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INPUT AND OUTPUT

© 2005 The McGraw-Hill Companies, Inc. All Rights Reserved.

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Competencies

Define input

Describe keyboard entry, pointing devices, & scanning devices

Discuss image capturing devices, digitizing devices, & audio input devices


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Competencies cont.

Define output

Describe monitors, printers, and audio output devices

Discuss combination input & output devices


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What is Input?

Any data or instructions used by a computer

Input devices( are hardware use to translate word, sound, images, and actions that people understand into a form that the

system unit can process.Hardware

Keyboards

Mice

Scanners

Other devices


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Keyboard Entry

KeyboardsTraditional keyboards

Flexible keyboards (easy packing or storage)Ergonomic keyboards (palm rest is provided)Wireless keyboards( transmit input to the system unit through the air) PDA keyboards

FeaturesTypewriter keyboard with numeric padSpecial purpose keysToggle and combination keys (caps.


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Flexible keyboards

Ergonomic keyboards

Wireless keyboards

PDA keyboards


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Traditional Keyboard

Computer hardware Keyboard.htm


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Pointing Devices

MouseMechanicalOptical

(use light to detect mouse movement)

Cordless or wirelessUse radio waves or infrared to communicate with the system

Joystick (used for computer games)

Touch Screen ( clear plastic outer layer. Behind this layer are crisscrossed invisible beams of IR light- used in restaurant and ATM)

Light Pen ( light sensitive pen- edit digital images)


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Mechanical Mouse Optical Mouse Wireless Mouse

Joystick Touch Screen


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Scanning DevicesConvert scanned text and images into a form that the system unit can process

1- Optical scanners: recognize light, dark and colored area

Flatbed ( like a copy machine-

Portable (handheld device)

2- Bar code readers: • handheld wand reader or platform• Used in grocery stores.• Contain photoelectric cells that scan or read bar codes.• Universal product code.(UPC)


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Scanning Devices

3- Character and mark recognition devices

Scanners that recognize special characters & marks

Magnetic ink character recognition (MICR)Used in bank to read unusual numbers on the bottom of the checks

Optical-character recognition (OCR)Preprinted character that can be read by a light source

Optical-mark recognition (OMR)Score multiple-choice


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Optical flatbed

Optical Portable : Up to 1000 pages of scanned text can be stored in the pen and transferred to PC,

Bar code reader

MICR

OMR


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Image Capturing Devices

Digital cameraImages recorded digitally on a disk

Images can be downloaded to a computer

Digital video camera Records motion digitally

Can take still images as well

WebCamsSpecialized digital video cameras

Broadcast images over the Internet


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Digitizing Devicesconvert a sketch or figure into a form that can be processed by a computer

Graphics Tabletsuse special graphic surface and special stylus or pen-like device

Digital Notepads Use regular notepad and pen


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Audio Input Devices convert sound into a form that can be processed by the system unit.

VoiceVoice recognition systems

Use a microphone, a sound card and special software.

Two types of voice recognition:

Discrete-speech recognition systems Are able to recognize individual words based on their sound. Can not distinguish between same-sound words like there, their

Continuous-speech recognition systemCan distinguish between same-sound words like there, their

Music Musical Interface Digital Interface (MIDI)

Allow musical instruments to connect to the system unit using MIDI ports


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What is Output?

Processed data or information

Types of outputText

Graphics

Audio & video

Output devicesAre any hardware used to provide or create output

from the computer. They translate information that has been processed by the system unit into a form that human can understand.

Monitors

Printers


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MonitorsKnown as screens or display screensOutput referred to as soft copy Features

Resolution Images are formed on a monitor by a series of dots or pixels( picture

elements) . Resolution is expressed as a matrix of dots or pixels (1280cx1024R) The higher a monitor’s resolution (the more pixels).

Dot pitch: Is the distance between each pixel. Monitors have a dot distance of 3.1 mm. The lower the dot pitch the higher the clarity of images produced.


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Refresh rate Indicates how often a displayed image is updated or refresh. Most monitors operate at 75 Hz, the monitor updated 75 times each

second. The faster the refresh rate the better the quality of images.

Size Measured by the diagonal length of a monitor’s viewing area. The smaller the monitor the better the quality of images displayed.

Cont


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More on Monitors

Cathode-ray tube or CRTs

Flat-panelLiquid crystal display (LCD)

Portable and thinner than CRTs

Other monitorsE-books

Data projectors

High-definition television (HDTV)


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Flat panel

Cathode ray tube


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E-book readerData projector

HDTV


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Printers

Translates information that has been processed by the system unit.Output referred to as hard copyFeatures

ResolutionMeasured in dpi, the higher the dpi the better the quality of

image producedColor capability : black ink or colorSpeed: Measured in the number of pages printed per minuteMemory: used to store printing instructions and documents waiting to be printed.


