Transcript Computer Components

Module 1
IT
Concepts of information technology
Part 1
Types of
Computers

Mainframe Computers
 PC ( Personal Computer )
 Networked Computer
 Laptop
 PDA ( Personal Digital Assistant )
Mainframe computer

Description
Are big , powerful , expensive computers used by most large organization

Capacity :
very power full computers
 Speed
Very Fast in processing data
 Costs :
very expensive
 Users
Large companies including banks...
( PC) Personal computer

Description
IBM invented the pc since 1981

Capacity :
large hard disk
 Speed
Fast normally measured in GHz
 Costs :
Getting cheaper by day
 Users
Home users , Doctors , Education …..
Networked Computer

Description
Allow you to connect two or more than one computer together

Capacity :
large hard disk
 Speed
Fast normally measured in GHz
 Costs :
A pc need inexpensive card to connect to network
 Users
Home users , Doctors , Education , any one…..
Laptop

Description
Small , Portable , Can run on batteries as well as main power

Capacity :
Large hard disk, often less powerful than PC which is equivalent in price

Speed
Fast normally measured in GHz – Speed specification are less than PC
which is equivalent in price

Costs :
Exceeds when compared with PC
 Users
Business users , People on the move , Educational user
PDA ( Personal Digital Assistant )

Description
Use a special pen rather than keyboard, can store and retrieve information

Capacity :
Much smaller than PC

Speed
Much slower than PC

Costs :
Exceeds when compared to PC
 Users :
Mostly Business Users
Hardware
Computer
Components
System Unit

The name given to Main PC box
It Houses items like ….
• Mother Board
• CPU
• RAM
• CD
• Floppy Disk
System (Mother ) Board

All items of the
system unit attached
to Mother board ,
either directly or via
cable
CPU (Central Processing Unit )


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
IT is one of the most important components within
Computer
It is the brain within your Computer
It performs most of the calculation within the
computer
It determines How fast you Computer will run
It is measured by GHz
 2 GHz Pentium is much faster than 1GHz Pentium
Memory
RAM ( Random Access Memory )
•It’s where the operating system is
loaded when you switch on your
computer
•It’s where your application are copied
to when you start application (such as
word processing )
•Volatile and changeable
•The more RAM you Have installed in
you Computer is better
•It is measured by MB
•These days you will commonly find
over 512 MB of Ram installed
ROM - BIOS
( Read only Memory – Basic input out put system )



It is special chip held on your
computers’ mother board
It contains Software which
makes your computer work
with your operating system
It is Non volatile,
unchangeable
Serial Port

It is socket located
at the back of your
computer which
enable you to
connect items to the
computer , such as
Modem
Parallel Port

It is socket located at
the back of your
computer which
enable you to
connect items to the
computer , such as
Modem
USB (Universal Serial Bus )

It is Relatively new
item within the PC
 You will see one or
more USB Sockets at
the back of Your
computer
 It enables you to Plug
in devices such as
Printer, Scanner,
Digital camera .
Input And Output
Device
Input Device ….
Input device allow you to input Data to the
computer

Key board
 Mouse
 Tracks ball
 Touch pad
 Light pen
 Joy stick

Scanner
 Web Cam
 Digital Camera
Key Board

Key board is the
commonest way
of entering data
to the computer
Mouse

The mouse came into
common use on PC
with the introduction
of Microsoft operating
system (Windows) .
 Before this (DOS)
operating system had
been controlled via
the keyboard
Tracker ball

A tracker ball is an
alternative to the
mouse.
 A tracker ball is
favorite by graphic
designers.
Touch pad

Touch pad can be
used by graphic
artists
Light pen

A light pen is used
to allow users to
point to areas on
screen and its often
used to select menu
Joy stick

Used in games
Scanner

A scanner allows you
to scan printed
material and convert
it into a file format
which may be used
within PC
Web Cam


Ever since it was
invented , the web
has become
increasingly
interactive .
It allows you to
communicate in two
ways not just text
communication but
also sound and video
Digital Camera

A digital camera can be
used in the same way of
traditional camera but
instead of storing images
on rolls of films , the
images are storing in
memory housed within
the camera ,this images
can easily be transferred
to your computer
Output Device ….
Output devices allow you to output
information From the computer

Computer monitor
 Flat screen monitor
 Computer presentation projection device
 Printers
 speakers
Computer monitor

The VDU ( Visual
Display Unit ) is the
computer screen
used to output
information.
Flat screen monitor

Flat screen
computer monitor
have become
available , these
take less size on
the desk and use
less energy than
the traditional
Computer presentation
projection device

