Input and OutputInput and Output

The User ConnectionThe User Connection

Input-Getting Data From the Input-Getting Data From the UserUser

Some data such as a scanned Some data such as a scanned bar code or speech that is bar code or speech that is spoken to the computer can go spoken to the computer can go directly for processingdirectly for processing

Some input must go through Some input must go through intermediate handling such as intermediate handling such as translating a translating a source documentsource document into machine readable datainto machine readable data

KeyboardKeyboard

Standard keyboardsStandard keyboards are common are common input devices on computersinput devices on computers

Specialized keyboardsSpecialized keyboards exist such as exist such as fast food restaurant ordering fast food restaurant ordering systemssystems

Cordless keyboardsCordless keyboards use a battery use a battery powered transmitter instead of a powered transmitter instead of a cord to transfer data to the computercord to transfer data to the computer

Ergonomic keyboardsErgonomic keyboards are specially are specially designed for a natural position of the designed for a natural position of the handshands

ErgonomicsErgonomics

A field of study concerned with A field of study concerned with healthy, comfortable, efficient healthy, comfortable, efficient interactions between people and interactions between people and machinesmachines

RSI-repetitive strain injuryRSI-repetitive strain injury can be can be sustained from doing the same thing sustained from doing the same thing over and over such as typing. over and over such as typing. Ergonomically designed keyboards Ergonomically designed keyboards can lessen these injuriescan lessen these injuries

Pointing DevicesPointing Devices

Allows user to point, set the Allows user to point, set the insertion point, or click insertion point, or click something to issue a commandsomething to issue a command

MouseMouse MechanicalMechanical OpticalOptical CordlessCordless

Other Pointing DevicesOther Pointing Devices

TrackballTrackball -variation on a mouse -variation on a mouse where you move the ball and the where you move the ball and the device stays stilldevice stays still

TouchpadTouchpad -pressure sensitive -pressure sensitive area that you physically touch to area that you physically touch to give commands; common on give commands; common on laptopslaptops

JoystickJoystick -lever with a handgrip -lever with a handgrip

Even More Pointing DevicesEven More Pointing Devices

Graphics Tablet or Digitizing Tablet- Graphics Tablet or Digitizing Tablet- invisible grid of electronic dots that invisible grid of electronic dots that are activated by a pen-like stylus or are activated by a pen-like stylus or a pucka puck

Touch screensTouch screens - beams of light - beams of light emitted from edge of screen can emitted from edge of screen can determine when a user touches the determine when a user touches the screen by the broken beams or can screen by the broken beams or can use a light penuse a light pen

Pen based computingPen based computing -uses a stylus -uses a stylus to select items; common in handheld to select items; common in handheld devicesdevices

Source Data AutomationSource Data Automation

Use of special equipment to Use of special equipment to collect data at its sourcecollect data at its source

Does not require re-keying Does not require re-keying which eliminates mistakeswhich eliminates mistakes

Three primary areas:Three primary areas: Magnetic Ink Character Magnetic Ink Character

Recogniton (MICR)Recogniton (MICR) ScannersScanners Other Optical MethodsOther Optical Methods

MICRMICR

Uses a machine to read Uses a machine to read characters written in an ink characters written in an ink made of magentized particlesmade of magentized particles

Common example is check Common example is check numbers at the banknumbers at the bank

MICR inscriberMICR inscriber writes writes information using the special inkinformation using the special ink

ScannersScanners

Optical scanners, now just scanners, Optical scanners, now just scanners, convert text or drawings into convert text or drawings into machine readable formatmachine readable format

Using Optical Recognition, a light Using Optical Recognition, a light beam scans the item and changes it beam scans the item and changes it into electrical impulses for into electrical impulses for processingprocessing

Common example is the bar code Common example is the bar code readerreader

Document ImagingDocument Imaging

Process of converting paper Process of converting paper copies to computer copies copies to computer copies

Can be stored on disk instead of Can be stored on disk instead of file cabinetsfile cabinets

Less expensiveLess expensive More efficientMore efficient

Types of ScannersTypes of Scanners

A flatbed scanner scans one sheet at A flatbed scanner scans one sheet at a time by laying the sheet face down a time by laying the sheet face down on the bed of the scanneron the bed of the scanner