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Printers

Ink-jet printer Spray ink at high speed onto the surface of paper

Laser printerPersonal laser printers

Shared laser printers

Thermal printer

Other printersDot-matrix

Plotters

Photo printers


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Ink-jet printerLaser printer

Thermal printer

Dot-matrix printer

plotter


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Audio Output Devices

Translates audio information into sounds that people can understand

Common devicesSpeakers

Headphones


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Combination Input and Output Devices

Fax machinesDevice for sending and receiving images over telephone line

Multifunction devicesCombine the capabilities pf scanner, printer, fax and copying machine.

Internet telephonesTelephony

Voice-over IP (VoIP)Specialized I/O device for receiving and sending voice communication over

computer networks and internet.


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FAX machine

Internet telephone

MFD


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Terminals

An input and output device that connects you to a mainframe or other type of computer called server

Types of terminalsDumb terminal

It cant process date used onlty to gain access to information from a computer( airline reservations)

Intelligent terminal : process data

Network terminal: no hard-disk

Internet terminal: access internet without a microcomputer


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A Look to the FutureNeural Signals Inc.

Brain machine interface

Allows humans to control machines with their thoughts

Individuals incapable of communication

Physically immobile people


HW3Explain ( definition, picture, details) about two devices one for entry(I/P device) and another for Exit( O/P device) that had not been mentioned in this chapter.

Last date: next week 3rd January

Class test : Next lecture

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Key Terms

active matrix monitor (190)audio input device (185) audio-output device (193) bar code (183)bar code reader (183) bar code scanner (183)cathode ray tube monitor (CRT) (189)

character recognition device (183)

clarity (189)

color capability (printer) (191)

combination device (193)

combination key (175)

continuous-speech recognition system (188)


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Key Terms

cordless mouse (180)data projector (190)digital camera (184)digital notepad (185)digital video camera (184)digitizing device (185)discrete-speech recognition system (188)display screen (189)

dot-matrix printer (192)dot pitch (189)dots-per-inch (dpi) (191)download (184)dual-scan monitor (190)dumb terminal (195)e-book (190)e-book reader (190)


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Key Terms

facsimile (fax) machine (194)

flat-panel monitor (190)

Flatbed scanner (183)

graphics tablet (185)

hard copy (191)

Headphones (193)

high-definition television (HDTV) (190)

host computer (195)

image capturing device (184)

ink-jet printer (191)

input device (178)

input (178)

intelligent terminal (195)

Internet telephone (194)

Internet telephony (194)


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Key Terms

Internet terminal (195)

IP Telephony (194)

joystick (181)

keyboard (178)

laser printer (192)

light pen (182)

liquid crystal display (LCD) (190)

Magnetic-ink character recognition (MICR) (183)

mark recognition device (183)

mark sensing (183)

mechanical mouse (180)

memory (printer) (191)

Musical Interface Digital Interface MIDI (188)


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Key Terms

MIDI device (188)

monitor (189)

mouse (180)

mouse pad (180)

mouse pointer (180)

multifunction device (MFD) (194)

network computer (195)

network terminal (195)

numeric keypad (178)

optical character recognition (OCR) (183)

Optical-mark recognition (OMR) (183)

optical mouse (180)

optical scanner (182)

output (188)

output device (188)


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Key Terms

passive-matrix monitor (190)

PC/TV (190)

personal laser printer (192)

photo printer (192)

pixel (picture element) (189)

platform scanner (183)

plotter (192)

pointing (180)

pointing device (180)

pointing stick (180)

portable scanner (183)

printer (191)

reader/sorter (183)

refresh rate (189)

resolution (monitor)(189)


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Key Terms

resolution (printer) (191)

roller ball (180)

scanner (182)

scanning device (182)

screen (189)

server (195)

shared laser printer (192)

size (viewable size) (189)

soft copy (189)

speakers (193)

speed (printer) (191)

telephony (194)

terminal (195)

thermal printer (192)

thin client (195)

thin film resistor monitor (TFT) (190)

toggle key (179)


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Key Terms

touch pad (180)

touch screen (181)

touch surface (180)

trackball (180)

Universal Product Code (UPC) (183)

voice recognition system (185)

voice-over IP (VoIP) (194)

wand reader (183)

Web appliance (195)

WebCam (184)

Web camera (184)

Web terminal (195)

wireless mouse (180)


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FAQs

What are pointing devices?

I would like to insert several images in a document. How can I capture the images?

What are digitizing devices?

What is voice recognition?

What is the difference between a CRT and an LCD display?

What is HDTV?


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Discussion Questions

Describe the three different mouse types designed for input.

How does Internet telephony work? Discuss.

Discuss the features of multifunctional devices.

Describe the features of a monitor that help to make images appear clearer on the screen.

What are MIDI devices and how are they used?

Documents

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