans. $59.50SHOCKER/PARALYZING DEVICE - Very intimidating andeffectiveSHG60 Assembled $99 50SHG6 Plans sto oo SHG6 Kit/Plans $79.50RUBY LASER RAY GUN - Intense viable red beam burns and

L gelds hardest of metals MAY BE HAZARDOUS.

Pro -31:r Available-1ZSiatttlN:GcIALZapro.S duces a continuous beam °thigh energy MAY BE HAZARDOUS.

1gtfansvailiC°mf_ifin! Device00E4BlAsE:Ll:HGt4pr estenserabamfor

p sighting. spotting, etc Hand held complete,..- LGU3 Plans $1000 (Kit A Assembled Units Available)S IR PULSED LASER RIFLE - Produces 15-30 watt infra -red

pulses at 200 2000 per secLRG3 All Parts A Diodes Available 31000BEGINNERS LOW POWER VISIBLE LASER - Choice ofred, yellow, green - provides an excellent source of monochromaticlightLHC2 Plans $5 00 LHC2K Kit $29 50

, SNOOPER PHONE - Allows user to call his premises and listen0 n without phone ever tingingE SNP20 Assembled $89 50,.. SNP2 Plans $9 00 SNP2K Plans/Kit $59 50C LONG RANGE WIRELESS MIKE - Miniature device clearlyU transmits well over one mile Super sensitive, powerful

R mFT1viIRELESSPlansTELEPHONES700 PAFTITTEPRians/iKriatnsiThStrboSt1

I vyr,Zspoit.ip5hone cpolaminsersa hos% over ,crine mmileirutspioahn:lult(otmaticall

334T TALK it TELL AUTOMATIC TELEPHONE RECORDINGY DEVICE - Great for monitoring telephone use

TAT20 Assembled $24 50TAT2 Plans $5 00 TAT2K Plans/K.! $14.50

IOur phone is open for orders anytime Technicians are available 9-11a m . Mon-Thurs for those needing assistance or information Sendtor tree catalog of hundreds more similar devices Send check. cash.MO Visa. MC. COO to INFORMATION UNLIMITED!- H' 91 P 0 Bcx 716 Amherst. N H 03031 Tel 603-6714730

TheMean Little Kit

New compact 24 -piece kit of electronic toolsfor engineers, scientists, technicians,students, executives. Includes 7 sizesscrewdrivers, adjustable wrench, 2 pairpliers, wire stripper, knife, alignment tool,stainless rule, hex -key set, scissors, 2 flex-ible files, burnisher, miniature solderingiron, solder aid, coil of solder and desolder-ing braid. Highest quality padded zippercase, 6 x 9 x 13/4" inside. Satisfactionguaranteed. Send check, company purchaseorder or charge Visa or Mastercharge. Wepay the shipping charges.JTK-6 Tool KIt $95.00

Free Catalog!Page after page of hard -to -find precision toolsAlso contains completeline of tool kits and toolcases. Send for your freecopy today!

.7! p' I r

7.,* Mil I

-

JENSEN TOOLS INC.7815 South 48th St., Phoenix, AZ 85040Phone: 602-968-6241 TW X:910-950-0115

Symphony

culated by means of the spreadsheet.Once you have created the database,

you can extract information in the for-mat you specify. For example, from thepayroll database you could extract a listof employees who worked more than 40hours in a week. Capabilities exist withinSymphony for ordering the database en-tries (sorting) based on any field and forreport generation. Because of the inte-grated nature of Symphony, you can setup a form letter using the word process-ing facility and insert the names and ad-dresses from a database. You can controlthe order in which the letters are printed,e g . alphabetical or lip code order.

Symphony isa worthy contender

in the integratedsoftware

competition

CommunicationsSymphony includes a means of ex-

changing information with other com-puters. The communications package in-cludes facilities for storing phonenumbers and automatic log -in proce-dures. You can also define settings suchas auto -dial or auto -answer for yourmodem. Using the communicationspackage of Symphony you can have thePC act like a "dumb" terminal to amainframe computer. I found it relative-ly easy to emulate a VT100, call a VAXcomputer and run a program to extractsome data, capture the data directly intoa Symphony spreadsheet and graph it.

Add-on ApplicationsWith Symphony you can access other

applications and return to the sameplace within your Symphony session. Atthis time two such applications havebeen implemented, DOS and the Sym-phony tutorial. I was able to exit to DOSfrom a Symphony spreadsheet work ses-sion, create a print file using Supercalc,and return to Symphony. This capabilitywill permit Lotus and others to expandSymphony to include new applications.For example, Lotus plans to marketspelling -checker and appointment calen-dar add-ons by the end of this year.

Importing Data from OtherPrograms

After some manipulation I was able totake a file created using Supercalc andimport it into Symphony. I found that itwas advantageous to separate the text

and the numbers into separate files be-fore importing the information. Sym-phony was unable, however, to importnumbers with imbedded commas prop-erly. I could not, of course, import theformulas for calculation; I had to re-en-ter them using the spreadsheet facilitiesof Symphony. Importing a text file fromanother word processor was relativelyeasy.

Symphony also provides a translationutility for dBASE -II and Visicalc files.The translation utility works bothways-that is, you can import files intoSymphony or export files from Sympho-ny to the other programs. Symphonywill work without translation on 1-2-3files, except that you first must renamefiles with a different file type.

Conenand LanguageOne place where Lotus has made im-

provements to 1-2-3 is in macros. Oftenyou find that you are repeating the sameseries of keystrokes over and over again.Within Symphony you can create a mac-ro by using the Learn facility to Teachthe keystrokes to the computer. Whenyou invoke the macro, the same series ofkeystrokes will be repeatedautomatically.

Lotus has applied the concept of amacro to more complex sets of prob-lems. For example, Lotus claims thatyou can develop your own menus, simi-lar to the ones used in Symphony, buttailored to your particular application.Thus you might create a database appli-cation to catalog the items in your homefor insurance purposes and create com-mands such as Newltem, Deleteltem,Revaluel tem.

Symphony provides a language ofmore than 80 commands. Evaluating thelanguage, which includes arithmetic,logical (including decision -making),string and statistical functions, is beyondthe scope of this review.

ConclusionSymphony is a eery powerful system

whose particular strength lies in its com-plete integration of its various facilities.It is a worthy contender in the integratedsoftware competition. If you do a lot ofspreadsheet work and would like to beable to be able to incorporate text withtables and charts, then this may be thepackage for you. I wish that it includeddynamic reformatting in the word pro-cessing module and did not require theuse of two disks to start the system (inorder to include the Help facility). In apackage of this complexity and magni-tude, however, these are very smallannoyances.

Circle No. 8 on Free information Card112 Computers & Electronics

Computer Scientist(Continued from page 31)

can learn a great deal about the flexibili-ty and power of analog computers bysimulating a simple machine with thehelp of any personal computer havinganalog joystick ports.

Suitable computers include RadioShack's TRS-80 Color Computer, theApple Ile and the IBM PC family. Con-sider, for example, the PCjr, a machinehaving two analog joystick ports. Eachport supports two potentiometers andtwo on -off switches. Therefore, a simpleanalog control panel having four poten-tiometers and four switches can heconstructed.

In Part 2 of this column, I'll describehow to assemble such a panel fromreadily available parts. In the meantime,you can easily experiment with an ana-log input for your computer by using itsjoysticks as analog input devices.

For example, the listing that followsconverts the PCjr into an analog inputmachine that provides the sum, differ-ence, product and quotient of any twojoystick values:

10 'PCjr ANALOG COMPUTERSIMULATOR

20 CLS30 X=STICK (0):Y=STICK(1)40 LOCATE 6,1550 PRINT "X ="X;"Y =";Y60 LOCATE 8,1570 PRINT "XY =";XY80 LOCATE 10,1590 PRINT "X/Y =";X/Y100 LOCATE 12,15110 PRINT "X+Y =";X+Y120 LOCATE 14,15130 PRINT "X -Y =";X -Y140 GOTO 30

Though this program is specificallydesigned for the PCjr, it can be easilyadapted for use with any other machinehaving joystick inputs. When the pro-gram is run, the monitor displays a tableshowing the current joystick values (Xand Y) and the results of the four basicarithmetic operations. Here's the tablethat was displayed when the joystickhandle was moved to a random position:

X = 110 Y = 78XY = 8580X/Y = 1.410256 -02X+Y = 188X -Y = 32

Many other arithmetic operations andother enhancements can be added to thisbasic program: The X and Y values canhe variables in an equation that is plottedon the display. Moving the joystick tochange the variables would then almost

simultaneously alter the shape of theplotted curve. Similarly, the X and Yvalues can be used to set, via the joystick,the aspect ratio of an ellipse having afixed diameter, as in this PCjr listing:

40 CIRCLE (160,94),20X/Y

50 CLS60 GOTO 30

When this routine is entered and run,05 'PCjr VARIABLE ASPECT a flashing blue ellipse or circle appears.

RATIO ELLIPSE Moving the joystick's handle changes10 CLS the aspect ratio of the ellipse.20 SCREEN 1,0 Finally, a second joystick can be add -30 X=STICK(0):Y=STICK(11 (Continued on page 114)

a4. a10.Bee m ""1 77-77M-- ; \Xel- _-".",- _

N.

lab

7\t Jr"-

1984 Mail Order Catalog

The One Stop Electronic Shop!Call Toll FREE 1-800-343-0874

In the United States:Mail OrdersP.O. Box 8000Westborough, Mass.01581(Mass) (617) 366-0500

In Canada:Montreal5651 Rue FerrierMontreal, QuebecH4P 1N1(514) 731-7441

Ottawa1023 Merivale RoadOttawa. OntarioK1Z 6A6(613) 728-7900

Boston133 Flanders RoadWestborough. Mass.01581(617) 366-9684

Seattle13107 Northup WayBellevue. Wash.98004(206) 881-8191

Downsview86 St. Regis Cr. N.Downsview. OntarioM3J 1Y8(416) 630-0400Vancouver3070 KingswayVancouver, B.C.V5R 5J7

(604) 438-3321

Visit your nearest Active store, call, write or circlethe Reader Service Card for your copy of Active's new catalog.

Toronto14 Carltor StreetToronto. OntarioM5B 1K5(416) 977-7692

Calgary3220 -5th Ave. N.E.Bay 2Calgary. AlbertaT2A 5N1(403) 235-5300

pt t. m her 1984 Circle No. 50 on Free Information Card 113

*REDUCES DISKETTECOST 50%!

Make use of the backof your 51 4" Diskettesand SAVE NAME IN1TCH tools

make it easy Adds the precise

notch where you need it Doubles diskette space

or MONEY BACK

MILE NITCN 1Cuts square notch forApple, II, II , Ile, Ill,

) Franklin and Commodore/ only $14.95 each

add $1 50 each PAH ($4 50 each foreign PAH)

NAME INITC1 NCuts square notch and ''4" inch round"index hole " For use with computers

other than those shown above

only $21.90 eachadd $2 50 each PAH ($6 50 each foreign PAH)

SATISFACTION GUARANTEED OR YOUR MONEY BACK

'Florida Residents Add 5% Sales Tax'ORDER TODAY!CALL TOLL FREE 1-000-642-2536 aqsA

OR SEND CHECK CA MONEY ORDER TO MINN

NIBBLE ATIITCH11011111/TI ie ITINNICTS

DIVISION OF CORTRAN INTERNATIONAL

4211 NW 75th TERRACE, DEPT. 8 3LAUDERHILL, FL 33319

PAT PEND All 114111,F MARKS APE ACKNOWLEDGED

Circle No. 5 on Free Information Card

WHAT...WHEN...HOW.For Home or Business

LEARN HOWTO USE A

COMPUTERTrain at home in spare time! Noprevious experience needed! Nowyou can learn it all! Com-puter programming...compu-ter applications...computergames...everything you everwanted to know about corn-, puter operations! Write yourown computer programs oruse hundreds of programs

-""") already available...budget-ing, real estate, bookkeep-ing, expenses, investments,

interest, taxes, shoppinglists, vacation planning,addresses. phone num-

bers, routing ...evenforeign languages and

graphics.You'll know what really happens when you have a computerproblem with a bank, store, loan company, oil company.utility or anyone else. You'll be able to talk theirlanguage understand why and how things happen tobe able to take the offensive when you're the victim of acomputer error. Experts explain everthing in easy -to -under-stand language with step-by-step directions. Computerincluded with your training plugs into your TV.

SEND FOR FREE FACTS!

rICS COMPUTER TRAINING. Dept. PD084Sa,tl ,i19. Scranton. Pennsylvania 18515

I Rush me ree facts that tell how I can learn corn -I puter appl cations, programming and operation atI home in spare time. No cost. No obligation

IName Age

Address

I City/Stale/Zip

1 one No. including area code (

Computer Scientist(Continued from page 113)

ed to provide a total of four variables. Ifthe joysticks are equipped with triggerbuttons, from two to four user -selectablestatus conditions or preprogrammed nu-merical values can be inserted into themix of available options.

In Part 2 I'll describe various ways tomake and use a simple analog controlpanel for a personal computer. I'll alsodescribe the surprisingly simple archi-tecture of a futuristic, single -chipanalog/digital microcomputer.

For more details about do-it-yourselfsimple analog computer circuits, see the"Experimenter's Corner" columns inthe January and February 1979 issuesof Popular Electronics. Both have beenreprinted in The Forrest Mims CircuitScrapbook (McGraw-Hill, 1983).

Stearns(Continued from page 43)

On the other hand, many PC DOScompilers, assemblers and interpretersworked without problem. Lotus 1-2-3only needs a small patch provided byStearns to work properly. Software thatuses the high-level interface to DOS, in-cluding many of the popular data pro-cessing packages, will run without anyproblems.

PerformanceIn several benchmark tests, I com-

pared the Stearns with the IBM PC -XT:floppy disk, hard disk, CPU speed, and acombination of these. I was interested inthe effect of the faster clock speed andthe 16 -bit data bus. I found the Stearnsto be roughly 2.5 times faster than theIBM XT, except in floppy disk applica-tions, in which it was 1.5 times faster.

SummaryThe Stearns is a well-built machine of-

fering a substantial performance im-provement over the IBM PC and manyother computers that are compatiblewith the IBM. The programmable key-board and function key display on line26 of the monitor enhance its perfor-mance and set it apart from thecompetition.

Potential buyers will have to weighperformance against compatibility andavailability of software. The companydoes intend to market compatible ver-sions of popular software packagesthrough its dealers.

Without a doubt, this machine is well -suited both for word processing and dataprocessing, especially where speed is es-sential. This computer is a strong entryin the field of IBM PC compatibles andis well worth considering. 0

GAMEBOOKS

FROMCREATIVE

COMPUTING

BASIC COMPUTER GAMES, Micro-computer Edition, edited by David H. Ahl.Here's a great collection of 101 fascinatinggames, all written in easy -to -use MicrosoftBASIC. Play Craps, Combat, Super StarTrek, Lunar LEM Rocket, Gomoko,Checkers, Boxing, Bowling -and 93others! With an introduction, notes onMicrosoft BASIC, and conversion instruc-tions for other BASICs, 8%"x 11", softcover,illustrated, with an index. 183 pp. $7.95($1.50) #6C

MORE BASIC COMPUTER GAMES,edited by David H. Ahl and Steve North.In this sequel to Basic Computer Gamesyou'll find 84 challenging new games,complete with sample runs, program list-ings and illustrations. All run in MicrosoftBASIC. Race your Ferrari, become a mil-lionaire, joust with a knight, crack a safe,and more! Conversion table to otherBASICs included. 8%" x 11", softcover, il-lustrated, 200 pp. $7.95 ($1.50) #6C2TRS-80 Microcomputer Edition, $7.95($1.50) =6C4TRS 4n r lr 11 irk k tdr. of

CREATIVE COMPUTING PRESS Dept NX6C39 East Hanover Avenui r iv Plains, New Jersey 07950

Send me the hook, it

ITEM PRICE P&IiM I 1115 I l l s. EACH I I TOTAL

I A. NJ and NY yr...Puts add pplicable sales le

(Inhofe I 'SA a d for regularpostage and handling per order

CHECK ONE:fl PAYMENT ENCLOSED $E CHARGE. MY:

E American Express E Masted'ard [1] Visa(Charge and phone orders $10 minimum.)