Sheetfed scanner use motorized Sheetfed scanner use motorized rollers to feed the document across rollers to feed the document across the scanning mechanismthe scanning mechanism

Handheld scanner-portable device Handheld scanner-portable device that requires users to pass the that requires users to pass the scanning element over the item to be scanning element over the item to be scannedscanned

More Optical Recognition More Optical Recognition MethodsMethods

Optical mark recognition (OMR)- Optical mark recognition (OMR)- searches for and recognizes searches for and recognizes marks such as a scantron testmarks such as a scantron test

Optical Character Recognition Optical Character Recognition (OCR) – uses a wand reader to (OCR) – uses a wand reader to scan and process standardized scan and process standardized letters (OCR-A) many times on letters (OCR-A) many times on things such as sales tagsthings such as sales tags

Some More Optical Some More Optical Recognition MethodsRecognition Methods

Bar codes-each product has a Bar codes-each product has a unique product code (UPC) unique product code (UPC) represented by a pattern of barsrepresented by a pattern of bars

Bar code scanner scans the Bar code scanner scans the bars using reflected light which bars using reflected light which is then processed to retrieve is then processed to retrieve product information assigned to product information assigned to that bar codethat bar code

Handwriting RecognitionHandwriting Recognition

Voice InputVoice Input

Also called speech recognitionAlso called speech recognition Speech accepted through Speech accepted through

microphone and converted into microphone and converted into binarybinary

Can be used to control the Can be used to control the operation of the computer or to operation of the computer or to enter data through dictationenter data through dictation

Two Types of Speech Two Types of Speech RecognitionRecognition

Discrete word systems-limited Discrete word systems-limited number of recognized words; must number of recognized words; must pause between words; very accuratepause between words; very accurate

Continuous word systems-allows Continuous word systems-allows almost normal rate of speech and almost normal rate of speech and recognizes many more words; less recognizes many more words; less accurate; comes in some of the accurate; comes in some of the newer application software packages newer application software packages such as Office XPsuch as Office XP

Digital CamerasDigital Cameras

Image is stored on a chip in the cameraImage is stored on a chip in the camera Can be viewed immediately without Can be viewed immediately without

processingprocessing Pixels-tiny dots that compose a digital Pixels-tiny dots that compose a digital

imageimage Resolution measures the quality of the Resolution measures the quality of the

images by the number of pixels per inchimages by the number of pixels per inch Many use removable flash cards for Many use removable flash cards for

storagestorage Images must be downloaded to a computer Images must be downloaded to a computer

by connecting the camera to the computer by connecting the camera to the computer and transferring the imagesand transferring the images

Digital VideoDigital Video

Consists of a series of still images or Consists of a series of still images or framesframes

Can be captured by an inexpensive Can be captured by an inexpensive web camweb cam

Video capture cards allow you to Video capture cards allow you to translate TV and older video into a translate TV and older video into a format your computer can recognizeformat your computer can recognize

Newer video cameras actually record Newer video cameras actually record the video digitally which allows you the video digitally which allows you to transfer video straight to the to transfer video straight to the computercomputer

Output : Information for the Output : Information for the UserUser

Most common form is output to Most common form is output to the screen or printerthe screen or printer

Other types include voice, Other types include voice, sound, graphics and even sound, graphics and even smellssmells

Screen TechnologyScreen Technology

Screen is part of the monitor, Screen is part of the monitor, the housing which also holds the the housing which also holds the electrical componentselectrical components

Screen output is known as “soft Screen output is known as “soft copy” because it is not copy” because it is not permanentpermanent

““Hard copy” like a printout, is Hard copy” like a printout, is tangible tangible

CRTCRT

Stands for cathode ray tubeStands for cathode ray tube Most common variety of monitorMost common variety of monitor Most are color but some are Most are color but some are

monochrome, meaning they can monochrome, meaning they can only show one color (usually only show one color (usually yellow or green)yellow or green)

Monochrome are less expensive Monochrome are less expensive and used in some business and used in some business environmentsenvironments

How the CRT worksHow the CRT works

Uses a technology called raster Uses a technology called raster scanningscanning

An electron beam sweeps across the An electron beam sweeps across the back of the screen covered in back of the screen covered in phosphorous that glows when hit by phosphorous that glows when hit by lightlight

It doesn’t glow very long so it must It doesn’t glow very long so it must be refreshedbe refreshed

The scan rate is the number of times The scan rate is the number of times the screen is refreshed, generally 75 the screen is refreshed, generally 75 times per second in a quality monitortimes per second in a quality monitor

More on the monitorMore on the monitor

Monitor is divded into dots that Monitor is divded into dots that are individually addressable and are individually addressable and can be set to glow at a certain can be set to glow at a certain brightness and a certain colorbrightness and a certain color

Dots are called picture elements Dots are called picture elements or pixels.or pixels.

