Download File - Computer Information Technology

Introduction to Computers
What is a computer?
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An electronic device, operating under the
control of instructions stored in its own
memory unit, that can accept data,
manipulate the data according to specified
rules, produce information from the
processing, and store the results for future
use.
Devices that comprise a personal
computer.
Inside a computer
Information Processing Cycle—four
general operations
Input
 Processing
 Output
 Storage
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Input Devices
Keyboard
 Mouse
 Digital camera
 Scanner
 Microphone
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What are the components of the
computer?
Input devices
 Central processing unit (CPU)
 Output devices
 Memory
 Storage devices
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Keyboards
Mouse Devices
Digital Cameras
Scanners
Microphones
Central Processing Unit
Made up of the control unit and
arithmetic/logic unit
 The brains of the CPU is the processor.
There are different brands and speeds

Pentium made by Intel
 Celeron made by Intel
 Athlon made by AMD
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Memory
RAM—also called Random Access Memory
 ROM- also called Read Only Memory
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Processors & Memory
Role of the CPU
 Role:
The CPU also called microprocessor, or brain of
the computer, contains millions of switches and
pathways to help the computer make decisions. The
switches control the flow of electricity as it travels
across the pathways. Computer programs are
special instructions written to tell the computer
which switches to turn on or off.
 Speed: deciding factor on which computer to
purchase. The system clock is an electronic pulse
used to synchronize the processing and determines
the speed of the processor, measured in megahertz.
The higher MHz the faster the computer.
Data Representation
Byte—one character of data
 Kilobyte—one thousand bytes of data
 Megabyte—one million bytes
 Gigabyte—one billion bytes
 Terabyte—one trillion bytes
 Petabyte—one quadrillion bytes
 Exabyte—one quintillion bytes
 Zettabyte—one sextillion bytes
 Yottabyte—one septillion bytes
http://www.jimloy.com/math/billion.htm
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Output Devices

Printers

Impact printers
 Dot

matrix printers
Nonimpact printers
 Ink
jet
 Laser
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Color
B&W
Monitors
CRT’S
 LCD’S
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STORAGE DEVICES

Floppy Disks

3.5-inch disks store 1.44M of data

Must be formatted
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Hard Disks
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Available as DVD-ROM, DVD-R, DVD-RW
Can hold 4.7 GB of data
Zip Drives—high capacity floppy disk drive; has lost popularity
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Available in a variety of formats—CD-ROM, CD-R, CD-RW
A typical CD holds about 650 MB of data
DVD’s

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Spins at 5,400 – 7,200 rpm (revolutions per minute)
Can store anywhere between 10G – 250G+ of data
CD’s—Compact Discs

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Tracks
sectors
Zip disks can hold from 100 MB – 250 MB of data
USB Flash Drive

Storage capacity between 32 MB – 4 GB
STORAGE DEVICES
Software—Can be categorized into
four types
System software
 Application software
 Educational software
 Entertainment software

System Software

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Controls the operations of computer equipment
Operating System software tells the computer how
to:
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OS is loaded into memory when the computer is
turned on

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Load
Store
Execute
This process is called booting
Most OS’s use a Graphical User Interface (GUI)


Provides visual cues such as icons
Each icon represents an application
Application Software
Programs that tell a computer how to
produce information
 Commonly used applications

Word processing
 Spreadsheet
 Database
 Presentation
 Financial
 Email
 Taxing

Educational Software
Software that can be used for learning
purposes
 Examples include:

Jump Start Series
 Mavis Beacon Teaches Typing
 Reader Rabbit
 Encarta or World Book
 Math Blaster
 Rosetta Stone Spanish
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Entertainment Software
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Sports games
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Madden NFL
MLB
The Sims
World of Warcraft
Rollercoaster Tycoon
Final Fantasy
Halo
Myst
Half Life
Barbie Fashion Show
Types of Computers
Type
Size
Power
Purpose
Supercomputers
Largest
Fastest processing
speeds compared to
other computers
•Cost can be several million
dollars
•For corporations with lots
of data to be processed
Mainframe computers
Large
Less powerful than
supercomputers but
large compared to
personal computers
•Can cost hundreds of
thousands of dollars
•Performs centralized
processing tasks for many
users
Minicomputers
Larger than
microcomputers
but smaller than
mainframe
computers
Same as
microcomputers
•Used for companies with
many users and large
amounts of data and can
run on any computer
hardware
Microcomputers and
notebook computers
Fits on a desktop
Not meant for large
amount of data
•Writing papers, tracking
finances, playing games,
connecting to the Internet.
PDA’s, Cell phones, calculators, interactive books, digital cameras, game systems are accepted as
they make everyday tasks easier to accomplish.
Binary number system
Computers only understand machine language, or binary,
which is ones and zeros.
 Through the pathways and by turning switches on and off
the CPU processes ones and zeros
 When electricity is present it represents a one. The absence
of electricity represents a zero.
 Coding Systems such as American Standard Code for
Information Interchange (ASCII) determines which
combination of zeros and ones represents the letter A or
the number 1.
 Each one or zero is a bit, and eight bits or combinations of
ones and zeros represents a byte.

Networking
A network connects one computer to other
computers and peripheral devices
 Allows computers to share:

Data – special group projects, databases, etc.
 Hardware – printers or scanners
 Software – instead of purchasing programs for
each individual computer, a site license can be
purchased for the number of users and it is less
expensive
 Files – collaborative, allows users to work
together
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