TI 1TAI

MP A'S. I

Card No

Mr Mrs. M

Address(please print full name)

Pap Date_

Apt

City

StateNW taster service. CALL TOLL FREE: 800-631-8112.

tin NJ call 201-540-0445

I_ Also available at your local bookstore or computer store

Commodore ProModem 1200 FiberopticsRS232 ADAPTER FOR

VIC-20 AND COMMODORE 64

de:e411

The JE232CM allows connection of standard sane! RS232printers modems etc to your VIC-20 and C-64 A 4 -poleswitch allows the inversion of the 4 control lines. Com-plete installation and operation instructions included Plugs into User Port Provides Standard RS2 3 2 signallevels Uses 6 signals (Transmit, Receive, Clear to Send.Request to Send. Data Terminal Ready Data Set Ready)

JE232CM $39.95

PROMETHEUS

Intelligent 300/1200 BaudTelephone Modem with

Real Time Clock/CalendarThe ProModem' Ise Bell 212A 1300//200 baud) intelli-gent stand-alone modem Full featured expandablemodem Standard features include Auto Answer andAuto Dial, Help Commands. Programmable IntelligentDialing. Touch Tone and Pulse Dialing More Hayescommand set compatible plus an additional extendedcommand set Shown w alphanumeric display option

PM1200 $375.00KEYBOARDS

VOICE SYNTHESIZERFOR APPLE AND COMMODORE

N\M/

0.8t112011

JE520AP

JE520CM

Over 250 word vocabulary -affixes allow the formation al morethan 500 words Built-in amplifier speaker volume control andaudio lack Recreates a clear natural male voice Rug -in userready with documentation and sample software Case size

x 3'.. 'W 1-3/8'11

APPLICATIONS Security Warning Telecommunication Teaching Handicap Aid Instrumentation Games

The JE 520 VOICE SYNTHESIZER will plug right into yourcomputer and allow you to enhance almost any applica-tion Utilizing National Semiconductor's DIGITALKER Speech Processor IC (with four custom memory chips),the JE520 compresses natural speech into digital mem-ory, including the original inflections and emphases Theresult is an extremely clear, natural vocalization.Per, No Clear notoon Price

JE520CM For Commodore 64 & VIC 20 $114.95JE520AP For Apple II II. and Ile S149 95

JE664 EPROM PROGRAMMER8K to 64K EPROMS - 24 & 28 Pin Packages

Coreiver, Sall{aelmed - biome Na Memel SyStael lo *rem

Em uuros PROms moms RS232C pule, novas n nol liyspogrom Meckna nada data m10 OMAS ftyPosfd Charges /fold n HAMby keyboard Loads ran an EPROM Compares EPROMs liar Lontoni0Worowes Cmws EPROM* Pr.. input iSvAC 60H. ANA awn IOWW., consumption 6 ncbsurs Color coordonated Mehl tan panels henmooed end puns on noftha doom Sae IftLn BA D it MightSi Its.in..16641,41A1 Swam.w p.n.s.s ma oINAInA ram m I.M1666...^

Bt nervy (bosh it moIMESM s norm NOI Be IWO o miwways fl Son a liNo !POW son aossInna amp. na Mar. ISM RuthRP do non its pesos KAMM ors 1.4 We mar be Aussie Imam oftoomnon We iota, WV rasa meoefamfor fteramolft ernM/Pro nvlNH simn to mom*, change ft metier a vegan foam,. Aron OAPs

an. coreftnneof oAkty 10 a. I froft Mom atereeng unuwasarassanin ft RAWM Daewoo. An weft muss*, of IN pas, ft 1664 dossdays DAIS AM

*BIM, in ram.* IMAantrwri Wm DISRAv Into. DAMnoon ire MCA melon Morn fAhl ..or lo MOON ova of 5 0, am 55a

sa. r v o nonay oft Inn Mont.. ...sap:mount cOnAm.o nos ow SW. Jumper One. NOM Pow

JE664-A nieneset $995.00Asiammaci I 'mew ancloNrs MICA ModWer

5565 - 13232C IRMO - Ina RirrIX (Ave. engem.

%To tar woe. n ex tau o -no oy ,,, ..1. ,kx o,FOR A LIMITED TIME A SAMPLE OF SOFTWARE WRITTEN IN BASIC FORTHE MS -80. 1.100El i /1 ye r N COMPUTER WILL ALSO BE PROVIDED

JE664-ARS ERIN Pres was Ipso. ... . $1195.00Annemtani 4 i "led andel= JIA 16A Mono.,

EPROM JUMPER ketOLISES - Palselloft MRS WSW Wow., Abe am n apus A goo. Ira ea- aft ...JEW It WIMP. pqraverma Noma WI EPROMawofereaws lea ItRAN =Pet cmediala le Ml 4444Ar61011

/me MI en MO = MOM IIIIMMIMP _ RIMAIN WM

SAM /rte Tr AW. Stelwaa 1w nial 11__

loseRIM 2/16 Naafis" nit ft oaint ft le.c to

OM .. tior.- PERM aft W WI, III MM. n pan

Man MAP Re lemft Ol Moak lell refmom MD 2* km hem NC Mae are

IMAM %ft PMALPS ?PM PM ken MI . SUM

AMA 10/ANSS Ps Weft MawWORM

age Pm ZIS we Notaas Ear _ AH16AAA MBAs ye .r.

13's x 4'. NV H

Mitsumi 54 -Key UnencodedMatrix All-Ptroose Keyboard SPST IteySentcne, 20 par ribbon cable coma,bon Low profile keys Features cursor controscontrol caps hock) function enter and shift keys Coke Ikeyclpal grey 1 lb Pinout mciuded

KB54 $14.95

New!

MasWignifeW& app a112 a 0051s a quadsma aral a BO

76 -Key Serial ASCII Keyboard Simple serial reVertaCre SPST mechanical sonic,tDB OPerates ir upper and lOwer Case Ft. uSlounction keys F 0-F5 Six linger edge Card connec-

tion Color (Maya) tan Weight 2 lbs Data inci

K976 $29.95

Nationally KnownManutactunerl

eft

EcifigeNie 222ar22

21's L 9 8 W H

106 -KEY 8 -BIT SERIAL ASCIIKEYBOARD- The terminals were designed to be daisy chainedaround a central host computer and used as Ind,ndual work statons - Hall effect Sketching numericand cursor keypad 10 user definable keys 50ontertace cable with 9-pn sub miniature connector

7 LED lunctioo displays' Security lock N key roll-over Automatic key repeat function Color icaselwhite wiblack panel - Ikey caps, grey and blue Weight Ei.o lbs Data included

KB139 $59.95

68 -Key Keyboard with NumericKeypad fcr Apple II and II+ Plugs rec into Apple II or II motherboard wily16 pin ribbon cable connector 26 special lunc Ions Color keys) while/grey Weight 2 lbsKB -A88 $89.95

POWER SUPPLIESTRANSACTION TECHNOLOGY, INC.5VDC 1 AMP Regulated Power Supply Output 5VDC A 10 amp (also 30VDC regulatedl Input I 15VAC 60 IN- "wo lone (black/beige) self enclosed case 6 lout 3 Conductor bla,kpower cord Sue 611 L W H Weight 3 lbs

P551194 ,,,, $14.95

Power/Mate Corp. REGULATED POWER SUPPLY input 105 125/210-250 VAC al 47-d3 Hz Line regulation 0 05% !Weemounting surtaces Ovenoltage protection UL recognized CSA certhedPert No WWI SIM Wm& MeeEMA5/66 5vet3A/6Vet2 5A 4:01 .4Wx 24-71 2 lb, $29.95EMAS/IIC 5VII6A/6Ve 5A 5%1. 441,44 2,11.1 4 lbs 1139.95

POWER SUPPLY 5VDC le 7.6 AMP.12YDC le 1 5 AMP SWYTCHINGnput t i5OC 50 BOW 3 arnw23011.0 5011. 6 amp Fan ow Doom swx/ir

moot sonlcries 15,230VAC Word 51.1SC 7 6 amp OVOC e s ant, 8 Mir .comsat cad Sae Ital. I 13SIS 31/411 Wsmnt 6 ips

PS94VOS $39.95

KEPCO/TDK 4 -OUTPUT SWITCHING POWER SUPPLY ideal for disk drive needs of CRT terminals, microcomputers andvideo games Input 1 15,230VAC 50,60H7 Output 5V ft 5 Amp 1 2v

8 Amp 12V et 2 Amp -120 ,3 5 Arne UL recognized CSA cerified Sue 7%1 6 3116W x % Weight 2 ibs

MRM 174KF $59.95

POWER PAC INC. REGU_ATED POWER SUPPLY Perfect for computer systems Output 5VDC in 11 Amps 5VDC 0 1 Amp 12VDC a 2 Amps 12VDC 0 ti 5 Amp and 24VDC 0 3 Amps Overontage Protection Size 12%1 essAY Isiti Weight 17 lbs Speq nci

PS2922 $69.95

;The EDU-LINK Learning Kit

The EDU-LINK fiber optic systemis a low-cost, TTL compatible data

:. transmission system designedspecifically as an educational toolfor students and engineers work-ing in many different industriesIncludes transmitter PCB a re-ceiver PCB, one meter of plasticoptic fiber. and all the necessary

electrical hardware Complete step-by-step instructionstheory of operation and tutorial information are included

ELK -1 ONLY $19.95APPLE ACCESSORIES

514 APPLE "Direct Plug -In

Compatible Disk Driveand Controller Card

The ADD -514 Disk Drive usesShugart SA390 mechanics 1430formatted storage 35 tracks Compatible with Apple Control-ler 8 ACC -I Controller The drive

comes complete with connector and cable - lust pluginto your disk controller card Size 6L x 3'7 W x8-9,1613 Weight 4'7 lbsADD -514 (Disk Drive) $195.95ACC -1 (Controller Card) $ 59.95Also Available...JE864 ISO Col 64K RAM for 'lel $124.95JE614 INumeric/Aux Keypad for Ile) $89.95F051APC (Apple Cornpat '7 -Ht Drivel.... $209.95

LI r.i.rr..5iiiiES Protect Yourself...ma. DATASHIELD

awe Surge Protector100 El.mmaleS voltage spikes and EMIRF I noise

DO.. It can damage your equipment Oh causedata loss 6 month warranty Power dissipa-tion 1100 mcroseconds) 1.000.000 waits 6

ON e sockets 6 foot power cord Normal line von11' 00 age indicator light Brown out/black out reset

switch Weight 2 lbs

Model 100 $69.95

Protect DATASHIELDveunwi- Back -Up

Power Sourceell

Provides up to 30 minutes of continuous 170VAC 60117 power to your computer systemdoad dependent' when you have a black outor voltage sag Output rating 200 wefts Si.month warranty Weight 24 Ms

Model 200 (PC200) $349.95

For more demanding systems (e.g. with hard disks) Output rating 300 wattsXT300 $489.95

IBM MEMORY EXPANSION KITCOMPAQ COMPATIBILITY

4 -CHANNEL SWITCHING POWER SUPPLY Microprocessor mini computer. terminal. medical equipment and processcontrol applications Input 90 130VAC. 47-440Hz Output 5VDC Or 5A-5VDC a A 12VDC ex 12VOC I A Line regulations 0 2ok Ripple30mV p -p Load regulator - lw Ovorcurrent protection AO 511 mainoutput 10% Size t IN a 415i16-1 Weight 1'0 Ms

FCS-804A. $89.95 each

Switching Power Supply for APPLE II, II+ 8 Can drive lour floppy disk drives and up to eight expansion cards Short circuit and overload protection Fits inside Apple computer Fully regulated 5V 5A, 12V e 1 5A, -5V 5A -12V 5A Direct plug-in power cord included Size L 3'7'W fa H

Weight 2 lbsKHP4007 $79.95

SAVE HUNDREDS OF $$$ BY UPGRADINGMEMORY BOARDS YOURSELF!

Most of the popular memory Deere. allow you to add en srldPonslMS QM( 1112N. Of 2916 The 115645 All will popuists Mese boardson UP byte Increment* The kit is Simple to - lust insert the

M 640 RAM chips in the provost., SoCIIS and 11111. two groupsof stanches Directions are included

IBM64K (Nine 200ns 64K RAMO $49.95

TRS-80 MEMORY EXPANSION KITTRS.80 to 18K, 32K, or 48K

Model 1 From OK to 15K Requires (1) One KRModel 3 = From 4K to OK Requires (3) Three KitsColor = From 4K to 161( Requires (II One Kit

111oNti aPLYPOWS room. dma oo is MY raw ...V.05 ft avowed tef urn I IR al

TRS161(3 '200nt for Color Model IllTRS-151(4 '250ns for Model I

912 95

51095

TRS-80 Color 32K or 64K Conversion Kit

510.00 Minimum Order - U.S. Funds OnlyCalifornia Residents Add 61/4% Sales TaxShipping - Add 5% plus $1 .50 InsuranceSend S.A.S.E. for Monthly Sales Flyer!

Spec Sheets - 30s eachSend $1.00 Postage for yourFREE 1914 JAMECO CATALOGPrices Subject to Change

ELECTRONICSVISA*

1355 SHOREWAY ROAD, BELMONT, CA 94002Ws 9/84 PHONE ORDERS WELCOME -1415)5924097 Telex: 176043

Easy to install kits comes corn pie% with Bea 4164-2(200ns, 6410dynamic RAMS and con...own documentation Conveys TRS- 60'old co pales MOE ET F and NC circuit boards to 32KAl so converts TRS-60 CONN computer II to 64K Flea DOS or 0S-9reihnred to utilize lull 64K RAM on all computersTFIS-64K2 544.95

UV -EPROM Eraser9 Chips - 51 Minutes I

LI Chip - 37 Minutes

Etssos 2101,2716. 2732. 1/114. 1516 2531.1564 Erases up to 11 chipsWenn 51 minutes it chop on 31 minuleal COnStnt ftostordlatence of one non Spec., cOnduCtim foam how eliminates staticbuildup Built on laft lo p UV a fposure Compaq- Onla00. 3 ro a 2 GO' Compiata with holding tray Ion a chips

DE -4 UV EPROM Eraser 579.95UVS-11EL Replacement Bulb $16.9.501

September1984Circle No. 21 on Free Information Card 115

DIGI-KEYC O R P O R A T I O N,

VISA

IN 4119

NATIONAL SEMICONDUCTOR PANASONIC DUALITY - Name brand products from nationally recognized manufacturers. CHEMICALS ARIES PLESSEY MOLEX EAAVIO CHEMWIK ATLANTIC DIODES N wkcnINE DIAMOND TOOL. UNGAR GL CHARIES PLESSEY MOLEX AAVIO E lP _It

OK MACHINE UNGAR GC CHEMICALS ASERVICE - Computerized order processing and inventory control AS INSTRUMENTS D -E Al. PRODUCTS. WI

/ND TOOL UNGAR GC CHEMICALS ARIESNATIONAL SEMICONDUCTOR PANASONIC SAVINGS - Volume Discounts OEM Quantity Pricing Toll Free 800 Number CHEMICALS ARIES PLESSEY MOLEX E I

I i II V.G, at Or r al 00101 0 V I i 1 V 010

mm..1 0 Fr 1011 sir Cocoeo II. 0101 DIGO 0/1 - 0031 NOV 9.100.0 if IV poi.f V 010, 11, 0/01 X - 91 / 7 - CPI / - 101/I 1- /

INTEGRATE -IT CIRCUITS If Pol.. 1,1,,,taro er vvenono is NOS CMOS ..

Im 043017.11shooS

to.

a1 X aoo

MOM5514TH P 1043041.4 1 14 MI611)0131111 -WPM 1.0 130140. 0143.:at= A--LIMN Kr. =

vono. ,110trona:: t=

3., tlt:mt: 1/PAP 10 yTayiyi ia awe1.4/10110 a 10/01001 1021113119 ..0017R 6 17

2.0701.0 In "'""n" 21.1711102 .

01.0171 X 21.1701.11.51711410.6000 1 13

131032052 60 02103100 12 =al

1 13 011141.1040 1 133012.302).