Quality of a monitorQuality of a monitor

Resolution on a screen is Resolution on a screen is measure of screen clarity and is measure of screen clarity and is related to the number of pixels related to the number of pixels on the screenon the screen

Higher resolution = more pixelsHigher resolution = more pixels Dot pitch is the space between Dot pitch is the space between

pixelspixels Smaller dot pitch=sharper imageSmaller dot pitch=sharper image

Graphics CardsGraphics Cards

The Control Unit of the CPU The Control Unit of the CPU controls the signals sent to the controls the signals sent to the monitor via the graphics card or monitor via the graphics card or the graphics adapter boardthe graphics adapter board

The card is plugged into an The card is plugged into an expansion slot on the expansion slot on the motherboardmotherboard

Standards for MonitorsStandards for Monitors

Standards were developed early Standards were developed early to define resolutions and colorsto define resolutions and colors

Most common standard today is Most common standard today is SVGA (Super Video Graphics SVGA (Super Video Graphics Adapter)Adapter)

Supports a variety of resolutions Supports a variety of resolutions and over 16 million colorsand over 16 million colors

Video MemoryVideo Memory

High speed form of RAM High speed form of RAM installed on the graphics cardinstalled on the graphics card

Allows more colors to be Allows more colors to be displayed on the screen at oncedisplayed on the screen at once

Separate from main memory Separate from main memory and stores the image and stores the image temporarily from the CPUtemporarily from the CPU

Is bigger better?Is bigger better?

The size of a CRT is called the VIS, The size of a CRT is called the VIS, viewable image sizeviewable image size

Not necessarily the spec given at the Not necessarily the spec given at the computer store. A 17” monitor may only computer store. A 17” monitor may only have a 16” vishave a 16” vis

In other words, it measures across the In other words, it measures across the screen diagonally and only includes the screen diagonally and only includes the glass partglass part

More expensiveMore expensive Takes up more spaceTakes up more space Easier on eyesEasier on eyes Good for graphicsGood for graphics

Flat panel screensFlat panel screens

LCD or liquid crystal display is LCD or liquid crystal display is used commonly on small used commonly on small devices such as cell phonesdevices such as cell phones

Getting larger and starting to Getting larger and starting to appear in the desktop marketappear in the desktop market

Flat panels maintain their Flat panels maintain their “skininess” even as the screen “skininess” even as the screen grows in size unlike CRT which grows in size unlike CRT which grow deeper as size increasesgrow deeper as size increases

Flat Screen TechnologyFlat Screen Technology

Active matrix-based on TFT Active matrix-based on TFT (thin flim transistor)(thin flim transistor)

Passive matrix uses fewer Passive matrix uses fewer transistors but produces a transistors but produces a brighter imagebrighter image

Gas plasma a newer more Gas plasma a newer more expensive technology with expensive technology with screen sizes up to 60 inchesscreen sizes up to 60 inches

Smart DisplaysSmart Displays

Based on flat panel technologyBased on flat panel technology Runs Windows CERuns Windows CE Touch screenTouch screen Allows users to access other Allows users to access other

computerscomputers Contains own wireless Contains own wireless

transmitter and processortransmitter and processor

PrintersPrinters

Produce output on paperProduce output on paper Two modes:Two modes:

LandsacapeLandsacape PortraitPortrait

Two types of printers:Two types of printers: Impact Impact Non-impactNon-impact

Impact PrintersImpact Printers

Print device actually touches or Print device actually touches or impacts paperimpacts paper

Line printers-fast printers usually Line printers-fast printers usually associated with mainframes.associated with mainframes.

