12975_Input & Output Devices

8/2/2019 12975_Input & Output Devices

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Input & OutpDevices


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INTRODUCTION

Device: a device is a machine designed for a

purpose and can also defined a machine which

reduces human effort.


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DEVICES

Magnetic tapes

Magnetic disks

Optical disks

Digital video disk (DVD)

HolographicVersatile Disc (HVD)

Memory cards

Flash memory


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MAGNETIC TAPES

Sequential

secondary storage

medium

Primarily for storingbackups

Tapes similar to

audio and

videocassettes

Portion of tapes are

magnetized to

represent bits


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MAGNETIC DISKS

Direct access storage

medium

e.g. diskette, hard

disks Allows fast data

retrieval


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OPTICAL DISC

Data is recorded by

special lasers that

physically burn pits

in the disk. Data accessed

optical disc device

(compact disk

player) e.g. CD-ROM

740MB, CD-RW


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DVDAND HVD

DVD (Digital Video Disc)

Looks like a CD but more storage

capacity ~ 135min of digital video.

Software, video games, movies

HVD (Holographic Versatile Disc)

Advanced optical disk ongoing

research

Hold 200GB of data

Write data 10 times faster than

DVD


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MEMORY CARDS

Functions as a hard

disk drive

Portable, relatively

easy to use

Need to use memory

card reader/writer


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FLASH MEMORY

Asilicon computer chip

Keeps its memory when the power is

shut off

Flash the memory cell is erasedor reprogrammed in a single action

or flash

e.g. Migo keychain device, comes

with software that captures files andsettings from e-mail, word

processing, web browser,

presentation programs.


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INPUT AND OUTPUT DEVICES:THE

GATEWAY TO COMPUTER SYSTEMS

Through input and output devices, people pro

data and instructions to the computer and

receive results from it

Selection of input and output devices dependsorganizational goals and IS objectives


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CHARACTERISTICS AND FUNCTIONALITY

Nature of data- data can be human-readabl

machine-readable

Data entry: converts human-readable data in

machine-readable form Data input: transfers machine-readable data

into system

Source dataautomation: capturing and

editing data where the data is initially create

and in a form that can be directly input to a

computer


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INPUT DEVICES

Personal computer input devices

y Keyboard

y Mouse

Speech-recognition technology

y Input devices that recognize human speech

y e.g. automate account identification process

Digital cameras

Terminals

y Input and display devices that perform data entrand input at same time

y Office, warehouse, factory


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INPUT DEVICES (CONTINUED)

Scanning devices

Optical data readers

Special scanner

OMR standardized tests OCR convert handwritten to typed doc into digi

Magnetic stripe card

y Swipe card

Point-of-sale (POS) devicesy Used in retail operations to enter sales

information


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Magnetic ink character recognition (MICR)

devices

Asystem for reading banking data quickly

Use special ink readable by people and computer

e.g. bank check


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Automated teller machine (ATM) devices

Pen input devices

Touch-sensitive screens

Bar-code scanners Radio Frequency Identification (RFID)


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OUTPUT DEVICES

Display monitors

Liquid crystal displays (LCDs)

Organic light-emitting diodes (OLEDs)

Printers and plotters

Digital audio player


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SPECIAL-PURPOSE INPUT AND OUTPUT

DEVICES

Computer-based navigation systems

y GPSs (Global positioning system), satellite based

radio navigating system

y Guide to specific destination

Multiple function printers

y Print, copy, fax,scan

Eyebud screens

y Portable media devices

y Display video in front of one eye


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COMPUTER SYSTEM TYPES, SELECTION

AND UPGRADING

Computer classification:

Special-purpose computers: used for limit

applications by military and scientific researc

groups General-purpose computers:

y used for a wide variety of applications

y Single user at a time, multiple concurrent users


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COMPUTER SYSTEM TYPES

Handheld computers single user, small size

portable

Portable computers

laptops, notebooks, tablet

Thin client

y Low-cost, no extra drives, limited capabilities Desktop computers


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COMPUTER SYSTEM TYPES (CONTINUED

Workstations more powerful than personal

computer, similar size to desktop, heavy

mathematical computing, CAD.

Servers to perform special tasks, e.g. runninnetwork or Internet application.


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COMPUTER SYSTEM TYPES (CONTINUED

Mainframe computers large, powerful compushared by hundreds of concurrent users, conne

via terminals

Supercomputers

y most powerful computers, fastest processing speehighest performance.

y Special purpose machines weather forecast, mil

application, simulation of golf club designs.


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SUMMARY

Examples of input devices: keyboards, mouse

voice-recognition devices, terminals, scanning

devices, and touch-sensitive screens

Examples of output devices: display monitorsliquid crystal displays (LCDs), printers


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Principles of Information Systems

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Documents

12975_Input & Output Devices