513010. 6 I1 SO 031901.161, 4

1101/101 1 55.yomv, WPM. 40KM. 0113401 110

16111000N 1 31101004 375 -

11.4. .01003 1 CO a -

SOP 4 14 r1,;11100

r31N.J., ' : AN.1.11364 27 =WPC 011, 60.10

;003.012 : :14.7Z0133,2 2IP. 100 IMOMOM 1 0 Pot Pro .0.61,003EC 6 112 ,....... 0

ON0.1340C12 110 0040.561. 2 0 PM

1.1010. 16 1 02 ,........ it.0.0400 COPP s , 0032.00302 1

52 00047.. a.m. . c,,,, . .r.,..

NAMPA n c 00,,,, y, ... InvooN1o4 TT canoe, ... ::-.03411 2 77 ... IP

0400111

111 r .0.0.6. .0. . 4. 106 1.110s

;110004 3: 0101401'4 if v; -1.', ;100 ;: : :',...

2164340. 10 1110"..... : ]::21.4... -1-1) 070. 1 sl I: m,,. 7o I.3. 010 241.0

00212 3: 1,49055. . .. . :; : 10 3 304 2/0aVOX 2111 3 - 315

.1.0010,4 2 01 1,000...' :?: 1: 6 1 417 430 3 02 31.263. 64 0,21.2.t. 4 la 014 310 -

is.1779 20 N.' 4 PK - Pa 3001.14100 3,6 ..- . ..44 12 610 - 0 la 4112 430 -

2103706 6 1O

:4.100 1110 0112 Mit -

t 0 6.

4022.240144

4011.4070840710

001.0 343 .4112111

21.3114 T .G004.01104 I 03

26130,4 Iiii031. 1 .043.303. 1 V I.1:10rr. ajjar

oo PM 0. a.. 1004.11. f.- 2015. 11.0 POPP.1430, 202 XaQtW

3191 01.0.0.1 0511110,.'.7.00.5-0 91 Man Pp ......001.1102486.9 1 01 ;.=1.6,0106 104

7.312.94100,6 -1 111107.1,4451110.87C9 100471106 2 33 'Mt24101110. 654021144430211.1;;;:3: -L,::-.00.9 P1810OMO 6 431

10111110 6

0006 14

13100.7004VIII= -LH

41101 01 WM.111001 10 P.2571. 43

tr1;:e9 . 1.11163111.604 03 4.01066061111,

.....001% 114 a. PC00611.113

7461. .2 42 .0317CCA , 121013010 a

0.10C1001CCor

PC11210633.01111C00 l7740CP11000 127 24061000001CPu .430.

0.31 .3006vin 241246020 .441/6

134021011.012 17 2.400101001002061108010122C10 0

103,20410

a4...00C10222CP

0.1181001.121211/4 211,

11.112121.1401 62.210.

0.0000. =160039

..190241

0.000'5.2674.42000

tr.6 0 OD

=7'

51040.... at 6.1.6 no. w6291 10.0.1

I h. II,: 1 1 .1 A11 ,,

NT

I.C. SOCKETS

2.1111121

.. 70 Over, try.n romps co. PPM 13.106...64 ...MP 11 Pa.

aAiicDd

24 r PP 09. I 0 9 1 02 AO P Sao1 10 III Y b. Na41112 63°I 12 . 10 010 2a -411.

3 12 110 OM la 11.0 >6.., 13 120 1 1.2 102 - 022..

31.1

641

264

C.41,400041.

v 400001151411. Of .0.1.1530C01.008

SOLDER TAILDIP SOCKETS .

.001.1 C.O./ 1006 04 0010.

121 01.110.1104.0111 ro

ten ft 0.. 0 0.CAKE 110.10.6.1. In 13 1 lb Alaalll Id 2. bolder aca 15 1 12 000116 111. on 17 1 00 1300

20 1 .0 I, 00CM, 6.16.1... on n 2 10 2000C21 32 on la

2100CON po moan ta. 311 3 10 4 00COO 31....10.0 to 33 .0 2, 00OP Ow, 61 40. 30 amMal NOM SOY. TM or

Dol.= I It INCOX swam ram 34 3 20 30 00C.1214 24102011.1. 141 geld 44 4 20 00one 1....oplo tad m.60 4 70 moo.

91P 1,W. 51 5 40 02 0020 No.. 0.1 013 IP 600 67 0022 ....121.a. 061 GOO 00

o a. g. 71 701 A 00

. ,

WIRE WRAP -DIP SOCKETS

mar.... I

0.00.4 4400111.4*04 I

416 4111- No.mai M... 1.010

OM ammo D. go No p.m NW ow 061. NM. ol Mr'

.00 C140.134 IP 00 IMP00

3.-- o.n.o... -10.3.10.11111100011 .1111

1.1 RAMP MINN WW1,. ......11.gyt 1 12 0.

21201.0110.1.11 111. 30 34 al000 1.1.0. amp. an V/ 410 1000PPM IG0nP .40 . 6, 110, 00011. 0. 1010.. 0A 03 00alb 206. . AI 7 10 0001122 21, wrap 0 830 BallOWN 01.1.....ap an III SW 06 00CNN po 0.30 an 101 1030 00

010 orap on 0 1320 In 00

PPPON

1.10100 8 00 PP.. OP 6.MI 114 14I1 000

361 903116 14pnoo.140 10 0

ono ro un0134 0 no .040 1

041 10. 031011 Y. C1111011111111 011.6.1.2101. ....)121110111111 op,. 2. m.*. 024a 0140 40 0.a 0.6. 704

" 17:7707r L. "W SO mom. 1. PM as.0

NM No .110041.10 MOP. 41.00104.111

t6. I 2 26.2. 110.1.. 9.SA pant la IP 2 3116 (

.50 "PO 72.0.0 1 1 11 10.10l 20 24. lo 9100 al.a/06.

516 law PO 006... pm 0. rpm.. pa .0pr .an P.m" 0 MO at 1001..Oaa 11.231 0001.6310 1(10613 00 111122X 30012130 POPP CO

M 13 a 0' oo

MU MO IMO UM IPA MOO PM 03 0 000 4601.011.41300 046

.00 1340 41140 1110.0 1400 1.42S 14 74..

Ono. Ir. X. co. Misch

124

21:: rig /1

LICON RECTIFIERS

1

. loo,10

now'

06.100

41. 1841 a IN 5ii.PION 9041 IN 00 1.10 22 H.,22,222,

1 2.222 2.21 or 7 a

. MINN 041 101. MINN COW Iw

6.113003 NC 160 033

3Si' fSICOfl RECTY II R

A

110 3110144. 44.8 In 1 110 12

1011 0101100, a ann.1001 AlmNa. 14.0. 33 1,0 241010 A. 1010 IS, 0 25 3 .-11006111 Sp 0.0 0401. 33 2 4 51

ROMMOO

104

Silicon I ransestoys

TEXAS INSTRUMENEDGEBOARD CONNECTORS

11111.11

' .. ..

...24

'XI i22'1°,.'; iiII:

1. y

: ; If 27 GO .2:

23 .2 20

000 10

63 M

114171111111-141-....-SINIESOARD CONNECTORS

v. r.%?..610 2 113

0.11 4 70 4'

Oa MIS 3W

M 6 03CO23 3 W

D ON 4 XCM SO PIO OM

tl 1.310 0.110 92031 6 0 NA 631 b AC311 1110 11131 S

131311

040WM CM 66110 .411 70

*13 0.10

144 At 51113 1Dr iMrEDOMOARD coralecToRls::: =fp

10 4 33 42 C310 2111 X4111IS 0 20 0 50 C3 16 3 40 no

c a 6 03 12 33 C3 3 70 1020 600 S7 10 .20 3 011 in

04 II GA 00 10 .22 4 20 010US GO, MD C3211 ,11

am

C41. 71, OR 02. 404C 03 PO 47 70 C331 4 0031 1 10 70 0 31 615 LIT:C21. 20 ON .10C4X .30 .;; ,

0.304 7: 44 20'110

H4 5.111211.0.01304110 CONINCTORS

CI 10 2 06 C3 i0 4 11CI 12 210CI 16 303 MA nm"3514

Cl It 6

c' A

614 05

as

, ,

2000

so ,ii 121 V OU 113

10, 1e

DISC CAPACITORS

NEWltur400

DISC0, a cPACTTORS CAT. MO09 KIT

03595 ... .... 14" P.,..:7:::." oftue gaup ...mama W...Panasonic LS Serials

111/112 21,171,111111, 241.1111.21.1. 1114222. NWr ml

211 V.11

2 5.

11 Pa ...NPO TYPf nem 10 3 6

a ii 0410 04

SE

0-rt C

13 311 1311

;33 IN

u :II3114' mii=

60417TN 3fA

t' 101

OM,

$540

'r-.1; 74 4 IA 4

a

IL 10

Fr? "; 1::

10 110 46 31 13:3 111101 :r 11

3114 ,,,ii 3104 o Y 041 .a

,131406 114 ie

0 0 4. 1. 6 1000.30 Um 1.0.001 4.3 11 3I 4: ...............,................. m, 3

ii, . ,,I, :.. 0 . 0A to u s lo ;az 1

n 97 14 KM

r5 IT. oi: "7" ,--7,1 if '

10 -,e91..: .E

r,;1 1-no14 0 WO 6 0 .23 :op OD 4 40

: 110 1410 11 411 0 SOO

0 0 PKO P S43by SOO 6 43110

320 o, SOO

SID . SOD

TO at SOD

AO 0 P00 0 WO

00 0 00010 01 101

%to* 101di 4 10000 000

o 6 .0 1/1 0,: P 7: .0,,

,sso .,mos, ,ss

:"°X.16,1 I:OpIT

14.101 POI MO .0 XOLIN .

iF.' 1 I! 1 I II al, -:

140104

21, 1 al 36 I 1'4" I 1: ,,: 111007 of X

: 3 mmens=sem xi_ a- it 1'1: 1::"am 1: = L''', ''' ' g''' a 1 II :a a: al:

, '1 3 NI : r, la a: ***NM 32 of SW 3,

431 a1,DM 1 03 :: :: A 3 1. E.4.11 emoo.". :: .0 37 11. 003 ....

0400.1 : I :13" M. i i Si II an !I.:"

.a.m.. an cm.. esIN IN Zs;.... NM 0 0 KO In on 10 A w. 44; 14411 0 0 no ro 17 IS 73, 163 MN

. 0.1 Mew OnF II sin- '.0P91202 SO

NEW.. KITCat NO

.2070 0 11 10 31 2 12 SO . 0o11371 0 47

110

39 is 311 32 20.4 IP

LIF: °I:

:a : 11 2 if: tiao02,2,12

i V2

..2.22211222. 2 2 03 IMOpopy

ii ..: is :: I: t:

0111.71:41.0.."." PO SI PO 0 117:54'1111%

plop :: : . !2,2: I:.---- -,.........,...... .,.... I. 1111 10111

l':';: 1 - 1 ril 3'.=:.1901 KO 1 23

19.

:7: ; El 17' 33 33 Al.ii 3:

PANASONIC V SERIES

'5

1.001 MI 11 SI 11.11.

MO 0 012 11 SI51103 0 016 11 111 ;LI :ION 0 ON 11 WMO_ ONO 11 0 42

1002/ 11 0

MO"' : NO** '1 ;: P.NOD 0 OW II 31

er F.. VPIO OOP II1.0.11 OMNI II 0 7U V a`NMI 0010 11 7U .NM 001 11 r V*1100 0012 11 01 000 1119010 0014_ 11 10 007 01 6

MN 0018 II 101 0 03 /MO O. 12 If II IS 0 611141618 02/ 0 In 11111 /0 n10510 on n anMP 0031 1,1 120 10 /I

141121 OOP 16 132 1131 VA.MX 010 14 1 12X 2./110 001 0 1U 13 19 1S 1404 000 IS 1 NO 102 ;

NUB 0 I IS 1U 14 NO NM 012 20 101 110 113 0PP 010 X 221 1000 13120KO X 211 ,.m 0120AIM DX 27 142 10 00010 0 /7 10_ _204 3 33 1

N1131 ea 33 3 CO 21 71 Or SOOW 0 30 N 3 33 NW al 20160133 0 0, 3 AI 1011 134 03PP ON 4 X UN 261 01

rmislef dour

0101 oil 0. 011 0001 01I 0101 1 0101 011 POI 01.

TAMISOMIC 11910 NELLMCAPACITORS

NE KIT

43

6 43W1

0 PI 2 71 10 10 110 141,10

961 13--L3

ua x1103 11 I 0001.159II

3%." "6 01 MO a w O is 141014 0*

;a 3: 2.:101

I --

AA

13 7.11

wowpNo.

: :: ::'''10 lap ;3 . .. 44 62 0101..: '.AO 1 5

I: 12 10 43110

in 100 1. 01 1:0 33 :3:-,..

"' '''' 1.' : ;; : 16.111 ..".305 110

Iv: .'

tmY

3 0 ,4 14-7 160431.1 NO 100 2,

24 0 203 A 1033102, 10, Al .0 4.

10 T1

ran217 111

'301:

MN MO

112 '"110no::: no E ii ,: 3: 2:000 0man aN myInn nO on

:a. g

: ii ilei ''''1.113300310 2.0 ON 19 : ::2073 no 007 19,03 AO OW II

.03MO PI7/0 an

ra. nonO

3 - '' ill. * Ili 3:.1 210 : '' .0 20 73 1.11

1.0nono so

rz i iri Ili 303 41IAA330 17

21 na

222no

m II ::: AMP CHAMP20, 33132 33 CONNECTORS

no 4 04 41 13 TO 13 C

1.11 :.al ' ' : is

r: Ci 14.1.0 Let Tor 017:400 11.010MDIM: 218 ii .: j: :: . T. :4101- 34- Cablac........1-li 1.14-

noAN

:: il If Lilo ;.0 022 3440

2.3 1,1 ..332 34 I C4040.111.40

503 36 0 CM. 1.003 103P311

OT2

.410.1 ..033'' ' i: ::P (10

., 1: ::37: 400 ON

144:

:: ::::,.;ma or

moma :: re:

3 36 31030 3182

AI. 2

21212 : 41.20111.212* -2 igSU

43040OM : 3 1.1 :r, ...

. tin4 113 ....

PC 11.4100. I01 0. : 0 601 41731., Bawd mg ,. GINPC 06.110.4 a... In

47

113 U If. 01o il rit 15a1914

.2017. 10201

P1011112 111 140101'2 I o:

3 '3 310010

;2, Er cr.

Panasonic TSW Seriesloge AMmomm Imhelp Copoeders

10.10 Up* 0.MO4 1120.1 141 I 14 111.

MOO I. O. WM 4 ONMNIMO

MD ,r 11 sol co

141101110 110 1473 0300

MUNIP 20 0 10 147 inNM 20 lea 177 00

MO 35 308 r a ion moomr. an IN 1101 IOWMO/ 001 10 MS Ulm140100

.n. as es 1730

1111110

IOU 321 34 0 U3 MWM 4.14 31 D1 317 03

01411 311 MU I. 7 06 71 02

11.4

alln IN ionMn0013

0110008** :.: 111: MCC

1.14...41. 2.11:

MnMIS

10 1033

PO lm 140 /DC:WO PO 2 a /OM 16003MO 4703 3

09121 0O3111 MOD

MI CO

41102 10 470 : 7:MP KM IC 11101

VIPM. MO 351 36.11

10Za, 01 10 133 30PUN 330 115 not Nla 02rQr411. 3U 31 0.1 2. 00

PI 1.0 1. ;334000 230 302 22 a 210110

1031 4A 310 Dm 210

006 31 N 1.4.901,10.1 00. X A C00300041110.10, 0 UMW. ,1.020 K For. Sant Iva MI

00en 0.

400

01,KO

e.4.21 CO 1:

14149

CAT NO3060P Ka

OPAI$3515

Latch Type Connectors

]A1 1U3.0381

00.0 10 00.1101 IN 410 IM001114004en rm.Iro N San 14.0 14 13.41 Arum onIna 141 Sam Mb DO1510 X 641.6. 9101

004 11.;c.1;.---tvIn e Hr. No 004y, a .0

0U

MOUNTING HARDWARE AVAILABLESEPARATELY.

