1. Concepts of information technology
Module 1 IT
Concepts of information technology

2. Part 1

3. Types of Computers Mainframe Computers PC ( Personal Computer )
Networked Computer
Laptop
PDA ( Personal Digital Assistant )

4. Mainframe computer Description Capacity : very power full computers
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...

5. ( 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 …..

6. Networked Computer Description Capacity : large hard disk Speed
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…..

7. Laptop Description Capacity : Speed Costs :
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

8. 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

9. Hardware

10. Computer Components

11. System Unit The name given to Main PC box It Houses items like ….
Mother Board
CPU
RAM CD
Floppy Disk

12. System (Mother ) Board
All items of the system unit attached to Mother board , either directly or via cable

13. CPU (Central Processing Unit )
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

14. Memory

15. 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

16. 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

17. Serial Port
It is socket located at the back of your computer which enable you to connect items to the computer , such as Modem

18. Parallel Port
It is socket located at the back of your computer which enable you to connect items to the computer , such as Modem

19. 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 .

20. Input And Output Device

21. 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

22. Key Board
Key board is the commonest way of entering data to the computer

23. 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

24. Tracker ball A tracker ball is an alternative to the mouse.
A tracker ball is favorite by graphic designers.

25. Touch pad
Touch pad can be used by graphic artists

26. Light pen
A light pen is used to allow users to point to areas on screen and its often used to select menu

27. Joy stick
Used in games

28. Scanner
A scanner allows you to scan printed material and convert it into a file format which may be used within PC

29. 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

30. 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

31. Output Device ….
Output devices allow you to output information From the computer
Computer monitor
Flat screen monitor
Computer presentation projection device
Printers
speakers

32. Computer monitor
The VDU ( Visual Display Unit ) is the computer screen used to output information.

33. Flat screen monitor
Flat screen computer monitor have become available , these take less size on the desk and use less energy than the traditional

34. Computer presentation projection device
It can be attached to your computer and it is useful to display presentations to group of people.

35. Printers Laser Printer Color laser printer Inkjet printers
Dot matrix printers
Plotter

36. Speakers

37. Output / Input Device …. Some devices are both input / output devices
Touch screen

38. Storage Device Hard desk ( Internal – External ) Zip Driver Diskette
CD desk
DVD driver
Jaz Disks
Back up tape

39. Hard disk Internal Hard Disks Speed: Cost: 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

40. Hard Disks External Hard Disks Speed: Capacity: Cost:
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.

41. DVD Drives Speed: Capacity: Cost:
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.

42. CD-ROM (Compact Disc) Speed: Capacity: Much slower than hard disks.
Around 650 Mbytes.

43. Zip Disks Speed: Capacity:
Slower than hard disks but ideal for backup.
Capacity:
100 or 250 Megabytes.

44. Jaz Disks Speed: Capacity:
Slower than hard disks but ideal for backup.
Capacity:
Around 2 Gigabytes (2048 Megabytes).

45. 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.

46. Back up Tape
Used to archiving the files that are not needed

47. Storage measurement Tera byte = 1024 Giga byte
Giga byte = 1024 Mega byte
Mega byte = 1024 Kilo byte
Kilo byte =1024 Byte
Byte = 8 Bit

48. Software
Types of Software
Operating System
Application Program

49. Format Pre formatted disk can be used immediately to store data.
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.

50. Operating System DOS Windows
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

51. 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

52. 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 )

53. Graphical User Interface ( GUI )
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

54. Unix & Linux
Are other examples of Operating Systems which may be run on PCs

55. Other Types of computers , Such as Manufactured by Apple have a completely different operating System called Mac/OS .

56. 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

57. Create letters, Faxes, Memos
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
Producing a newspaper with
complex page layout
Accounts payroll ( Sage )
(Make financial projects )
large Organizations

58. Things to avoid 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

59. 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.