Chapter 5

InputUsers submit input dataOutputUsers get processed information

Data from the user to the computerConverts raw data into electronic form

TraditionalLooks like typewriter with extra keysNon-traditionalFast food restaurantsEach key represents a food item rather than a character

Function KeysGive commandsSoftware specificMain KeyboardTypewriter keysSpecial command keys

Numeric KeysNum Lock toggle On numeric data & math symbolsOff cursor movementCursor Movement Keys

Position a pointer / cursor on the screenControls drawing instruments in graphics applicationsCommunicate commands to a program

TypesMechanicalOpticalWirelessFeaturesPalm-sized1 or 2 buttonsWheel

TrackballUpside-down mouseBall on topRoll ball with handLaptop computersTouchpadPressure-sensitive padCursor moves as you slide your fingerLaptop computers

Pointing stickPressure-sensitive postMounted between G and H keys on keyboardApply pressure in a direction to move cursor

JoystickShort leverHandgripDistance and speed of movement control pointer position

Digitizing tabletRectangular boardInvisible grid of electronic dotsWrite with stylus or puckSends locations of electronic dots as stylus moves over themCreates precise drawingsArchitects and engineers

Human points to a selection on the screenTypesEdges emit horizontal and vertical beams of light that crisscross the screenSenses finger pressureLight pen for pointing

KiosksSelf-help stationsEasy to use

Where foundMallsDisney WorldGovernment offices

Small hand-held devicesElectronic pen (stylus)PointerHandwritten inputPersonal Digital Assistants (PDA)

Special equipment to collect data at the sourceSent directly to a computerAvoids need to key dataRelated input areasMagnetic-Ink Character RecognitionScannersOptical recognition devicesVoice

Read characters made of magnetic particlesNumbers on the bottom of checksMICR inscriber adds characters to check that show amount cashed

Optical recognitionLight beam scans input dataMost common type of source inputDocument imaging converts paper documents to electronic formConverts snapshots into imagesConverts scanned picture into characters OCRExact computer-produced replica of original

FlatbedOne sheet at a timeScans bound documentsSheetfeedMotorized rollersSheet moves across scanning headSmall, convenient sizeLess versatile than flatbedProne to errors

HandheldLeast expensiveLeast accuratePortableUser must move the scanner in a straight line at a fixed rateWide document causes problems

Photoelectric deviceReads bar codesInexpensiveReliableWhere Used?Supermarket UPCFederal Express

Speech RecognitionSpeech recognition devicesInput via a microphoneVoice converted to binary codeProblemsSpeaker-dependentVoice training

Changing radio frequencies in airplane cockpitsPlacing a call on a car phoneRequesting stock-market quotations over the phoneCommand from physically disabled users

Information for the userTypesScreen soft copyPrinter hard copyVoiceSoundGraphics

Data that is entered appears on the screenScreen is part of the monitor

Cathode Ray Tube (CRT)

Flat panel displayLiquid Crystal Display (LCD)

Raster scanningSweeping electron beams across the back of the screenPhosphorous coating on backGlows when hit by a beam of electronsPhosphorous loses glow and image fades and flickersImage must be continually refreshed

Refresh rate / scan rateNumber of times electron beams refreshes the screen80-100 times per second adequate for clear screen imageProcess also used for television

Color vs. MonochromeColorTypical monitor sold todayMonochromeGreen or amber on a contrasting backgroundLess expensive than color

SizeMeasured diagonallyTypical sizesOffice user: 15-17 inchHigh-powered graphics user: 19 inchHigh-end monitors: 21 inches and upLarger sizeMore expensiveMore space on desktopReduces eye strain

Liquid Crystal Display (LCD)Primarily on laptopsMoving to desktopSkinny (depth) regardless of size

Crisp, brilliant imagesEasy on eyesNo flickerFull dimension is useableMore expensive that CRT monitors

Active MatrixThin-film transistor technology (TFT)Transistors for each pixelBrighter imageViewable from an anglePassive MatrixFewer transistorsCheaperLess power

Produces information on paperOrientationPortraitLandscapeMethods of printingImpactNonimpact

Line printerOne line at a timeHigh volumeLow qualityDot-matrix printerOne character at a time

Transfers images to paper using a light beamPrints one page at a time600-1200 dpi High qualitySpeedPersonal laser printers: 8-10 ppmNetwork laser printers: 35-50 ppmHigh-volume laser printers: up to 1000 ppmBlack and white / color

Spray ink at paperBlack and white / colorLow costNeed high quality paperSlower than laser

Creates multimedia outputMultiple sight and sound effects

SpeakersSound card

Enables machines to talk to peopleTypesVoice synthesizersVoice output devicesAudio-response unitsConvert data in storage to vocalized soundsSynthesis by analysis human sounds are stored and reproduced as neededSynthesis by rule creates artificial speech

UsesAutomobilesTelephone surveysCatalog order is readyYour payment is late reminder

BusinessEducationScienceSportsComputer artEntertainment

TypesMapsChartsHelpCompare dataSpot trendsMake decisions quicklyAttention-gettingUpdated instantaneouslyRendered quickly

Animated graphicsPrepared one frame at a timeExamplesCartoonsCommercials without humansTelevision networks logoArcade games

*Enter

Sec 11*