module 1 - intro to computers and it

7/30/2019 Module 1 - Intro to Computers and IT

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Introduction to Computers

and Information Technology

Module 1


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Evolving more rapidly than Industrial Age

Will continue into the current century

Information Age


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Cornerstones of our Economy

Land

Labor

Capital

Information

Forging a Computer-Based Society:


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Jobs

From physical tomental

From muscle-power to

brain-power

Forging a Computer-Based Society:


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A Computer in Your Future

Where used? Bank withdrawal

Supermarket

Drive the car

Do I need a Personal Computer? Half of people have one at home

Many more use at work

Will I use a computer in my future career? Almost every job will involve use of a computer


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What is a computer?

A machine that can be programmed toaccept data (input), process it into

useful information (output), and store itaway (in secondary storage device) forsafekeeping or later reuse

Process is directed by software butperformed by the hardware


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Where Computers Are Used

Graphics

Graphs and charts

Animated graphics

Visual walk-through


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Retailing

Bar codes for pricingand inventory

Shipping


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Transportation

Cars

Run rapid transit systems

Load containerships

Track trailer cars/trucks

Monitor air traffic


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Government Forecast weather

Manage parks

Process immigrants

Social Security benefits

Taxes


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Training Airline pilots

Railroad

engineers

Paperwork Junk mail

Term paper

Record keeping


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The Computer System

Computer system consists of (see Figure

0.1):

central processing unit (CPU)

primary storage

secondary storage

input devices output devices

Communications devices.


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People

Computer programmer person who

writes programs

Users or End-users make use of the

computers capabilities


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Function of Computer System

Data handling

I Input

P Process

O OutputS Storage


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Figure 0.1: Hardware Component of

Computer Systems

CommunicationDevices

SecondaryStorage

- Magnetic disk

CentralProcessing Unit

(CPU)

Primary Storage

Input Devices- Keyboard

Output Devices- Printers

Buses


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Input devices

A computer hardware that allows a user toenter data and instructions

convert data and instructions intoelectronic form for input into the computer.

Getting data into the computer

Typing on a keyboard

Pointing with a mouse

Scanning with a scanner or bar-code reader


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Other Pointing Devices

What is atrackball?

Stationary pointing device

with a ball on its top or side

To move pointer, rotate ballwith thumb, fingers, or palm

of hand


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What are ajoystickand a

wheel? Joystickis vertical

lever mountedon a base

Wheelis

steering-wheel-type

input device Pedal simulates

car brakes and

accelerator


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What is alight pen?

Handheld input device

that can detect light

Press light pen againstscreen surface and then

press button on pen


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What is atouch screen?

Touch areas of screen with

finger Often used with kiosks


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Keyboard and Pointing Devices

What is astylus and a digital pen? Looks like a ballpoint pen, but uses pressure to writetext and draw lines

Used withgraphics tablets, flat electronic boards


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Voice Input How does voice recognition work?

Step 2. An analog-to-digital converter (ADC) translates

sound waves into digital measurements computer can

process. Measurements include pitch, volume, silences, and

phonemes. Phonemes are sound units such as aw andguh.

10010111010110101100001101

Step 3. Software compares

spoken measurements with those

in its database to find a match or

list of possible matches.

Matches

Step 4. To narrow a list down, software presents user with

a list of choices or uses a natural language component to

predict most likely match. User may correct any selection

made by software.

Natural Language Engine

Step 1. A user dictates text into a microphone.


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Voice InputWhat is aMIDI (musical instrument

digital interface)?

External device, such as electronic piano

keyboard, to input music and sound

effects


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Digital Cameras How does a digital camera work?

Step 1. Point to the image to

photograph and take picture.

Light passes into the lens of the

camera.

Step 2. Image is focused on a

chip called a charge-coupled

device (CCD).

Step 3. CCD generates an analog

signal that represents the image.

Step 4. Analog signal is converted

to digital signal by analog-to-

digital converter (ADC).

Step 5. Digital signal processor

(DSP) adjusts quality of image and

usually stores digital image on

miniature mobile storage media in

the camera.

Step 6. Images are transferred to a

computers hard disk by plugging oneend of the cable into a camera and the

other end into a computer; or images

are copied to hard disk from storage

media used in the camera.

Step 7. Using software

supplied with thecamera, images are

viewed on screen,

incorporated into

documents, edited, and

printed.


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Digital Cameras

What isresolution? Sharpness and clarity of image

The higher the resolution, the better the image

quality, but the more expensive the camera

Pixel(pictureelement)

is single point in

electronic image

Greater the number of

pixels, the better the

image quality


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Video Input

What isvideo input? Process of entering full-motion images

into computer

Video capture cardisadapter card that converts

analog video signal into

digital signal that

computer can use Digital video (DV)

camerarecords video as

digital signals


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Video Input

What are aPC video cameraand aWeb cam?