Dot-matrix printers-can print Dot-matrix printers-can print through mulitple formsthrough mulitple forms

Overall, slower, lower quality, Overall, slower, lower quality, and don’t last as longand don’t last as long

Non-impact printerNon-impact printer

Print device doesn’t actually Print device doesn’t actually touch the papertouch the paper

Generally more expensiveGenerally more expensive Higher quality graphicsHigher quality graphics Generally faster than impact Generally faster than impact

printersprinters

Laser printersLaser printers

Non-impact printer that uses light to Non-impact printer that uses light to transfer image to papertransfer image to paper

Normal print 8-10ppmNormal print 8-10ppm Network print 35-50ppmNetwork print 35-50ppm High end printers print up to 1,000 High end printers print up to 1,000

ppmppm High quality, usually 600-1200dpiHigh quality, usually 600-1200dpi Color laser printers much more Color laser printers much more

expensiveexpensive

Inkjet PrintersInkjet Printers

Spray ink onto pageSpray ink onto page Slower than laserSlower than laser Generally lower qualityGenerally lower quality However, affordable color printing at However, affordable color printing at

pretty good qualitypretty good quality Three colors combine to make all Three colors combine to make all

colorscolors With inkjet and laser, can result in With inkjet and laser, can result in

some colors not true color of imagesome colors not true color of image

Voice OutputVoice Output

Speech synthesis allows Speech synthesis allows computer to produce speech as computer to produce speech as outputoutput

Voice synthesizers, aka voice Voice synthesizers, aka voice output devices or audio output devices or audio response units transfer data in response units transfer data in storage to recognizable speechstorage to recognizable speech

Two types of synthesisTwo types of synthesis

Synthesis by analysis-replays Synthesis by analysis-replays recorded human speech as recorded human speech as needed. Sounds natural but needed. Sounds natural but pace is sometimes awkwardpace is sometimes awkward

Synthesis by rule-creates Synthesis by rule-creates artificial speech that does not artificial speech that does not sound like a real humansound like a real human

Music outputMusic output

MIDI-Musical Instrument Digital MIDI-Musical Instrument Digital InterfaceInterface

Allows musical instruments and Allows musical instruments and synthesizers to be connected to synthesizers to be connected to computercomputer

Shares data with computer Shares data with computer regarding pitch, length of notes, regarding pitch, length of notes, volume and other musical volume and other musical attributesattributes

MicroformMicroform

Computer Output Microform Computer Output Microform produces small images on produces small images on microfiche or microfilmmicrofiche or microfilm

Microfilm is a roll or imagesMicrofilm is a roll or images Microfiche more resembles a Microfiche more resembles a

cardcard Can store up to 1,000 images Can store up to 1,000 images

per roll or ficheper roll or fiche

Combining Input and OutputCombining Input and Output

Terminal-combines input and output, Terminal-combines input and output, usually monitor and keyboardusually monitor and keyboard

Dumb terminal-has no processing abilities Dumb terminal-has no processing abilities and just sends data back and forth to and just sends data back and forth to another computeranother computer

Intelligent terminal-keyboard, monitor, Intelligent terminal-keyboard, monitor, memory and processor that can perform its memory and processor that can perform its own processingown processing

POS or point of sale terminal used mainly POS or point of sale terminal used mainly in retail markets. For example, in grocery in retail markets. For example, in grocery store bar code scanner with display store bar code scanner with display monitor, receipt printermonitor, receipt printer

Computer GraphicsComputer Graphics

Business graphics-charts, Business graphics-charts, graphs, and mapsgraphs, and maps

Allow visual presentation of dataAllow visual presentation of data Easy to spot trends and make Easy to spot trends and make

decisionsdecisions

Video GraphicsVideo Graphics

Graphics associated with Graphics associated with moving imagesmoving images

AnimationsAnimations Special EffectsSpecial Effects Video gamesVideo games

CAD/CAM/CIMCAD/CAM/CIM

Computer Aided DesignComputer Aided Design Computer Aided ManufacturingComputer Aided Manufacturing Creates two and three dimensional Creates two and three dimensional

modelsmodels Designs products and allows for Designs products and allows for

theoretical testing by softwaretheoretical testing by software CAM controls production processCAM controls production process Computer Integrated Manufacturing Computer Integrated Manufacturing

is the integration of both CAD and is the integration of both CAD and CAMCAM