Mongolia International University

Chapter 5Chapter 5

B.M.HB.M.H

Input and OutputInput and Output

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Learning ObjectivesLearning Objectives

Computer ScreenComputer Screen CRT (Cathode Ray Tube)CRT (Cathode Ray Tube) LCD (Liquid Crystal Display)LCD (Liquid Crystal Display)

PrinterPrinter Impact printerImpact printer Nonimpact printerNonimpact printer

Voice outputVoice output Music output and other soundsMusic output and other sounds

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Computer systemComputer system

Input Processing Output

SecondaryStorage

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Output: information for Output: information for the userthe user

Computer outputComputer output screen screen printer outputprinter output voice voice sound sound various form of graphics outputvarious form of graphics output

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Computer ScreenComputer Screen

Monitor componentsMonitor components the housingthe housing for its electrical components for its electrical components a standa stand that can be tilted or swiveled that can be tilted or swiveled a screena screen

Screen outputScreen output Known in the computer industry as soft copyKnown in the computer industry as soft copy

Intangible and temporary

Hard copy Hard copy Output by printer on paper Tangible, permanent

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Computer ScreenComputer Screen

Types of screen technologyTypes of screen technology CCathode athode RRay ay TTube (CRT)ube (CRT)

The most common kind LLiquid iquid CCrystal rystal DDisplay (LCD)isplay (LCD)

Eletric beamEletric gun

Displayer

Red,Green,Blue

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Cathode Ray Tube (CRT)Cathode Ray Tube (CRT)

Types according to colorTypes according to color Most CRTs are colorMost CRTs are color Some are Some are monochromemonochrome

Only one color, usually green or amber (yellowish-brown color)

Less expensive than those with color

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CRTCRT

Technology Technology Called Called raster scanningraster scanning A process of sweeping electron beams A process of sweeping electron beams

across the back of the screenacross the back of the screen The backing of the screen displayThe backing of the screen display

Has a phosphorous coating that glows whenever it is hit by a beam of electron

The phosphorous does not glow for very long The image must be refreshed often

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CRTCRT

Phosphorous Phosphorous : (Symbol P) a chemical element found in : (Symbol P) a chemical element found in

several different forms, including as a several different forms, including as a poisonous, pale yellow substance that poisonous, pale yellow substance that shines in the dark and starts to burn as shines in the dark and starts to burn as soon as it is placed in airsoon as it is placed in air

Electron Electron : a very small piece of MATTER (= a : a very small piece of MATTER (= a

substance) with a negative electric CHARGE, substance) with a negative electric CHARGE, found in all atomsfound in all atoms

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CRTCRT

Scan rateScan rate The number of times the electron beam The number of times the electron beam

refreshed the screenrefreshed the screen 80 to 100 times per second80 to 100 times per second

Adequate to retain a clear screen image

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CRTCRT

Has hundreds of horizontal linesHas hundreds of horizontal lines scanned for left to right and from top to scanned for left to right and from top to

bottombottom Interlaced fashionInterlaced fashion

The odd-numbered lines on one pass of the electron beam And then the even-numbered lines on the next pass - a lower refresh rate without producing flicker - Inexpensive monitors - with text and fixed graphics displays

Noninterlaced (NI)Noninterlaced (NI) All lines are scanned on each pass- With animated graphics

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Computer ScreenComputer Screen

Is divided into dotsIs divided into dots Called Called addressableaddressable

they can be addressed individually by the graphics SW Each dotEach dot

Referred to as Referred to as a a picpicture ture elelement, ement, oror pixel pixel

Dot pitch Dot pitch the amount of space between the dotsthe amount of space between the dots

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( )

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Computer ScreenComputer Screen

The Resolution of the screen The Resolution of the screen the power of a computer screen to the power of a computer screen to

give a clear imagegive a clear image Factors relatedFactors related

the number of pixels on the screen The more pixels, the higher the resolution

Dot pitch The smaller the dot pitch, the better the quality of

the screen image

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Computer ScreenComputer Screen

ChipsChips affixed to the motherboard affixed to the motherboard Convert the electrical output signals of the Convert the electrical output signals of the

control unit into the signals that control the control unit into the signals that control the monitormonitor

To upgrade the graphics capabilityTo upgrade the graphics capability Most used Most used graphics cardgraphics card, or graphics adapter , or graphics adapter

board, plugged into a expansion slotboard, plugged into a expansion slot

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Graphic StandardsGraphic Standards

The intention of standardsThe intention of standards To agree on resolutions, colors and so forth To agree on resolutions, colors and so forth

to make it easier for the manufacturers of to make it easier for the manufacturers of PCs, monitors, graphics boards to ensure PCs, monitors, graphics boards to ensure that their products work togetherthat their products work together

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Graphic StandardsGraphic Standards

CGA (Color Graphics Adapter)CGA (Color Graphics Adapter) 320(horizontal)x200(vetrical) pixels320(horizontal)x200(vetrical) pixels

EGA (Enhanced Graphics Adapter)EGA (Enhanced Graphics Adapter) 640x350 pixels640x350 pixels

VGA (Video Graphics Array)VGA (Video Graphics Array) 640x480 pixels640x480 pixels

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Graphic StandardsGraphic Standards

The standards in most common use todayThe standards in most common use today SVGA (Super VGA)SVGA (Super VGA)

Provide different resolutionProvide different resolution 800(h)x600(v), 1024x768, 1280x1024, 1600x1200 pixels