CHARGES VOLUME DISCOUNTAdd 12.00 4 0.00.4 99.99 NETAdd 310.73 S 100.00.4249.99 Lass 10,Add 50.10 S 2E0.00.1499.99 Less 15%Add 00123 1 300.00.4999.99 Lass 20%No Ch... 41000.00 II Up Lass 23.

Ina 0.8 key .4041 2.000nt 0110 ,ery.ce chapel a, ornphy to apply Mon owns sod by INg. Key may be yomb.ned ler a .012071120(10011 !terns flat are not d.ycoantobk. are tdentoloed by the..01.4 ND Iollow.ng the port number Alter we.% your order total all of the d.scountoble enn and apply the owopoote discount To ,ha me:dotal cad the non Ascoonlabk arms Then oddthe 1181410 (Nei* R. Pay all sloop% pod .nsotonce to addresses ,n the U S (onodo and Nlexeo *hen cheek a money cvde, ac. 011)1111111 ord.,

11 10.00.423.00GINIERYsi ET MINN. EYE: 1.60346.1144 IN.. M., N., NE 114.1141.411741 ti meN Nei pm wiry OPEICIT. Rbpboyee If Sega, INN SITor Pao. NI S6791 2E00149.99

100 may pay by clonk many order. Master (harp* VISA p C O 0 0/01 -KEY GUARANTEE: Any pan 00 0000)101 punhosed Nom Dm. Key that prove to be defect.. rdl N. 4 30.00.199.99InRoced a vehey4.1 .1 11toened 0.1nn 90 days Irony 140497 rah a "my of your 1n10Ke 4100.00 0 Up

Circle No. 10 on Free Information Card

PARTIAL LISTING ONLY - PLEASE CALL OR WRITE FOR FREE CATALOG.

STATIC RAMS2114 1024 x 4 (450ns)2114.25 1024 x 4 (250ns)2114L.2 1024 x 4 (200ns) (LP)TMM2016.200 2048 x 8 (200ns)TMM2016.150 2048 x 8 (15Ons)TMM2016100 2048 x 8 (100ne)HM6116.4 2048 . 8 (200ns) (cmos)HM6116.3 2048 x 8 (15Ons)(cmos)HM6116LP-4 2048 . 8 (200ns) (cmos) (LP)HM6116LP.3 2048 x 8 (15Ons) (cmos) (LP)HM6264 8192 . 8 (15Ons)(cmos)

LP = Low Power

DYNAMIC RAMS4116 250 16384 . 1 (25Ons)4116200 16384 x 1 (200ns)4116150 16384 . 1 (15Ons)4164200 65536 x 1 (200ns) (5v)4164.150 65536 x 1 (15Ons) (5v)TMS 416415 65536. 1 (15Ons) (5v)

5v Single 5 volt supply

8/9.958/10.958113.95

4.154.956.154.754.955.956.95

39.95

8/7.958/12.958/14 95

5.956.958.95

EPROMS2708 1024 .6 (45Ons) 3.952716 2048 x 8 (450ns) (5v) 3.952716 1 2048 . 8 (350ns) (5v) 5.95TM52532 4096 . 8 (450ns) (50 5 952732 4096 x 8 1450ns) (5v) 4.952732250 4096 x 8 (250ns) (5v) 8.952732 200 4096 8 1200ns) (5v) 11.952732A 4096 . 8 (25Ons) (5v) (21vPGM) 9.952732A2 4096 . 8 (200ns) (5v) (21vPGM) 13.9527128 16384 .8 1300ns) (50 29 955v = Single 5volt supply 21vPGM = Program et 21 Volts

SPECTRONICS CORPORATIONEPROM ERASER PE 14. 9 chipcepacity 83 00

RESISTORS >t IC SOCKETS

80008039 5.958080 3.958085 4.958087 CALL8088 29.958155 6.958748 24.95

82008203 39.958205 3.508212 1.808216 1.758228 3.4982375 21 958243 4.458250 10.958251 4.498253 6.958253.5 7.958255 4.498255-5 5.258259 6.9082595 7.508275 29.958279 3958282 5.508284 5.508286 5 50

Z-80Z80 -CPU 3 95Z80 -P10 3.95Z80A CPU 4.49Z80A.CTC 4.95280APIO 4.49Z8OA S10/0 12.95Z800 -CPU

&CAAOUSIV650265226502A

680068026809E6821684568506883

4.956 956 95

7.9514 952.95

14 953 25

22.95

DISK CONTR1771 24 951791 24 951793 26.952791 54 952793 54.95

INTERFACE8T288T97DM8131DP830493349368

1 8989

2.952 292.503 95

CLOCK CHIPSMM5369 3.95MM58167 12 95MSM5832 3 95

DATA ACOADC0804 349ADC0809 4 49ADC0817 995

SOUND CHIPS76488 5 95

LAY3.8910 12.95

ORDER TOLL FREES. WATT 5% CARBONFILM ALL STANDARDVALUES FROM 1 OHM

TO 10 MEG OHM

50 PCS./VALUE .025100 PCS.NALUE .021000PCS.NALUE 015

1.99 1008 pin ST 13 11

14 pin ST 15 1216 pin ST 17 1318 pin ST 20 1820 pin ST 29 2722 pin ST .30 2724 pin ST 30 2728 ST 40 32

800-538-5000

009.7,M,S79pin40 pin ST 49 39

DIP 64 pin ST 4.25 callST = SOLDERTAIL

SWITCHES 8 pin WW .59 .494 POSITION5 POSITION6 POSITION7 POSITION8 POSITION

85

.9090

.9595

14 pin WW .69 .5216 pin WW 69 5818 pin WW 99 9020 pin WW 1.09 9822 pin WW 1.39 1.2824 pin WW 1.49 1.3528 pin WW 1 69 1.49

D -SUBMINIATURE CONNECTORS01109P Male 9 Pin D Sub 52.08DB25P Male 25 Pin D'Sub 2.50DB25S Female 25 Pin D Sub 3.25DB25SR Female 25 Pin Right Angle PC 4.42GREY HOOD for DB25 Connector5 1.25

MISC.ULN20033242

2.497.95

40 pin WW 1.99 180WW = WIREWRAP

16 pin ZIF 6.95 cell24 pin ZIF 7 95 call

1052610S34IC1550

IDC CONNECTORS26 Pin Ribbon Socket34 Pin Ribbon Socket50 Pin Ribbon Socket

2 433 154 65

MC3470 4.95 28 pin ZIF 8.95 cell IDE34 34 Pin Ribbon Edge Card 3 25AY5.1013 3.95 ZIF = TEXTOOL 101216 16 Male Pin Dip Plug 1 65COM8116 10.95 (Zero Insertion Force) RCS° 50 Conductor Ribbon Cable 1 38'

PERIPHERALSJDR HALF -HEIGHT DISK DRIVE TEAL. MECHANISM - DIFECT DRIVE 100'. APPLE COMPATIBLE- 35 TRACK 40 TRACK WHEN USED WITH OPTIONAL

CONTROLLER $1 6995 1 YEAR WARRANTY

40 TRACK CONTROLLER 54995

FD -35 FULL HEIGHT DISK DRIVE*MADE IN USA SHUGART MECHANISM* FULL 1 YEAR WARRANTY $17995

CONTROLLER FOR FD -35 $4995

BMX -80 60cps BiDirectional 5249"JDR 16K RAM CardPower Supply 4amp Model 54915

$3995

ill1224 S. Bascom Avenue, San Jose, CA 95128800-538-5000 800-662-6279 (CA)

(408) 995-5430 Telex 171-110

JUMBO LEDS1.99 100 up

RED 10 09GREEN 18 .15YELLOW 18 15

MOUNTING HARDWARE10 EA 1001.09 EA.

DISPLAYSMAN 72 CA.3 .99MAN 74 CC .3 .99FND 357 CC 375' 1 25FND.500 CC 5 1.49FND.507 CA.5 1.49

ELCOMPHardware HandbookMfr's Specs LOGIC,MEMORY. MPU s 8 more

800 p9. s1 4,s

lOpf22p127pf33pf47pf

50V. 056 EACHMONOLITHIC

.010 -mono 50V t4

.047uf.mono 50V 151 uf mono 50'V 1847uf.mono SCIV 25

ELECTROLYTICRADIAL

25V35V25V16V

AXIAL50V16V

CAPACITORSDISC

56pt82pf

10Opt220p10010

1uf4701

470022000

1uf22uf47u1

220u1 25V 30COMPUTER GRADE

44.000u1 30V 3.95

to

183060

.1414

JDR Microdevices

Copyright 1984 JDR Microdevices APPLE IS A TRADEMARK OF APPLE COMPUTER CC

CRYSTALS32.768 thz 1.95

1 0 mhz 3951.843; 3.952.0 2.952.4576 2.953.276 2.953.579E45 2 954.0 2.955.0 2.955.0688 2.956.0 2.956.144 2 958.0 2.95

10.0 2.9510.738E35 2.9514 31818 2.9515.0 2.9516.0 2.9517 430 2.9520.0 2 95

DISCRETEKBP02 Bridge 451N751 5.1v roofer .251N759 12v weer 252N2222 25PN2222 102N2905 502N2907 252N3055 792N3904 102N3906 101N4004 10/1001N4148 251100

LINEAR 1TL 084 2.19LM301 341.111307 45LM311 64LM3177 1.19LM319 1.251.111324 .59LP.1339 99LF351 .60LM353 1.00LM358 .69LM380 89LM386 .89L.111393 1.29IL497 3.25NE555 34NE558 1.50NE564 2.95LM565 .99LOA 566 1.49LM567 .89NE592 2 75

M723 49LM741 .35L PA 1303 1.95MC1408181.1111454LM1481L111148fX R2206XR2211CA314ELM3914751507515475188751897805T7808T7812T7815T7805K7812K78H05K7810578112790517912T79L0579L12

2 95.5969

.693.755 251.853.951 951.951.251.25

.75

.75

.75

.751.391 399.95

.6969858579

.79T = TO 220 K = TO3

L = TO -92

HEAT SINKSTO.3stvie 95

0.220 style .3_5A

74LS0074LS00 24 7415157 65741502 25 74L5158 59741503 .25 7415161 65741504 .24 7415163 .65741505 .25 7415164 .69741508 .28 7415165 .95741509 .29 7415169 1.75741511 .35 7415173 69741514 .59 7415174 55741520 .25 7415191 .89741521 .29 7415193 79741527 .29 7415194 69741530 .25 7415195 .69741532 .29 7415221 .89741533 .55 7415240 .95741538 35 74L5241 .99741542 49 74L5242 .99741547 75 74L5243 99741551 25 7415244 1 29741573 .39 7415251 .59741574 .35 7415257 59741575 .39 7415258 5974LS76 .39 7415259 2.75741585 .69 74LS260 59741586 39 7415266 55741590 .55 7415273 1.49741592 .55 7415279 .49741593 55 7415280 1 987415107 39 7415283 697415109 39 7415290 897415112 39 7415293 .897415122 45 7415299 1.757415123 .79 7415323 3.507415125 49 741 S365 497415126 .49 74LS367 457415132 .59 7415368 457415133 .59 7415373 1 397415136 .39 7415374 1.39741.5138 .55 7415377 1 397415139 .55 7415390 1.19741.5148 1.35 7415393 1.19741.5151 .55 7415640 2.207415153 .55 7415670 1.497415154 190 741.5682 3.207415156 69 741.5688 2.40

74S0074S00 32 74586 .5074S02 .35 74S112 .5074504 35 745124 2 7574505 35 745138 .8574508 .35 74S157 9574510 .35 745175 9574511 .35 745240 2 2074520 35 745280 1.9574S32 .40 745287 1.9074S74 .50 745288 1.90

74007400 19 7447 .697402 19 7473 .347404 .19 7474 .337405 .25 7475 .457406 29 7476 .357407 29 7486 .357408 .24 7490 .357410 19 7492 .507411 25 7493 357414 .49 74121 .297416 25 74123 .497417 .25 74132 457420 19 74151 .557425 29 74154 1.257430 19 74157 .557432 .29 74164 .857438 .29 74168 1.007442 49 74192 .797445 69 74193 79

CMOS4001 .25 4069 294011 25 4070 354013 38 4071 294015 .39 4081 .294016 39 4093 .494017 69 14411 11.954020 75 4511 .854024 .65 4518 .894027 .45 4520 .794040 .75 4553 5.794042 .69 4584 .754046 .85 74C00 354049 .35 74C04 .354050 .35 74C74 .354051 .79 74C925 5.954066 .39 74C926 7.95

VISIT OUR RETAIL STOREHOURS: M -W -F, 9-5 T-Th., 9-9 Sat. 10-3

PLEASE USE YOUR CUSTOMER NUMBER WHEN ORDERING

TERMS Mieimum o -der $10 For shipping and handling Include52.50 for UPS Grouni end $3 50 for UPS Air Orders over 1 lb andforeign orders may sequire additional shipping charges - pleasecontact our sales deprtmen/ for the amount CA resident. mullinclude Eif o soles las Say Ares and LA residents include 6' Pricyssubject to -hinge Without notice W. are not responsible fortypographical errors We reserve the right to limit quantities and tosubstitute rrenufactizer All merchandise subject to prior sae*

Seith.mher 1984 Circle No. 22 on Free informatbn Care

rs Electronics MarketplaceCLASSIFIED RATES: Per Word. 15 Word Minimum COMMERCIAL: $5.00 PERSONAL: $3 00 EXPAND -AD : $7.50. Ads set in all bold type @ 20% premium. Adsset with background screen @ 25% premium DISPLAY: 1 x 21/4 $605.00. 2' x 21/4". $1.165.00 3' x 21/4 . $1.675.00. GENERAL INFORMATION: Frequency ratesand prepayment discounts available. Payment must accompany order except credit card -Am. Ex.. Diners, MC. VISA (include exp. date) -or accredited ad agencyinsertions. Copy subject to publisher's approval: must be typewritten or printed First word set in caps Advertisers using P.O. Boxes MUST supply permanentaddress and telephone number. Orders not acknowledged. They will appear in next available issue after receipt. Closing date: 1st of the 2nd month preceding coverdate (e.g.. Mar. issue closes Jan. 1). Send order 8 remittance to Classified Advertising. COMPUTERS & ELECTRONICS Magazine. 1 Park Avenue. New York. NY10016 To Charge your ad to a major credit card. call Lois Price at (212) 503-5115.

FOR SALE

GOVERNMENT and industrial surplus receivers. transmitters. snooperscopes. electronic parts. Picture Cata-log 25 cents Meshna. Nahant. Mass. 01908.

RECONDITIONED TEST EQUIPMENT $1 00 for cataiog.WALTER'S TEST EQUIPMENT. 2697 Nickel. San Pablo. CA94806. (415)724-0587.

ELECTRONIC CATALOG. Over 4,500 items Parts. d com-ponents. Everything needed by the hoobyist or techni-cian $2.00 postage & handling (United States Only).refundable with first $15 00 order. T & M Electronics. 472East Main St.. Patchogue. NY 11772. (516) 289-2520.

PRINTED CIRCUIT BOARDS, your artwork. Ouick deliv-ery. Reasonable. Atlas Circuits. Box 892. Lincolnton. NC28092 (704)735-3943.

POLICE CODE UNSCRAMBLERS. lets you hear the codedmessages of Police. Fire and Medical channels plus otherscanner accessories. satisfaction guaranteed DNE IncRt 7. Box 257-A. Hot Springs. AR 71901 (501)623-6027

CABLE TV CONVERTERS & EQUIPMENT. Plans andparts. Build or buy. For more information send $2.00: C

& D ELECTRONICS INC., P.O. Box 21, lenison, MI 49428.

FREE FLYER' IC s. resistors. capacitors. lacks. etc.. plusSSM music synthesizer/audio IC's. power amp modules.analog delay IC's. computer books, and more. Also plansfor analog delay/chorus unit' PGS Electronics. Route 25.Box 304 Terre Haute. IN 47802.

FREE Catalog of special function IC's and quality com-ponents Goldsmith Scientific. Box 318M. Commack. NewYork 11725

RADAR JAMMER!At.

Causes speed radar guns to read out rather: -a per-centage of your true speed. or whatever speed you dial in Activated by your Escort and most other detectors Especially effective against instant -on radar Operates on both X and K bands (not FCC approved) MONEY -BACK GUARANTEE. if not satisfiedWARNING. The device described in this literature is notlegal for use against police radar

Complete literature & plans package, send $14.95 to.