PC video cameraccDV camera used to capture video

and still images, and to makevideo telephone calls on Internet

Also called PC camera

Web camccvideo camera

whose output displays ona Web page


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Scanners and Reading Devices

What is ascanner?

Light-sensing device that

reads printed text and

graphics Used for image processing,

converting paper documents

into electronic images

Drum

Flatbed

Pen or

Handheld

Sheet-fed


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How does aflatbedscannerwork?

Step 2. Bright light moves underneath

scanned document.

Step 3. Image of the document is

reflected into a series of mirrors.

Step 1. Document to be scanned is

placed face down on the glass window.

Step 6. Users can print image,

e-mail it, include it in a document,

or place it on a Web page.

Step 4. Light is

converted to analog

electrical current that

is converted to

digital signal by an

analog-to-digital

converter (ADC).

Step 5. Digital information is sent to

memory in the computer to be used by

illustration, desktop publishing, orother software; or it is stored on disk.


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What is anoptical reader?

Optical characterrecognition(OCR)reads characters in

OCR font

Optical markrecognition

(OMR) reads hand-drawn pencil

marks, such as small circles

Device that uses light source to read characters, marks,

and codes and then converts them into digital data


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What is abar code reader? Uses laser beams to read bar codes


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What is amagnetic-ink character recognition(MICR) reader?


Can read text printed with magnetized ink

Banking industry almost exclusively uses MICR

for check processing


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Biometric Input

What isbiometrics?

Authenticates persons identity

by verifying personal

characteristic

Fingerprint scanner captures

curves and indentations of

fingerprint

Hand geometry system measuresshape and size of persons hand

Bi t i I t


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Biometric Input

What are examples of biometric technology? Voice verification system compares live

speech with stored voice pattern

Signature verification system recognizes

shape of signature

Iris recognition systemreads

patterns in blood vessels in back

of eye Biometric data is sometimes stored

on smart card, which stores

personal data on microprocessor

embedded in card


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Output devices

Monitor or screen Text

Numbers Symbols

Art

Photographs

Video

Printer

Black and white

Color

Convert from electronic form to some otherform

in a form that people can understand.

May display the processed results

Usable information


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What is Output? What isoutput?

p. 300 Fig. 6-1 Next

Data that has been processed into a useful form,

Output device is any hardware component that can convey

information to user

Displa De ices


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Display Devices What is adisplay

device?

p. 302

Output device that visually conveys information

Information on display device sometimes

called soft copy

Monitorhouses display device as separate

peripheral


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CRT Monitors What is aCRT monitor? Containscathode-ray

tube (CRT)

Screen coated with tinydots of phosphor material Each dot consists of a red,

blue, and green phosphor

Common sizes are 15, 17,19, 21, and 22 inches

Viewable size is diagonal

measurement of actual

viewing area

CRT Monitors


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CRT Monitors

How does video travel from the processor to a CRT

monitor?Step 1.The

processor sends

digital video data

to the video card.

Step 2.The video cardsdigital-to-analog converter

(DAC) converts the digital

Step 3.Theanalog signal is

sent through a

cable to the CRT

monitor.

Step 4.TheCRT monitor

separates the

analog signal

into red, green,and blue signals.

Step 5.Electron gunsfire the three color signals

to the front of the CRT.

Step 6.An image isdisplayed on the screen when

the electrons hit phosphor

dots on the back of the screen.

Video card(also called agraphics card)converts digital

output from computer into analog video signal


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Printers What is aprinter? Output device that

produces text and

graphics on paper

Result ishard copy, or

printout Two orientations:portrait

andlandscape

portrait

landscape

Speakers and Headsets


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Speakers and Headsets What is anaudio output device?

Computer component that produces music, speech, or

other sounds Speakers and headsets are common devices


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Speakers and Headsets What isvoice output? Computer talks to you through speakers on computer Internet telephonyallows you to have conversation

over Web


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The Processor

Central Processing Unit (CPU)

Converts data to useful information

The system unit

The brain of the computer

Interpret and execute instructions

Communicate with input, output and

storage


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Storage Devices

Components that stores and hold data,

instructions and information for future use.


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Two Types of Storage

Secondary storage

long-term storage

Primary storage or memory

temporary storage


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Memory / Primary Storage

Temporary storage

Holds input to be processed

Holds results of processing

Contains the programs to control thecomputer and manipulate input intooutput

Volatile


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Secondary Storage

Long-term storage

Non-volatile


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Secondary Storage Examples

Magnetic disks read and written bymagnetic disk drive Hard disk Diskette

Optical disks read and written by optical diskdrives CD-ROM DVD-ROM

Magnetic tape read and written by magnetictape drives Primarily used for back-up


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Communication Devices

Hardware components that enables a

computer to send and receive data,

instructions and information to or from oneor more computers

Connect home PC to other computers

Use modem to convert signals betweenelectronic (computer) and analog

(voice) formats


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Modem routers

module 1 - intro to computers and it

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