Support a palette of 16million colorsSupport a palette of 16million colors But simultaneous colors which can be displayed is But simultaneous colors which can be displayed is

limited by the amount of video memory installed limited by the amount of video memory installed in a system in a system

XGA (eXtended Graphics Array)XGA (eXtended Graphics Array) High-resolution graphics standardHigh-resolution graphics standard The same resolution but more simultaneous colorThe same resolution but more simultaneous color Allows to be Allows to be noninterlacednoninterlaced

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Computer ScreenComputer Screen

Screen sizesScreen sizes Measured Measured diagonallydiagonally 15-or 17-inch screen : a typical office worker 15-or 17-inch screen : a typical office worker

handling word processing and spreadsheethandling word processing and spreadsheet 1 inch = 2.54 cm

19-inch screen : a user involved with high-19-inch screen : a user involved with high-powered graphicspowered graphics

Bigger is usually better, more expensiveBigger is usually better, more expensive

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Liquid Crystal Display Liquid Crystal Display (LCD)(LCD)

Flat-Panel ScreensFlat-Panel Screens Commonly used on laptop computersCommonly used on laptop computers Basic technologiesBasic technologies

Active-matrix Based on TFT (thin-film transistor technology) Brighter image Can be viewed from wider angles

Passive-matrix Fewer transistor cheaper, less power

Easy on the eyes; not flicker, brightly Easy on the eyes; not flicker, brightly shine onshine on

Higher price than CRTHigher price than CRT

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PrinterPrinter

A device that produces information on paper outputA device that produces information on paper output Two orientation settingsTwo orientation settings

Orientation : the direction in which an object facesOrientation : the direction in which an object faces Portrait modePortrait mode

Default setting Printed in a vertical alignment Suited for graphics images

Landscape modeLandscape mode Sideway or horizontally Useful for spreadsheets that have a lot of data across the sheet

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PrinterPrinter

Two ways of printing an image on paperTwo ways of printing an image on paper Impact printerImpact printer

Uses some sort of physical contact with paper to produce a image

Types Line printers : mainframe Dot-matrix printers : PC

Nonimpact printerNonimpact printer Places an image on a page without physically touching

the page Types

Laser printers Ink-jet printers

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PrinterPrinter

MeasureMeasure QualityQuality

dpi : Dots Per Inch 600 ~ 1200 dpi

SpeedSpeed ppm : Pages Per Minute 8 ~ 10ppm

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Impact printer

24x24, 10x10 Dot matrix

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Laser printersLaser printers

Use a light beam to help transfer Use a light beam to help transfer images to paperimages to paper

High-quality resultsHigh-quality results Today, print Today, print 600 or 1200 dpi600 or 1200 dpi

Print a page at a time at impressive Print a page at a time at impressive speedsspeeds Printing speeds of personal laser printers : Printing speeds of personal laser printers :

around 8 to 10 ppmaround 8 to 10 ppm Network printer : Network printer : 35 and 50 ppm35 and 50 ppm Banks and insurance useBanks and insurance use 1000ppm 1000ppm

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Data from computer→positive charged drum is neutralized →Toner sticked during passing by Toner→ Toner transferred to the paper →heat and pressure fuse the Toner to the paper → clean drum

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Ink-jet printersInk-jet printers

Spray in from multiple jet nozzlesSpray in from multiple jet nozzles Print in both black and white and Print in both black and white and

several different colors of inkseveral different colors of ink Low qualityLow quality, , not speedynot speedy Need a fairly high quality of paperNeed a fairly high quality of paper Cost : little more than a hundred dollarsCost : little more than a hundred dollars

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Ink-jet printersInk-jet printers

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Voice OutputVoice Output

Speech synthesisSpeech synthesis

The process of enabling machines to talk to peopleThe process of enabling machines to talk to people Accomplished through voice synthesizers (voice-Accomplished through voice synthesizers (voice-

output devices or audio-response units)output devices or audio-response units)

Two approaches to getting a computer to talkTwo approaches to getting a computer to talk Synthesis by analysis

The computer analyzes stored tapes of spoken words Synthesis by rules

The computer applies linguistic rules to create artificial speech Ex) airline, bus terminals, banks, Ex) airline, bus terminals, banks,

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Music Output and Other Music Output and Other SoundsSounds

SpeakerSpeaker Sound output devicesSound output devices

MultimediaMultimedia A certain kind of softwareA certain kind of software for good-quality software for good-quality software

Including Including multiple sight and sound effectsmultiple sight and sound effects An integrated collection of computer-based media An integrated collection of computer-based media

including text, graphics, sound, animation, photo including text, graphics, sound, animation, photo images and videoimages and video

Sound cardSound card Contain Contain sophisticated audio chipssophisticated audio chips Enhance the listening experience by varying the Enhance the listening experience by varying the

frequencies and timing of the sound wavesfrequencies and timing of the sound waves

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Sound card

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Music Output and Other Music Output and Other SoundsSounds

MIDIMIDI ( (MMusical usical IInstrument nstrument DDigital igital IInterface)nterface) A set of rulesA set of rules designed for connecting devices that designed for connecting devices that

produce and process digital music signalsproduce and process digital music signals DevicesDevices that conform to the MIDI standard that conform to the MIDI standard

Can communicate with each other and with a computer containing a MIDI interface

Two musical devicesTwo musical devices Can communicate via MIDI

The information exchanged between two MIDI The information exchanged between two MIDI devicesdevices

Is musical in nature Supported by many makers of PC sound cardsSupported by many makers of PC sound cards