Philips Instrument Design Co. Inc.9513 S W Barbur Blvd. #109 C Portland, OR 97219

VISA and M/C order line (503)62A 6764

1,0

MICROWAVE ANTENNA SYSTEMS

Freq 2 1 to 2 6 GH: 34 db Gain COMPLETE SYSTEMS las IlliClurel11Commercial 40' Rod Style 589 95Parabolic 20' Dish Style 57995

TWO YEAR WARRANTYPARTS AND LABORCALL OR WRITE FOR KITS PARTS INDIVIDUAL COMPONENTS

Ws P.palr All Typos DownConverters & Power Supplies

Phillips -Tech CCElectronicsP.O.1101134772 TH Phoenix. AZ 8506716021967-6972 C00 'S

Special Quantity Pricing Dealers Wanted

FREE! 1984 CATALOGUE. 1001 bargains. Speakers -parts -

tubes -video cassettes --record changers --tape re-corders -kits. EVERYTHING IN ELECTRONICS. Write:

McGEE RADIO & ELECTRONICS, 1901 McGee Street,

Kansas City, MO 64108-1891.

/(,A,- MULTMICIROW AVE-CHANNEL

Complete Antenna Systems from '69"

Full 800 Mhz RangeTune 1.9-2.7 GhzIncludes allITFS Channels

DEA! FRS WANTED

COO 's and Credit CardOrders call TOLL FREE

1-800-247-1151

GALAXYELECTRONICS5644 N. 53rd Ave.Glendale, AZ 853011-602-247-1151

ISILVERSTAR

TELESTOP tt

TV & RADIO TUBES. 59C each Send for free catalog Cor-nell. 4213 University San D.ego CA 92105

- PHONE LISTENING DEVICEaeCnrO t.i.onort cOn +0,141.0A9 y 0 u0 ,,K , ,NO,,,O C00,n/C 0.111.cassette or 'non reco,ft. end pow mon0007. I m VS, I. 00,WIIIIC11 yProtto0.11 pesorrho0 PrIcrodp both whinConvorsonon Stop, won't., panto phone hung up

1995.. 04 discounts available

WIRELESS MIC_

l0 lona MOO, pcnrootto, that, hour. nice rttr tr1:,",C'Vl.013119.1.;;;-.1007r 5:0

SD nicri II.50arita.g.o.L.IrontFlti

us, Clrgcoo

(k,

posoptel On. crootog ot ttrountnetr 0000 SUOMI.otter .Motterwort/hop owns enc..* $2 to 151

12 SATELLITE DISH AND POLAR MOUNT. Total weight125-lbs. For $189.00. For information send $4.95 (Re-fundable u.p.) to: Satellite Operational Systems, P.O. Box2002, Titusville, FL 32781.

CABLE TV products. Jerrold, Hamlin and Oak. send $3.00to ADDITIONAL OUTLET CORP., 111 E. Commercial Blvd..Ft. Lauderdale, FL 33334.

HARD TO FIND lightbulbs thousands types buy. sell Jetco.P.O. Box 8755. Newport Beach. CA 92658.

LOWEST POSSIBLE PRICES ANYWHERE! ComputersHardware -Software -Printers. Audio, Video. Car StereoELECTRIFIED DISCOUNTERS. 996 Orange Ave.. WestHaven. CT 06516 MC/VISA. (203)937-0106.

CABLE TV EQUIPMENT, Notch filters for -Beeping" Channels Information $1.00 Goldcoast, Box 63/6025 CE. Margate, Florida 33063(305)752-9202

FREE CATALOG! UTILITIES, games amateur radio soft-ware for VIC-20 Commodore 64. TI/99/4A. RAK Elec-tronics, Box 1585. Orange Park, FL 32067.

MICROWAVE ANTENNAS. Stormproof, Burnout -resintent, drift -free. $89. Free info. JCR Service. Box 20607Denver. CO 80220

ALARM EQUIPMENT WHOLESALE' Burglar. Holdup. Fire.Medical We can prewire. Easy installation' Fast policenotification service. Nationwide! Catalog $1 00. U S. De-tection, 109 21st Dept. CE South. Birmingham, Alabama35233

Computer/Satellite modulators, CCTM cameras, moni-tors, MATV. Kits. Free video catalog. Phone (402) 987-3771. Dealership available. ATV Research, 13 -CE Broad-way. Dakota City, NE 68731.

CABLE TELEVISION FACTS AND SECRETS. Now you canget the informative publication that CATV companies havebeen unsuccessfully trying to get banned for 15 years.Movie Channel. HBO and Showtime converters. etc. Send$8 75 to: CABFAX. PO. Box 091196. Bexley. Ohio 43209.

111.44=1.-electronics

ORGAN & PIANO KITSALPHA DX 300

fullyDIGITALR S 232Interface

For Free Sound InfoCall 1- 800-233-3865or write WERSI USA

Dept. M3 P.O. Box 5318Lancaster, PA 17601

MICROWAVE ANTENNAS COMPLETE WITH WAR-RANTY from the original manufacturer. Three stylesDaisey, Parobolic. and Yaggi. We also repair all down con-verters and power supplies. S.A.P. Box 2319 Glendale, Ar-izona 85311.(6021973-9117

CABLE T.V.EQUIPMENT. JERROLD. HAMLIN, OAK. alltypes. We also have Jerrold SB-3 in kit form. All parts andinstructions included. Dealer inquiries invited. S.A.P Box2319 Glendale. Arizona 85311 (602)973-9117.

HUNDREDS OF CARDS FOR IBM. Apple. Commodore.listed by function. $7.50. Axcess. 3030E Mountain View.Bath, PA 18014.

SATELLITE TV RECEIVER BREAKTHROUGH' Build yourown system and save' Instruction manuals. schematics,circuit boards' Send stamped envelope XANDI. Box 25647.Dept. 22A. Tempe. AZ 85282.

A SINGER'S DREAM!

REMOVES VOCALS FROM RECORDS,Now You can sing with the world's best bands!

The Thompson Vocal Eliminator can removemost or virtually all of a lead vocal from a standardstereo record and leave the background!

Write or call for a free brochure and demo record.LT Sound, Dept. C E, P.O. Box 338,

Stone Mountain, GA 30086 (404)493-1258

COMPUTER EQUIPMENT/PARTSSAVE 9004 Build Your Own Minicomputer. Free Details. Di-gatek. 2723 West Butler Dr.. Suite 20C, Phoenix, AZ 85021.

48K APPLE COMPATIBLE COMPUTER: US $380.00 andhundreds of programs. Details US $1.00. Reliant, P.O. Box33610. Sheungwan. Hong Kong.

118 Computers & Electronics

FREE 64 PAGE COMPUTER CATALOG crammed full ofthousands of the best buys and lowest prices around! A.P.COMPUTER PRODUCTS, Dept. CC. 214A East Main, Pat-chogue, NY 11772. (516) 698-8636.

WANT A PLEASANT SURPRISE? Call or write for quotes'Atari, Commodore. Timex, T.I . Corona (IBM work -alike),Amdek, Gemini. Apple A IBM accessories. Hayes. More.GET SURPRISED' HARDWARE SOFTWARE ANYWARECO.. 10 Coles Street. Brooklyn. NY 11231. (212) 596-3592

USED COMPUTER terminals. printers. modems. cables.surplus electronic parts Specials: CRT's $20.00. Hard-ware Modems as -is $15.00. Catalog $1.00 Rondure Com-pany. 'The Computer Room" CE. 2522 Butler Street. Dallas.TX 75235. (214) 630-4621

REPLACEMENT RIBBONS for computer printers and wordprocessors. Fantastic saving, Thousands in stock. Quickdelivery. Call/write: 1 (800) 292-6272. National ComputerRibbons, 114 Elbank Ave . Baltimore. MD 21239

COMPUTER SOFTWARE

FREE VIC-20 and COMMODORE 64 USERS GROUPMEMBERSHIP with software purchase. Why pay to be-long to a users group when you don't have to" Benefits.Newsletter, extensive club library, discounts. contests.questions hot-line and more, Free details -(803) 797-1533Lords of Basic. PO. Box 459. Dept 102 Ladson. SC 29456

DISKETTE FORMAT CONVERSIONS/DOWNLOADING.from $5 00 Port -A -Soft, 423 #800 N. Orem. UT 84057 801/226-6704

TS 1000, TI99/4A. VIC-20 Software Turns Programs intoProfits: Catalog: Midwest Software, 9922 Harwich. Crest-wood. MO 63126.

HORSE & DOG HANDICAPPING PROGRAMS FOR MOSTPERSONAL COMPUTERS. Free Catalog: Gambler's EdgeComputing. Dept. B6. 250 Richards Rd.. Suite 254. Kan-sas City. MO 64116. 1-(800) 821-3343. 1-(800) 471-8660.

RENT PUBLIC DOMAIN SOFTWARE. It's not copy-righted. no fees to pay. Copy hundreds of useful business.utility and game programs from our rental libraries ontoyour own computer at home, SASE NATIONAL PUBLICDOMAIN LIBRARY. 1062 Taylor. Vista. CA 92083 (619) 941-0925

DISCOUNT Computer -Software. Wargames. Video cas-settes. FREE catalog. Wizard Entertainment. Box 509.Saugus. CA 91355

FREE T199-4A/TRS80-COCO/TRS80-MCI0/VIC-20/71-MEX program, Send stamps, eZRA EZRA Company, Box5222-CES. San Diego. California 921005

COMMODORE 64 Educational package. Eng, Math, Sci-ence. 104 programs on 8 discs. $39.95. Millsons, Box 180,Kennesaw, GA 30144.

COMMODORE 64 OWNERS. Rent software for less.Hundreds of programs on tape. disk. and cartridge. Nomembership fee. Rental charge can be applied towardpurchase. Copy system 1.0 on disk -$19 95 Will back updisk and cartridges. Call or .write for free catalogue, Cent-sible Software. PO Box 263. Stevensville. MI 49127, (616)465-6632

VIC-20 COMPLETE SERIES OF QUALITY educationalprograms, all under $15.00.For free brochure writeSchool -master Programming Company. Box 194. Po-mona. CA 91769

WE WILL beat any price. SSOD-Maxell-521 95/10 -Dysan-S26 95/10. 1-1800) 245-6000: Tape World. 220Spring St., Butler. PA 16001(412)283-8621 Free catalogue

TI -99/4A Softwares for personal, home entertainment, andbusiness applications. Write for free catalog to. Micro-BixHawaii. Dept. P 98-1409D. Kaahumanu St.. Afea. Hawaii96701

TI -99. VIC-20. COMMODORE 64 OWNERS. Proteus" of-fers quality BASIC CASSETTE software. All programs un-der $8. Free catalog. PROTEUS PROGRAMMING'. POB894 -CA, Bala -Cynwyd, PA 19004.

ENGINEERING SOFTWARE -Free flyer. Graph PrintingProgram, $52.95. Circuit Analysis. $52.95. MSDOS. CP/M,TRSDOS. BYE, Box 3429. Riverside. CA 92519. (714) 781-0252.

FREE SOFTWARE. Earn "BONUS BUCKS" for FREE Soft-ware. Books and Supplies. Catalog $1.00 (refundable withorder) Specify model. Computer Discount Center Inc.,Dept. CE. PO Box 1548. Springfield, VA 22151

COMMODORE 1540/1541 single disk copy -backup progand more HUMBOLDT ELECTRONIC. 2205 Driscoll Drive.Reno. NV 89509

TI -99/4A NEW RELEASE (spelling) learning aid for all ages,(Terminal emulator II. Speach Synthesizer required). Cas-sette $9.95 B.W.G.. 5508-39 Avenue, Kenosha. Wiscon-sin 53142.

FOR SUPER SAVINGS ON DISKS (Verbatim or 3M S/D-$21,D/D-$26). Modems (Hayes 1200-5479, 1200B-$399),Printers. Paper & Cables call (513)861 -SOFT. Will beat anypublished price, Visa/MC/COD.

VIC 20/COMMODORE 64 SOFTWARE FREE CATALOG'Inexpensive, practical programs. Education/Home/Business. Over 50 titles! FARTHEST FRINGE S.A.. 101Highway Blvd., N Pekin, IL 61554.

MAXELL MD -1 DISKETTES $25.00/10 plus $1 00 S&HVISA/MC. Cottage Resources. Suite 243. 1032 StevensonDrive. Springfield IL 62703

TI -99/4A OWNERS. Get your free catalog of new. exciting.low cost software DE. Box 690. Hicksville. NY 11801

COMPUTER HARDWARECOMPLETE COMPUTER schematic. Z80 or 8080 system24"x36" sheet notes $10.50 Schematic. 1443S 680 E.Orem. UT 84058

*SUPER SAVERS* Apple Compatible Floppy $165, 1/2

ht. $175, Hard Disk 10mb $1395, Monitor 12" Amber or

Green $115. Internal 10mb Hard Disk for IBM $1095,

Floppy 1A551.2 $174 Oztech. (800) 222-6697, Califor-

nia (408) 980.9987.

COMPUTER GRAPHICSAVL computer graphics A programming systems. Slide.Motion. Overhead. Video. & Audio equipment & supplies.Rentals & Staging Custom Graphics. Slides A Presenta-tions. NEW ORIENT MEDIA -IL. 1-1800) 223-9473. 1-)312)428-6000

TIMEX/SINCLAIRAERCO will continue to provide high performance disk.printer. and other interfaces for ALL MODELS of Timex/Sinclair computers. Box 18093. Austin. TX78760. (512) 331-0719

ZX81 TEXT PROCESSOR- 16-64K RAM. 1100-7700words. Write. read. edit. print. save. clear text Full or win-dow -screen editing $12.50 tape/instructions. Check /m o.:A Rodriguez 1605 Pennsylvania Ave 204. Miami Beach.FL 33139

Timex 2068 programs. Wall street: Biorhythms: Disas-semblers. Star Trek and many more. $10 each. SAE plus$1 for comprehensive list. C Dos-Santas. PO. Box 9521.Fountain Valley. CA 92728.

QUICKLOAD CARTRIDGE plugs in. Saves/loads TS1000/1500 programs 15 TIMES FASTER. Stores MEGABYTE oncassette. $33 95 Catalog SASE. ROMPAK. 8206 Black-burn Ave . LA. CA 90048.

C.B. EQUIPMENTCB MODIFICATIONS. conversions. books, plans. kits. repairs. Catalog $2 CBCI, Box 31500PE. Phoenix. AZ 85046(602)996-8700

CABLE TV.CHANNEL 3-60db notch filter. 66 5MHz $32 Crosley.Dept 607 Box 840. Champlain. NY 12919

CABLE TV SECRETS, the Informative Publication the

Cable companies Tried to Ban. HBO, Movie Channel,

Showtime converters, etc. -$8.95. CABLE FACTS, Box

711 -PE, Pataskala. Ohio 43062.

CABLE TV CONVERTERS and modulators. Commer-

cial types. BEST PRICES. Catalog $2.00. Profes-sional Video Inc., 4670 Hollywood Blvd., Hollywood.CA 90027.

PLANS AND KITSMICROPROCESSOR CONTROLLED. Six voice polyphonic synthesizer plans. $15 00. Syntron 10751/2 Mill RdHelena. Mt 59601

Communicate for miles with other computers with nocense radio link Study package with full details. sources$8 00 refundable.Broadcast Technical Services. 11 Walnut St . Marshfield. MA 02050

PROJECTION TV CONVERT your TV to protect 7 footpicture Results comparable to $2.500 protectors .. To-tal Cost less than $30.00 ... PLANS AND 8" LENS $19.95. Illustrated information FREE. Macrocoma-CA Wash-ington Crossing. Pennsylvania 18977. Creditcard orders 24Hours. (2151736.3979

WANTEDGOLD. electronic. circuit board scrap. silver. platinum.tantalum, mercury. Ores. metals assayed. Samples eval-uated Wholesale Terminal, toll free 1-800 -932-1010. (617)326-3442 in Mass.