It can be attached to
your computer and it
is useful to display
presentations to
group of people.
Printers

Laser Printer
 Color laser printer
 Inkjet printers
 Dot matrix printers
 Plotter
Speakers
Output / Input Device ….
Some devices are both input / output devices

Touch screen
Storage Device
Hard desk ( Internal – External )
 Zip Driver
 Diskette
 CD desk
 DVD driver
 Jaz Disks
 Back up tape
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Hard disk

Internal Hard Disks

Speed:
–
–
Very fast!
The speed of a hard disk is often measured by “RPM" speed,
The smaller this number the slower the hard disk.
Capacity:
– Enormous! Often in excess of 10 Gigabytes. A Gigabyte is
equivalent to 1024 Megabytes.

Cost:
Getting cheaper by the day
Hard Disks
External Hard Disks

Speed:
– Normally slower than internal disks, but more
expensive, offer the same performance as internal hard
disks.

Capacity:
– Same as internal disks.

Cost:
– More expensive than internal disks.
DVD Drives

Speed:
– Much faster than CD-ROM drives but
not as fast as hard disks.

Capacity:
– Up to 30 G bytes.

Cost:
– Slightly higher than CD-ROM drives.
CD-ROM
(Compact Disc)

Speed:
– Much slower than hard
disks.

Capacity:
– Around 650 Mbytes.
Zip Disks

Speed:
– Slower than hard disks but ideal for backup.

Capacity:
– 100 or 250 Megabytes.
Jaz Disks
Speed:
– Slower than hard disks
but ideal for backup.

Capacity:
– Around 2 Gigabytes
(2048 Megabytes).
Diskettes (Floppy Disks)
It can be write protected to prevent data from
changes or infection of viruses.
 Speed:
– Very slow!

Capacity:
– Normally 1.44 Mbytes.

Cost:
– Very cheap.
Back up Tape

Used to archiving
the files that are
not needed
Storage measurement

Tera byte = 1024 Giga byte
 Giga byte = 1024 Mega byte
 Mega byte = 1024 Kilo byte
 Kilo byte =1024 Byte
 Byte = 8 Bit
Software
Types of Software
Operating
System
Application Program
Format


Unformatted disk need operating system data written to them
before they can store files.
Pre formatted disk can be used immediately to store
data.
 Full formatting completely erase the previous contents
of a disk.
 You can purchase preformatted disk.
 You can reformat a used floppy disk.
Operating System

The operating system is a special type of
programs which is loaded automatically
when you start your computer

There are number of different types of
operating system
 DOS
 Windows

Unix and Linux
 Mac/OS
DOS

IBM invented Pc Since 1981 And used
DOS Operating system.
 This operating system was very basic.
 You had to be computer expert just to
understand how to use computer
 It was not user – friendly
Windows

Microsoft introduced windows which is more
powerful than DOS and which is commonly used
on PC today.

There are numbers of different types of windows

The main advantage of windows that it has a
Graphical User Interface ( GUI )
Graphical User Interface ( GUI )
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It is part of operating system which display windows and
drop down menus
The system using windows, icons to operate a computer
It enables you to drive your computer by using mouse
Advantage
All programs look similar and when switches from a
program supplied by one manufacturer to different
program supplied by another manufacturer , you will find
the transition very easy
By GUI its easier to learn and use Application Program
Unix & Linux
 Are
other examples of Operating
Systems which may be run on PCs
Other Types
of computers ,
Such as Manufactured by Apple
have a completely different
operating System called
Mac/OS .
Application Software

An application program is the type of
program which you use when the operating
system has been loaded.
 Can run more than one at the same time.
 Can be used to edit data type
Example ….

Word Processor
Create letters, Faxes, Memos
Spread
Sheet ( Excel )
Make financial projects
With Charts
Database
( Access )
Sort large amount of information
Presentation (
Power point )
Crate overhead projection or slides
•Desktop publish
•Accounts payroll ( Sage )
Producing a newspaper with
(Make financial projects )
complex page layout
large Organizations
Things to avoid
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Dust
Drinking and eating over the key board
Heat
Moisture
Don’t move the system while it switched on
Follow the correct steps to shutdown your computer
Don’t place object in the top of monitor
Don’t place floppy disk near monitor . Monitor produce a
strong electromagnetic
System Cycle

Most project work in cycle
 First step ( System analysis):
Analyze the need of computer user.

Second Step ( Design )
Draw up the plans on how it can be implemented on a real.

Third Step ( Programming )
Convert the design to actual plan.

Final Step ( Testing )
Testing the software.