GOVERNMENT SURPLUSIS IT TRUE YOU CAN BUY JEEPS FOR $44 THROUGH THEU.S. GOVERNMENT, Get the facts today, Call (312) 742-1142 Ext. 4649

TUBESTUBES Oldies . Latest Supplies. components schematics Catalog Free (stamp appreciated) Steinmetz 7519PE Maplewood. Hammond. Ind 46324

HUGE NVENTORY' Thousands of types Wholesaleprices. FREE CATALOG, ETU/ Electronics. DEPT 290.Plattsburgh. NY 12901

TUBES RECEIVING. Industrial and Semiconductors Fac-tory Boxed Free price sneet including TV, radio and audioparts list TRANSLETERONIC. INC . 136539th St . Brook-lyn. NY 11218 Telephone (2121633-2800 Toll free 18001221-5802 Ask for Abe.

TV 6 RADIO TUBES. 59' each Send for FREE CATALOGCornell 4213 University. San Diego, CA 92105

7.000.000 TUBES. Worlds largest inventory Free cata-log. UNITY ELECTRONICS. Dept CE. PO. Box 213 Elizaheth. NJ 07206.

PERSONALSMAKE FRIENDS WORLDWIDE through international co.respondence. illustrated brochure free. Hermes-Verlag.Box liossna. D-1000 Berlin 11. W Germany

FREE. WORLD'S LARGEST PARTNER PHOTO CATALOGfor friendship and marriage Personalized introducThoosINTERCONTACT. Box 12. Toronto, Canada M4A 2M8

ORIENTAL SINGLES seeking cultural exchange, friend-ship, sharing, marriage. WRITE CHERRY BLOSSOMS.Box 1021P Honokaa, Hawaii 96727

CORRESPONDENCE TO ASIA FOR LASTING RELA-TIONSHIP Free information AAWS-CE. Box 2777. OrcuttCA 934550777

COMPBTERIST T-SHIRT Best self -advertisement ever"Next to my sex drive. I like my disk drive best also avail-able. -I m user friendly, lust turn me on - (c/ 1984 Syn TaxInc Royal Blue with White lettering: Hanes 50/50 for min-imum snrinkage $8 95 plus $1 shipping/handling. Spec-ify s.m.I.XL Check. Money Order. VISA/MC (Includeexpiration date) to Syntax Inc . Dept C F.. Box 2133. PhiloPA 19103

INSTRUCTION

UNIVERSITY DEGREES BY SPECIAL EVALUATION of

existing credits and lob Experience. Fast, inexpen-sive. Call (614) 863-1791. Or write: EVALUATION, Box

13151-A9, Columbus, Ohio 43213.

REPAIR ELECTRONIC ORGANS- Revised home studycourse covers all current makes and models. Free book-let. Niles Bryant School. PO Box 20153. Sacramento. CA95820

LEARN WHILE ASLEEP, HYPNOTIZE' Astonishing de-tails. s:range catalog tree' Autosuggestion, Box 24 PD.Olympia. Washington 98507

MEDICAL ELECTRONICS TECHNOLOGY, home studyTroubleshoot medical instruments. WTI, P.0 Box 3124Fresno. CA 93650.3124

HANDLE YOUR OWN LEGAL AFFAIRS -Be a Paralegal.Accredited Attorney Instruction. Home Study FREE CATALOG Southern Career Institute. Drawer 94CE-2158. BocaRaton. FL 33427 (3051368-2522

EARN SE100-i-WEEK, Get your 'F C C Commercial Rath-otelephone License- at home 'Free- details. COMMAND.

'-1 Box 2271 San

Be an ELECTRONICSTECHNICIAN! Getyour 2 -YearASSOCIATE

DEGREETra n at homein spare time. `.i Mow tram e inting opportunities m the fast -gm* ing spare -age Indus -Ines., automation. aerniipare fable -TV. Ibrolle Dowry ElectronicCircuitry. fomputers. Telemetry and moth. meth more 'so previous',Terror. neceman So met In quit your gob Your atomise. Degreegive. uou everything you need to qualify for an Electronics TechnicianPompon Instructoni are as clone as your telephone. Ire our 24-liourhome -study lent hoe --re pay the hall. Send for free farts 'so obligation.

bo salesman will rail Mail coupon today!

'at'Centel tor Degree Studies, Deol. P0084 1ICS Electronics Center. Scenron PA 18 515

Ruth free facts Plinths. I ran train to he an Electronics Terhntrian andget n 2 -ter Amami. Degree al home in spare time.NAME AGE

ACIORIS3

CITY/STATE/ZIP.1

BUSNESS OPPORTUNITIESERASE DEBTS with little-known law -create wealth', Details FREE -Wealth Kit. Nn FE9. Billings. NY 12518

September1984 119

MECHANICALLY INCLINED individuals ownerdesiring PATENT AND DEVEL OP your invention FREE PATENTINFORMATION Richard L Miller PE 3612-E Wool-worth Building. New York NY 1000712121267-5252

-

ship of Small Electronics Manufacturing Business --without investment Write BUSINESSES. 92-K9 Brighton 11thBrooklyn, New York 11235

ONE MAN CRT FACTORY TV S. Business machines.Monitors Scopes. VDTs $3 00 rebuilding nets 5100-5500each tube Higher profits overseas New/used FACTORY.1909 Louise. Crystal Lake, IL 60014 (815) 459-0666

BORROW $300-$30 000 INTEREST FREE' Keep indefi-nitely' Free Details Write American. 1601 Main, Plain-field, Indiana 46168

BUMPER STICKER PRINTING DEVICE Cheap. simpleportable Free details Bumper. POB 22791 (PE), Tampa.FL 33622

FREE CATALOGS Repair air conditioning. refrigerationTools. supplies, full instructions. Doolco. 2016 Canton,Dallas. Texas 75201

MAIL ORDER OPPORTUNITY' Start prof table homebusiness without experience or capital. Information freeMail Order Associates. Inc Dept 38 Montvale. NJ 07645

REVEALING. 40 page. info pack. on how to start your ownCOMPUTER hardware/software MAIL ORDER/RETAILbusiness Send 51G to JPI PO Box 7033. Huntington Beach.CA 926t5

MULTI -CHANNEL microwave antennas Highest qualitylow prices dealers welcome D T compact $38 00. PT .1$48 00. SR 1 $65 00. D T Grid $69 00. PTS-33 $75 00 Aliunits complete' Daisy Tenna. Box 42010. Phoenix 850801(800)874-9033

MAKE $THOUSANDSS with your computer Valuable guidefor setting up and operating a computer labeling serviceRush $25 00 to H C Enterprises. PO Box 112, Falls. PA18615

HOW TO START AND OPERATE your own profitable busi-ness at home 100 guaranteed. Send for free brochureto Billy King. Box 1378 Borger. Texas 79008

'HOW TO ACHIEVE FINANCIAL INDEPENDENCE withyour microcomputer Report $1 00 VIKING. Box 730-CE1Coleman. Alberta. Canada. TOK OMO U.S INOUIRIES

PROJECTION TV ... MAKE 555's assembling Projectors...Easy . Results comparable to $2.500 projectors. Yourtotal cost less than $20.00. PLANS. 8' LENS 6 Dealersinformation $17.50 ... Illustrated information FREE ..

Macrocoma-CAX. Washington Crossing, Pennsylvania18977. Creditcard orders 24 Hours (215) 736-2880

FOR INVENTORSINVENTIONS. IDEAS. NEW PRODUCTS WANTED, Indus-try presentation/national exposition Cali free 1.800-528.6050- Arizona 1-800-352-0458 X831

INVENTORS' IDEAS HAVE VALUE'

Ever think of an idea forget it and see it later on themarket/ Many people don t forget act quickly andare rewarded by American Industry Write downyour idea. We otter free disclosure registration and,nitial consultation regarding your idea s potentialvalue Call or write without delay for your free informatron package

AMERICAN INVENTORS CORPORATION82 Broad St Dept CEWestfield. MA 01086

413-568-3753

A Fee Rased Marketing CompanyOffices Coast to Coast

REAL ESTATE

500 OFFICES 45 STATES' 30.000 listing on computer16.000 under $50.000' Free printouts and regional cata-logs' UNITED FARM AGENCY. 612 -EP West 47th. KansasCity. MO 64112 Ph 1.800-821.2599 in MO 1-800-8925785

INSURANCE

SAFEWARE If your computer is important to you. insureit' SAFEWARE provides full replacement of hardware.media and purchased software. As little as $35 00 a yearfor comprehensive coverage including fire. theft, powersurges. earthquake. water damage, auto accident Call 8to 8 Mon through Sat SAFEWARE, The Insurance Agency,Inc . 2929 North High Street, Columbus. OH 43202. (8001848-3469 (nat). (614) 262-0559. (OH)

EMPLOYMENT OPPORTUNITIES

ELECTRONICS/AVIONICS EMPLOYMENT OPPORTU-NITIES Details FREE Aviation Employment InformationService Box 240E Northport. New York 11768

BOOKS & MAGAZINES

41

SATELLITE TV VIEWERS

Send S1 for sample copy.

"P.O. Box .1082, Fortuna, CA 95540-1100-330-117 (U.S.) 600-536.11787 (WIC)

707-7254476 (all ethers)

INTERESTED IN HOME SATELLITE T.V.?Lear!, how it works what serviCeS are available nowto buy d system And more through the new booklet

Tuning In To Satellite T.V.,,1 .J.,t And `:end 4 with your nano- and art

{wr-t Ste R uandhno to

Tuning In To Satellite T.V.PO Box 2228 Dept. J.Halley, Idaho 83333

MISCELLANEOUS

BASIC DATE SUBROUTINE --Input mmddyy, outputmonth dd. 19yy f- weekday month dd. 19yy more Forcomplete. compliable. source code. documented, sendcheck $19 95 Ice System Inc 345 Queens St a980Honolulu. Hawaii 96813

COMPUTER LOVERS GIFT CATALOG Chocolate cornouter's, diskette ties, computer clocks. jewelry and wal-lets Write SweetWare. 516 Shelburne Road. SouthBurlington. VT 05401 (802)862-6939

LOOKING FOR SOMEONE SPECIAI IN YOUR LIFE/Compatible Companions International, Box 2253. Can-oga Park. CA 91306

CLASSIFIED ADVERTISING ORDER FORM

1 2 3 4 5

6 7 8 9 10

11 12 13 14 15 (MINIMUM)

16 17 18 19 20

21 22 23 24 25

26 27 28 29 30

;keine reef to heading on fird one 't Pm section for act placement information

REGULAR: $5.00 EXPAND -ADP': $7 50 (per word)* OF WORDS a OF INSERTIONS _

PAYMENT ENCLOSED

CHARGE You will be billed monthly Amencan Express Diners Visa MasterCharge Interbank a

Account a

SIGNATURE

PRINT NAME

ADDRESS .

CITY STATE - /IP

Exp Date

CE -884

FREE - -MAILORDECATALOGTuners, amplifiers, effects,keyboards, studio equipment,drum computers, books,easy to assemble kits & more ..

name

address

city state zip

RUA Electronics, Inc.Dept 1-P 1020 W Wilshire BlvdOklahoma City, OK 73116800- 654. 8657 9AM 5PM CST M -F

CIRCLE NO t4 ON F EE INFORMATION CARD

DRIVE DIAGNOSTIC TEST MENU0 - Orme Seieci H o Head SelectC = Clamp Center $ = Speed

= Radial P = Position ErrorA = A4wfuio I Irides Time111/ Wrote Data V = Vaulty Oats

X Esol to DOS

FLOPPY DISKDRIVE DIAGNOSTIC

Do it yourself and save time and money. Nospecial training needed.

All tests made WITHOUT REMOVING DRIVES.Additional equipment not needed. Our kit alsoincludes users guide that shows how to do thedrive adjustments.

OUR DRIVE DIAGNOSTIC WILL HELP YOUPREVENT COSTLY DATA ERRORS.

APPLE II DRIVE DIAGNOSTIC $119KAYPRO DRIVE DIAGNOSTIC $119

Sheepshead Software"P.O. Box 486

Boonville. CA 95415(707) 463-1833

Phone orders Mon -Sat .9 a.m. to 9 pm..Pacific Coast TimeMASTERNISA Card or COO add STCalif add IP. UPS Slue Label add SS

CIRCLE NO 115 ON FREE INFORMATION CARD

SALESPOWERComputers & Electronics notonly sells itself at a nice profit, ithelps sell the hardware and soft-ware in your store too. Becauseit goes home with customers andcontinues to influence buyingdecisions long after you're closedfor the day. Let's talk now.CALL COLLECT:(212) 725-7679Or write:31 Ziff -Davis Publishing

One Nark AvenueNew York, NY 10016

Minimum order. 10 copies. We pay all shipping costs.

120 Computers & Elm:trades

Computer MartRATE: Ads are " by 3' . 1 insertion: $935.00. 6 nsertions: $900.00 ea. 12 insertions. $865.00 ea. Closing

date: 1st of the 2nd mo. preceding cover date. Send order and remittance to Computer Mart. Computers & Electronics,1 Park Ave., N.Y., N.Y. 10016. Direct inquines to Lois Pnce (212) 503-5115. For Customer Service (212) 503-4506.

COMMODORE 64 INTERFACINGBLUE BOOK

Written by a college professor in a friendly andinformative style. this book is a gold mine ofPractical information on how to build a varietyof useful interfaces for your computer Over 30protects including cassette interface. print. -interface. expansion bus. light pen. RS -2interface. more user ports. thermomeispeech synthesizer and two other voiceleCtS. A'D and D/A converters 5 felon,interfaces including a sophisticated v,Srolect. motor controllers. AC powerlogic analyzer. capacitance meter. surfanalyzer, home security system and m.,.more S16 95 postpaid. Foreign orders addfor AIR MAIL shipping

VIC 20 INTERFACING BLUE BOOK

20 Similar to the 64 book above See wiyOur VIC can do with a lime interimSt4 95 postpaid microsignal

Dept. B. P.O. BOX 22MILLWOOD. NY 10546

MarinlaC)MUMS,

800-231-3880

Can AmorIcat)EtICTIKreiel

800-531-7466

Stadia Shack TRS.40's

People you Trust to give you the very best'

gee

r, 111V-441WS

LowestPrice

ReliableService

OualityProducts

22511 Katy Fwy Katy (Houston) Texas 77450(7131 392-0747 Telex 774132

55CIRCLE NO 98 ON FREE INFORMATION CARL

TRS-80COM PUTER

DISCOUNTS Factory Direct Best Prices Anywhere No Out -of -State Taxes 1000/o Radio Shack Warranty Free Price List Authorized TRS-80

SCOTT TASSOASSOCIATES

175 North Delsea DriveVineland, N.J. 08360

800-257-0426NJ 609.691-7100

IRCLE NO 100 FREE INFORMA ION CARD

September1984

DISCOUNTCOMPUTEREQUIPMENT

LOWEST PRICES on Pr.nters,Usk Drives, Software andO'her Computer Equip. -rent!EPSON Star Mieivnics OkidataTendon, TEAC & Many Others.C3ii roll -free for a FREE catalog:

800-331-38%In Oklahoma Call 91 8 825 1844

gm,/PM ,

'1/4.\-

4_, 911 82 5 -4844 &KAU

'AMERICAN BUSiNESSg COMPUTERS

SAVE ON

DISKETTES

$1807:-;c' $235"Jty 20 5 :tv 10DSDD

S6Tal 52 41 ea Me' DSDO 96TFI1 S3.25 val on las with TyveC sleeves reinforced hobs en

,ste3DISKETTES FOR MACINTOSH 8 NR -150

AT TERRIFIC SAVINGS'3ve Memorex nil ea

Set sw Mg al le tla Iwo ler saw part rasedShaping: VW or 3,1" DISKETTES --ADC $300 per 100'ewer teSkeeed Payment VISA and Mastercard nrosv,..'

--+D °Mars ores, add $3 00 handing charge revs.. ,oents pease add Ilea wart tax

WE WI.L SEAT ANY NATIONALLY ADVERTISED P8111

ON THE SAME PRODUCTS AND QUANTITIES,

Nationwide: 1-800-1121-8827Illinois: 1-312-944-2788Meyer SAM SPM Central Tim.Minimum Order: $35.00

DISK WORLD!, Inc.Sure 480630 Eest Huron Street Chicago, linos 6061.

PROMPT DEUVERY!!!ICs SAME DAY SHIPPING USUALLY,

DYNAMIC RAM256K 150 ns $48 9964K 200 ns 5 7764K 150 ns 5.3764K 120 ns 7 5016K 200 ns 1 21

EPROM27128 250 ns $26.402764 200 its 10.652732 450 its 5 402716 450 ns 3602532 450 ns 4.80

STATIC RAM5565P-12 120 its $43.006264LP-15 150 ns 45.006116P-3 150 ns 656

Factory New, Prime PartsM CRC)PPnCEqSORS UNLIMITED

(918) 267-4961

1,0,1 C .."1 in, /NKr COL C ,ucnounrinu ra on

-- ertat ANALOG I/O BOARDFor Commodore 84. TRW Color. APPle, Timex. 8most any oomputtor with s memory port 8 channelsND 8 8 channels D/A 1.6 y6 ND convert time9 bit re* Easy to program. Box 8 cable available

$220.Software for Commodore 64 & Board

SCOPE-.. A.- .1 Dual trace.

258 samplea taken

4

.,-- - 14iy t rates.from 3 to

72000 Hz. Trigger 8cursor. Disk& printer

n utilities. Averaging.Usable subroutines

" "" F.F.T.frati! 12e re.

'.117>IAttruer

0Hz to 5,

sample frets Map 8phase domain 1 sectNeeds CFIA card

Scope 8 FFT on disk w/manual $85.Similar software for TIMEX on EPROM $85.Pi.ria con or writ, for FREE CATALOG.

(omputer (ontmuum301 Sixteenth AvenueSan Francisco CA 94118 14151 7526294

NEW!SURGE -STOP

Give any circuit 4500 AMPS ofsurge protection by just pluggingit in! $9.95

Surge Suppressor,With EMI/ RFI filtering, 6 plugswitched -15 Amp circuit breaker

$29.95Build Your Own68000 System

with 128KB, 3 -RS232 ports fo,about $250

FREE CATALOGDigatek

Corporation2723 W. Butler Dr., Suite 7

Phoenix, AZ 85021602-995-8371

CIRCLE NO 99 ON FREE INFORMATION CARD

Ifs Simple.CALL AND SAVE MONEY

CIRCLE NO 1 FREE INFORMAT N A

MULTI -CHANNEL currentcarrier transceiver 2 -WAYCOMMUNICATION with anyBSR type device Switch selectable for 8 channels transmit& 3 channels receive OR 3 channelstransmit & 8 channels receive + 1 channelfor on off cmd. Switch selectable for any of the 16 BSR'house codes A thru P To transmit a BSR signal, take theassigned TTL input port high momentarily Upon receiving a BSR 'on' signal, the TTLoutput port goes high and stays high untilreset by BSR 'off signal. An interrupt driven Z-8 micro. completewith power supply (requires 24 vac ct(i 200 ma) on a 4 5" card with 44 pinconnector. 5187.00 Optional RS -232 interface capable of send-ing and receiving all 256 channels, $49.00.

HYDROS CORPORATION HY)/LIS dept C(214)350.8766

6218 Cedar Springs Rd Dallas, Texas 75235

CIRCLE NO 1-03 ON FREE INFORMATION CARD

CONVERT YOUR TVTO A HIGH QUALITY MONITOR

USE WITH COMPUTERS, VCR's I CAMERAS

Kit permits Dual Mode operation on B&W or Color sets Hi -resolution Up to 80Characters per fine Wide bandwidth DireclVideo Sate Easy installation

3 4"ACVM

DVM- I Hot Chasis kit with Audio available

Box 411. Los Angeles. CA 90028(213)466-5533

CIRCLE N-105 ON FREE INFORMATION CARD

PUBLIC DOMAINSOFTWARE

Lots of it available m these formats

- Single sided formatsAct,. !SUMPCrornemco CDOS (SSCID)CrOmemco COOS ISSSD1Cromemco

w Inn Term CPASDEC VT180 IDDIHeath v. Magnolia (OD/IBM PC ICP M 86 SSDD)Kaypro IILOBO MAX 80 IDDIMS,DOS PC DOS (Sri 11

1/WDOS PC DOS IVer 21Morrow M02NEC PC 8001AOsborne 1 1001Osborne 1 (SDISuperbrain 140 06 551Superbram 1351Ti Professional (013)IRS 80 I (Chnikron CP MIIRS 80 Mod 10 (MIA CP M,Xerox 820 (SO)Kern, 820 11(001Zen. 2 90 (48 fin SS

Over 200 disks. most formats S12 per diskSend 52 for PD catalog Sample disk 58

Sheepshead Software"P.O. Box 486

Boonville. CA 95415

-Double sided format.Act,. 105001Crornemco COOS (0500/Cromernco COOS (05501Croniemco

w Intl Term CAMDalarue IDSDDIEPSON 08 10Hewlett Packard HP 125IBM PC ICP M-86 DSLIDI184S 5000Kaypro 4 10MAGIC ComputerMSDOS PC, DOS (ye'MS DOS PC DOS (Ver .

Morrow MD)NEC PC 8801AOlrona AttacheSanyoSuperbrarn 1001TeleVideoToshiba TI00Zeno. / 100 t1111

Now we can make any computersing as well as talk, For only 52/9.

As featured in Ciarcia s

Circuit Cellar

BYTE MagazineSeptember.

October 1982

Microvox.

duce quaI".i may be eat4S -232C 5P' 6502 M,c,. ;

SC -01A ononer,P 64 crystal controlled roil. 3000 cturacler buffer RS -232C and parallel pr- On board power suDInv MUSIC and sound Oren!, !;

MW11Microvol Assembled 8 Testedmvn2Mtcrovoz complete kit

t"0

To Order

In N

MICROMINT Ikn

5299 005219 00

CIR L e 104 ON REE INF RMATION CA

SAVE MORETHAN EVER ON

3M Scotch®DISKETTES

LIFETIME WARRANTY!

$ 1 " 5

r144

14C DSDD(745)._.

20 Oty 20$23551/4' -96TP117461 82.60 ea5'4'0500 --96TPI1747) 63.25 ea8' SSSO (7401 $2.05 ea

SSDD (741) 92.50 ea8' DSDD (7431 93.10 eaShipping: 51/4- DISKETTES -A00 S3 00 per 100 of tractioninerect DISKETTES -Add 54 00 per 100 or tractionthereof OTHER ITEMS Shipping charges as shown rnaddition to diskette shipping charges Payment: VISA orMasterCard COD orders only. add 93 00 Tares: Illinoiscustomers please add 8%

Hours: 9 AM5 PM Control TimeFee Nut service call

Nationwide: 1-800-621-6827In Illinois: 312-944-2788

DISK WORLD!Suite 4806 30 East Huron Street Chicago. Illinois 600''

Authorized DistributorInformation Processing Products all

Thanks to YOU . . . . We're Growingwith YOU and your Computer . . .

LEO ELECTRONICS, INC- P.O. Bak 11307

Torrance, CA. 90510 1307Tel 213/2126133 800,421,9566TL x. 291 9R5 LEO UR

We Offer PRICE QUALITYPERSONAL SERVICE

64K UPGRADE9 Bank (IBM PC) S43.65 1150ns)

541.85 1200ns)4164 (15Ons) S4.85 ea.

(200ns) S4.65 ea.8 Bank (other PC) 538.80 (150ns)

537.20 1200ns)4164 (150ns) S4.85

(200ns) 54.65 ea

256K Mother -Saver- Upgrade8 - 256K - 115Onsl S400.006116P-3 54.40 2732 - 53.952716 -- S3.20 2764 - S7.00TMS- 2716 - S4.95 27128 - S24.00

We accept check, Visa. Mastercard or Purchase Ordersfrom qualif red firms and institutions. U.S.Funds only.Call for C.O.D. California residents add 6V0 tar.Shipping is UPS. Add S2 00 for ground and 55.00 forair All maim manufacturers All parts 100'.. guaranteed.PrIcing subtect to change without notice,

TS1000 ZXEI13 -Color Keyboard

Symbols withConversionInstructions

lactic TS1000-2X8 1 keyboard symbols inHack, Red and Blue. Opaque background.Will fit all standard -size keys. Adhesivebacking for easy application.

Simple illustrated instructions will show youhow to convert a cheap (about 5201 surpluskeyboard to a full-size TS1000/Z)(81 console.

...as easy as stringing wire on a fence." Do's and Don'ts for selecting a surplus key-

: oard. Bonus for the "pro" - Schematic Diagram of

Computer.

MULE ElectronicsDept. 310444 Lincoln Blvd.Venice, California 90291*Add 51.50 P&H . California residents add 6.5%tax. Money -back guarantee, of course.

$12 *

DRIVE CONTROL UNIT

Turns off8 inch Driveswhen not being accessedSave Drive, Save Media, Quiet Operation. Easily installed. Thousands are inuse. For Shugart 800/850, Siemens100/200, CDC Qume DT8, Remex 4000Kit $29.95 Assembled and Tested $49.95

Call or send for literature packageVISA, NlASTERCARD. COD Accepted

cop-rRoruics 716.377-0:1692990 Atlantic Ave.Penfield, NY 14526

ELECTRONICCOMPONENTS

MANUFACTURERS OF QUALITYELECTRONIC COMPONENTS

OVER I 5.0 0 0 DIFFERENT /1Etnr, IN STOCK.

MOUSER ELECTRONICS11433 WOODSIDE AVE SANTEE. CA 92071PHONE 1610 449.2222 TWO 910 -331-1175

CIRCLE NO 106 ON FREE INFORMATION CARD122

CIRCLE NO 107 ON FREE INFORMATION CComputers & Electronics

Now available For thecomputer experimenter!

COMPUTER CONNOISSEUR'S CIEUGH COPTU1NOW SE IN CONTROL WITH YOUR COMPUTER - THE ONLY PUBLICOF ITS KIND WRITTEN F00 THE USER DISCOVER THE SECRETS LEARN THE VERSATILITY Of MODERN COMPUTER COMMAND CON,CONCEPTS EXPERIMENT WITH COMPUTER AND TELEPHONE SYSTEM'.INTERFACE THEM LEARN HOW THEY WORK, WHAT THEY DO Nr$HOW TO GET THEM TO WORK FOR YOU! A COMPLETE TELEPHONEENGINEERING COURSE IS INCLUDED IN MONTHLY CHAPTERS. BRINGING YOU THROUGH STEP. CRO SSSSS ESS. 111.111Lf AND ATOMICSWITCHING SYSTEMS. EXCLUSIVE COVERAGE IN 111010GICAL COMP,INS SYSTEMS TOO$ COMPUTERS AND TELEPHONES ARE THE Put urnTHIS PUSLICTION IS AN ASSOLUTE MUST FOR EVERYONE III ERESr r

tike one you've allbeen Waitiol7

NOW AvAiiOnt

UMPUSLISIIEDMATERIAL

VAT

COMICS

DIRECTORYLISTINGMET.WORKS

AUGESSCODES

ill HadPUBLISHED MON1,

ONE YEAR SUSECRIPTION $14.00ItAMPLE COPT 12.001

SIIBURIP114111 PROBRAIIS 420 DO

COMPUTEL-the complete SOURCE for every,You can now do the things you ve only heard atx,right in the privacy of your own home. Indispensahurelerence to phreaks and hackers Learn how to getall kinds of computer programs FREE. Get the insidestory of big businessSystbms-their quirks and flaws-and remain up to date with vital occurrences withinthe computer industry Computel is a publication de-signed for everyone who has an intense curiosity ofcomputer systems. containing a wealth of hard to lindinformation, codes. and numbers. Published monthly

= (lompets1 Poblishiag Society6354 VAN NUYS BL.. *161-A / VAN NUYS. CA91401

CIRCLE NO 108 ON FREE INFORMATION CARD

TOTALCONTROL

For theTimex -Sinclair

Computer

$ tr

IrrrI I L Ind l i landar

in Illorr, AM Non Vollral RAM

Boat A Tool. $174 ASBone Rowe 54005

TERMS ChocK of Mono, Ord.,Colo, Ram Add IS%

SHIPPING Inerdo U S $500Out1000 U S S10 00

whilk

..IRCLE NO 110 ON FREE INFORMATION CARD

1/06aX. SC -01ASPEECH SYNTHESIZER

$42 Each($32 inhundreds)

17oliesx'

Order in Ones or ThousandsThe SC -01A Speech Synthesizer is a completely

sell -contained solid stale device This single chq,

phonetically synthesizes continuous speech ofunlimited vocabulary

Computer interlaces and text to -speech algorithmsalso available for product developmentMicromint is the largest U S distributor of theSC -01A Call us for a price quote

Call 1-800-645-3479. In N Y 1-516-374-6193MICROMINT INC561 Wald* AvenueCedarhurst NY 11516=

Ada 02 00 lotsh,pp,ng & vending

CD 3624PS 3024

- Genuine OakVeneer '89" Each

Completely Finished - Ready for UseExcellent for Student, Home or Office

Send name and address with check or moneyorder for $89 95 per unit Specify model no Add$15 00 for castors Include $10 95 for promptshipping Mail to C.F.M.P

O. Box 520652 Salt Lake City, LT 84152MONEY BACK GUARANTEEisiOn 01

eSS Computer Furniture Manufacturers

ALLOPHONE SY51H1515-UNLIMITED VOCABULARY

TOROIDAL POWER TRANSFORMERSSmall size Low noise Easy mounting

Made In U S A

Custom sizes ISVA-3.00004 el 50 30 HI40 'tandem transformers with117V &OH, primaries in stockfor 20VA 400A. 70VA. 100VA.150VA 3404A. 60004Coal or write for date sheets

SeconderiesSlze VoltsTAmps20VA 2485V 118AOD 2.4" 2412V/ 83/1E4 1.2" 2415V; 67AWt lb. 2418V/ 56A

224V/ 42AMultivoltage 'T

100VA 24V 15AOD 3 7" 20150/5 BAH 14" 2a121//4 15AW1 2.2 lb. 2415V/3 3A

2a 18V/2 BAMultivoltage*.

800VA 220V'2 73AOD 5.5" 2424%1,12 5AH 2.4" 2430V/10 OAWt. 62 lb. 2433V19 1A

2o38V/7 9A

Price Each1 2-4 5.24

124 30 $20 40 117 9024 30 20 40 17 9024 30 20 40 17 9024 30 20 40 17 9024 30 20 40 17 9029 30 25 20 22 40

$2910 $2480 $221030 00 25 70 23 0030 00 25 70 23 0030 00 25 70 23 0030 00 25 70 23 0037 00 32 50 29 50

$5900 $5000 $445059 90 50 90 45 4059 90 50 90 45 4059 90 50 90 45 4059 90 50 90 45 40

Ouol Anon*. may so. 1 Prana HE M Tor ST and ITV or ST nd rpura$1. DCTerms VISA MAST E RCRD COD or mon, ore r -UPS ono,.

301-464-2100 TOROULCsORPOHIli

RRdATSION 0oRM .F.M.,,A711YLANJW

BUILD YOUR OWN COMPUTER!!

sew) BASED MULTI BUS COMPATIBLE KIT

4 BOARD SET INCLUDES:' WO'

Sr HF %IA'S $,7 4 .L.s.$,I .

'RI COMPUTER ISIT I ELATOCIANDS ONLY,004 COMPUTER Kir I uNTESTEDBOIRE6 POPULATED!'002 COMPUTER or I DOCUMENTATION ONLY1003 Pk FOR RAN BOARDIOOS CP si FOR KIT I INCLUDES MOS

WE CARED A COMPLETE LINEOF ELECTRONIC CCAlPcnEN,

SEND FOR A FREE CATALOG I.'

4

NICOAN ELECTRONICSloot) CANOGA AYE URI1 8cmAtSw011114 CALIF Mr

818 341 8833

IRCLE NO 1090N FREE IN

fin 991899 991 35 00S 16 99$ 150 00

*MICROCOMPUTER*,

BUSINESSSOFTWARE

MEDICAL MGMT...DENTAL MGMT...INSURANCE AGENTLEGAL BILLINGPROPERTY MGMT..AND MUCH MORE !

UNIVAIR INTERNATIONAL9024 St. Charles Rock Road

ST. LOUIS, MISSOURI 63114

(314) 426-10991

L INC.Lt NU i i I UPI P TICC 11,11,..)PlIVIA I ILAN L...AIYU

GREAT DISKETTESSuper low prices

SYNCOMsw priced high cluakty disketternth a LIFETIME WARRANTY Pacsed

- .nags or 10 wall Tyvek envelopes moms and reinforced nubs r. 'hp ors? toys ye ye seen

$139,, lea 51/4"SSIDD $ 8551/4" DSDD ea. on, 20

N OREM VALUES:OISKETTE 70 r' diskettes in dust ree safety . ea TISKCADDIES holds 10 5,k' diskettes $1.16 ea 20

11.00 Benue Oftesi3 Brest duality diskettes storage cases omit.,

.DOons and paper urAucts sena for Pt cacao FREE yen your orderit 00 otheninse BONUS. Every catalog includes 515 00 worth of bonus70upOnS

PrIppin DISKETTES-Add 1300 per 100 Of IfECIr91HER ITEMS Snipping charges as shown in addrton:hews Payment VISA or MC COD orders add $300 Takes,ustomers ()lease add 84

Nationwide: 1-800-621-6827In Illinois: 1-312-944-2788

Minimum Order $3500WE WILL SEAT ANY NATIONALLY ADVERTISED FOOD

DRS WOOLENSuite 4806 30 East Huron Street Chicago iiiinois 60677

SYNCOMLAriuLt NU I T4' VII mrsmc trirummes I nip. umnuSeptember1984

iriuLt nitJ I l IUN mitt inir l/111Al runt unsmuI 23

Nutshell(Continued from page 52)

command as their means of entry.The menu's options are comprehen-

sive. The FIND, MODIFY, and DELETEcommands operate on the record beingdisplayed. The ADD command presents ablank data -entry screen for the additionof a new record.

The DEFINE and LAYOUT commandsare versatile and easy to use. When youinvoke DEFINE you are presented with ascreen that lets you start naming fields.After you have a field you give the datatype (text, numeric, date, etc.). Nutshellautomatically assigns a default length toeach field. I found that you cannot insertnew fields once a line has been entered,so prepare your layout on paper beforeyou commit yourself to putting it ondisk.

Perhaps the most powerful commandavailable from the Browse menu is LAY-OUT. Once you have defined your filestructure, Nutshell gives you great flexi-bility in determining how it is to be dis-played. Nutshell's full screen editor canbe used to create data -entry screens,data -display screens, and report layouts.Leading Edge claims that Nutshell has acapacity of two million layouts per file(provided there is sufficient disk space tohold them all). It is not at all difficult toconstruct layouts with headers, footers,

control breaks, totals and subtotals.The SORT command dosen't really

sort. Since all data fields are indexed, theuse of SORT creates a new index or index-es. When a file contains data, the recordsare presented in the order of originaldata entry until a sort is performed.Modified records are not reindexed untilyou are finished working with the filethat is being modified.

The PRINT command uses the layoutcurrently in use, but gives you the optionof switching to another. Once printinghas been started it can be stopped at anypoint and later restarted. You can alsomodify the print control options.

hi SummaryI found Nutshell to be easy to learn

and pleasant to use. A keyboard overlayincluded with the package saves con-stant searching through the manual (un-fortunately, there is no place to store theoverlay when you're not using it).

While the manual, at over 252 pages,is not trim, the individual pages are un-cluttered and well illustrated, althoughsome of the reproductions of screen im-ages are difficult to make out. The in-structions, however, are clear and pre-cise; the program should present no onewith any great difficulties. 0

BIGNGROUPSAVINGS

oSUBSCRIPTIONS

If you're part of agroup that uses microcomputersin school, the office or a usergroup, you may be eligible forsubstantial discounts to the world's

leading computer magazines!For more information, have a rep-

resentative contact!

Dan Rosensweig-212-503-5354Ziff -Davis Publishing Company

One Park Avenue -4th FloorNew York, NY 10016

A The Independent Guide For AppleComputing

COMPUTERS & ELECTRONICS

MICROSYSTEMS

11111 PC TECH JOURNAL

PCir, The Independent Guide To The IBMPCir In Education, Home and Business

A DISK, New Programs on Diskette ForApple II Series Computers

111. CREATIVE COMPUTING

PC, The Independent Guide To IBM Per-sonal Computers

PC DISK, New Programs on Diskette forthe IBM PC, PCXT, PCir and MostCompatibles

WORLD S LARGEST COMPUTER MAGAZ/ME

1111)11 e sti F L F R ON I CS

ADVERTISERS INDEX

RS no. ADVERTISER PAGE no.

50

926

32

2

Active Electronics 113Apple Computer Cover 2,1Atari 2Atari 89

BASF Cover 3

Casio, Inc 53Classified Advertising .... 118-123Cleveland Institute of

Electronics, Inc 18-2119 Communications Electronics 36-3733

7

146

6639

2410

41

10

21

2223

8

43

12

16

5

1

3840

43642

63

CompuServe 79Craftsman Corp 110

Digi-Key Corp. 116Discount Computers 106Discwasher 96Electronics Book Club 39-41Epson America, Inc. 13-15Epson America, Inc. 26-27Epson America, Inc. 51

Grantham Collegeof Engineering 110

Heath Co. 29-30Heath Co. 65Hewlett-Packard 32-33Hewlett-Packard 49

IBM Corporation 44-45ICS 114Information Unlimited 112Inmac 111

Jameco Electronics 115JDR Microdevices 117J & R Music World 111Jensen Tools 112

Koala Technologies Cover 4

Micro Exchange 25Micro Management

Systems, Inc. . 99Microsci 103

NRI Schools 8-11NRI Schools 97Nibble Notch

Computer Products 114Nicolet Paratronics Corp 107

Panasonic 5

Protecto . . 105

Radio Shack 59

Scottsdale Systems 107Sharp 7

Sintec 104Tam's Inc. 110

Western Union ..... 17

X' Int Diskette Products, inc... 102124

USE ONLY ONE CARD PER PERSON (Void after November 30, 1984)

sj Name

CE9843

aEtECt RON' C s

MN* IMIPTS MOM ENO If MO

14411 .11B fin

FREEINFORMATION:

Learning more about a productthat's advertised or mentioned inan article in this month's issue isas simple as one, two, three. Andabsolutely free.

1Print or type your nameand address on the at-tached card. Use only one

card per person.

2Circle the number(s) onthe card that correspondsto the number(s) at the

bottom of the advertisement orarticle for which you want moreinformation.

(Key numbers for advertisedproducts also appear in the Ad-vertisers' Index.)

3Simply mail the card, andthe literature will be mailedto you free of charge from

the manufacturer.

4To become a COMPUT-ERS & ELECTRONICSsubscriber, just check the

appropriate box at the bottom ofthe reply card. We'll put your sub-scription in the works immedi-ately. Consider what you'llgain-and save-if you pick thistime to become a subscriber. (It's$12.97 per year, 12 issues-asavings of 24%!)

Company Name (if applicable) Title

Address Phone( )

City State - 7ip(Zip Code must be included to unsure delivery.)

Please indicate which of the following microcomputers you currently own and/or plan to buy in thenext 12 months:

1.Own 2. Plan to Buy 1, Own 2. Plan to BuyApple A 0 L 0 Radio Shack/Tandy TRS-80 G 0 R 0Atari B 0 M 0 Texas Instruments H 0 S 0Commodore/PET . . . C 0 N 0 Timex Sinclair I 0 T 0Digital Equipment /DEC 0 0 0 0 Other (specify)Heath/Zenith E 0 KP 0 None

J

8U 0V 0

IBM F o o Ej3. For what, if any, business application(s) do you use the microcomputer you currently own?

Please send me 12 Issues of Computers a Electronics for $12.97 and bill me. (Full 1 yr.subscription price $16.97)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 2425 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 4849 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72

73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 9697 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120

121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140

USE ONLY ONE CARD PER PERSON (Void after November 30, 1984) CE9842

Name

Company Name (if applicable) Title

Address Phone(

City State Zip(Zip Code must be included to insure delivery.)

Please indicate which of the following microcomputers you currently own and/or plan to buy in thenext 12 months:

1.Own 2. Plan to Buy 1, Own 2. Plan to Buy&wile A 0 L 0 Radio Shack/Tandy TRS-80 G 0 R 0Atari B 0 M 0 Texas Instruments H 0 S 0Commodore/PET . C 0 N 0 Tmex Sinclair I 0 T 0Digital Equipment/DEC 0 0 0 0 Other (specify) J 0 U 0Heath/Zenith . E 0 P 0 None K 0 V 0IBM F to o 03 For what, if any, business application(s) do you use the microcomputer you currently own?

4. 0 Please send me 12 Issues of Computers a Electronics for 512.97 and bill me. (Full 1 yr.subscription price 916.97)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 2425 26 27 28 29 30 31 32 33 34 35 3E 37 38 39 40 41 42 43 44 45 46 47 4849 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72

73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 9697 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120

121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140

USE ONLY ONE CARD PER PERSON (Void after November 30, 1984)

Name

Company Name (if applicable) Title

CE9841

Addres.s_ Phone(

City State Zip(Zip Code must be included to insure delivery)

Please indicate which of tne following microcomputers you currently own and/or plan to buy in the'text 12 months:

1. Own 2. Plan to Buy 1, Own 2. Plan to BuyApple A 0 L 0 Radio Shack/Tandy TRS-80 G 0 R 0Atari B 0 M 0 Texas Instruments H ID S 0Commodore/PET . C 0 N C Timex Sinclair I 0 T 0Digital Equipment/DEC D 0 0 0 Other (specify) J 0 U 0Heath/Zenith E 0 P 0 None K 0 V 0IBM F 0 0 03. For what, if any, business application(s) do you use the microcomputer you currently own?

4. Please send me 12 Issues of Computers a Electronics for 512.97 and bill me. (Full 1 yr.

subscription price $16.97)1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

This address is for our product Free Infor- 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

mation Service only. Editorial inquiries 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72

should be directed to COMPUTERS & 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96

ELECTRONICS, One Park Avenue, New 97 98 99100101 102103104105106107108109110111 112 113 114 115 116 117 118 119 120

York, N.Y 10016. 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140

BUSINESS REPLY CARDFIRST CLASS PERMIT NO. 27346 PHILADELPHIA, PA

POSTAGE WILL BE PAID BY ADDRESSEE

WOU111 6 LAWN. C001"11.11.1.64101a

ni xt e s'.EL_ECT k oN S

P.O. Box 13877Philadelphia, PA 19101

BUSINESS REPLY CARDFIRST CLASS PERMIT NO 27346 PHILADELPHIA, PA

POSTAGE WILL BE PAID BY ADDRESSEE

WORLD 6 LAIIKAIT COMMIT.114411111.1

m m ersh.ELE i 0 N

P.O. Box 13877Philadelphia, PA 19101

BUSINESS REPLY CARDFIRST CLASS PERMIT NO. 27346 PHILADELPHIA, PA

POSTAGE WILL BE PAID BY ADDRESSEE

CoifliterskELECT P ON IC S

P.O. Box 13877Philadelphia, PA 19101

NO POSTAGENECESSARY

IF MAILEDIN THE

UNITED STATES

NO POSTAGENECESSARY

IF MAILEDIN THE

UNITED STATES

NO POSTAGENECESSARY

IF MAILEDIN THE

UNITED STATES

THE DO-IT-YOURSELFERS'

PROJECTASSISTANTBY TOM & KELDA RILEY

Make your own game controls...repairthat old joystick that's been sitting in yourcloset...have your project assistant in yourhome, ready to work when you are!

The COMPUTER CONTROLLERCOOKBOOK gives you complete schemat-ics and mechanical drawings for buildingand repairing game devices and controlsfor your Mare and Apples computer,with a special section showing you how toadapt these outlines to major machines.

Imagine building your own Super Joy-stick, Annunciator, Airplane Wheel, FootPedals, Sketch Pad or Multiple Connectorfrom purchased and scavenged parts, andthen using them on your home computer!You can save up to half the usual retailprice, and get up to double the life of mostcommercially purchased units!

Order the COMPUTER CONTROLLERCOOKBOOK today for hours of enjoymentand learning.Apple is a registered trademark of Appk Inc. Atari is aregistered trademark of Atari Inc.

ow

. 4

.0(..

C

ECREATIVE COMPUTING PRESSDept. NO5C, 39 East Hanover AvenueMorris Plains, NJ 07950Please send me COMPUTERCONTROLLER COOKBOOK(s) at S12.95plus $2.00 postage and handling each. OutsideU.S.A. add $3.00 per order. ssfiC.o Payment enclosed S____ 'Residents of

CA, NJ, and NY State add applicable sales tax.0 Charge my: American Express 0 Visa

8MasterCard

Card No Exp Dat.

Signature

Mr./Mrs /Msplease print name in fun

Address

City

State 7ip______For faster service, PHONE TOLL FREE

1-800-631-8112(In NJ call 201-540-0445)

0 Send me a FREE Creative Computing Press Catalog.

Llso available at your local bookstore or computer store.

BASF QUALIVIETRIC FLEXYDISKS.A GUARANTEED LIFETIMEOFOUTSTANDING PERFORMANCE.

BASF Qualimetric FlexyDisks feature a unique lifetime warranty,* firmassurance that the vital information you enter on BASF FlexyDisks todaywill be secure and unchanged tomorrow. Key to this extraordinarywarranted performance is the BASF Qualimetric standard...a totally new set of criteria against which all othermagnetic media will be judged.

You can count on BASF FlexyDisks because the Qua limetricstandard reflects a continuing BASF commitment toperfection in magnetic media. One example is theunique two-piece liner in our FlexyDisk jacket. ThisBASF feature traps damaging debris away fromthe disk's surface and creates extra space in thehead access area for optimum media -headalignment. The result is a guaranteedlifetime of outstanding performance.

For information security thatbridges the gap between todayand tomorrow, look for thedistinctive BASF package withthe Qualimetric seal. Call800-343-4600 for the nameof your nearest supplier.Circle No. 32 on Free Information Card

*Contact BASF for warranty details.

ENTER TOMORROW ON BASF TODAY.1983 BASF Systems Corp., Bedford, MA

BASF

0 BASF

A

KT2010

The Shortcut to Business ProductivityTouch and GoTired of typing in long computer com-mands? Let the Speed Key System takecontrol. The Speed Key System consistsof the KT 2010 touch tablet, Speed KeySoftware, and nine pre -configuredoverlays for Lotus 1-2-3';' WordStar,Visicalc', pfs:write', SuperCale;Multi Plan' dBase 11 DOSandBy placing an overlay on your touchtablet, Speed Key can reduce as manyas 80 keystrokes to a single push-buttoncommand. Now you can delete and in-sert paragraphs, or leap across spread-sheets in a single stroke.

How to MakeA Good Program GreatWith Speed Key, you can reprcgramkeys to fit your individual needs or createyour own custom overlays for almost anyof the hundrecs of IBM PC -DOSprograms.

But There's More...In cursor mode, Speed Key moves tn-scursor on the screen as you move yourfinger along the surface of the touchtablet. And yoi, don't need any moredesktop space than the tablet itself,about half the size of an 81/2 x 11 notepad.

Visit your Local Computer DealerTake a look at the Speed Key Systemwhich includes Speed Key Software KT 2010 Touch Tablet Speed KeyOwners Manual 9 Pre -ConfiguredTablet Overlays Blank Overlays. Or callus toll free, 800-KOA-BEAR.

Koala Technologies3100 Patrick Henry DriveSanta Clara, CA 95052-8100

CIRCLE 43 ON READER SERVICE CARD

The Speed Key System1-2-3'' and Lotus, are trademarks of Lotus Development Corporation. pis' :write is a registered trademark, of Software Publishing Corporation. SuperCalc' is a registered trademark ofSorcimCorporation. Microsoft' is a registered trademark of the Microsoft Logo. MS and MultiPlan are trademarks of Microsoft Corporation. Visicalc' is a registered trademark of Personal Software Inc.WordStar' is a registered trademark of MicroPro International Corporation. dBase is a trademark of ASHTON-TA-E. DOS versions for the IBM personal computer are registered trademarks ofInternational Business Machines Corporation and Microsoft Corporation. IBM Basic and IBM PC/XT are registered trademarks of International Business Machines Corporation