1. Introduction to Computers
Computer Components - Hardware
Lecture 2

2. Outline Computer Components Hardware Components
Central Processing Unit
Input Units
Output Units
Memory Unit
Storage Units

3. Computer Components Computers have two main components: Hardware
Physical components like screen and keyboard
Software
Set of instructions that tells the computer what to do and how to do it

4. Hardware Components Central Processing Unit Input Units Output Units
Memory Unit
Storage Units

5. Hardware Components Input Units Output Units Control Unit Storage Unit
ALU Unit

6. Hardware Components Input Units Output Units Control Unit Storage Unit
ALU Unit

7. Central Processing Unit (CPU)
Every PC system unit contains at least one chip called microprocessor (CPU) attached on motherboard.
The CPU follow the instructions to process the data to produce the information

8. Central Processing Unit (CPU)
Its is the brain of Computer.
It interprets and executes the instruction contained in software program.
It determines how fast your computer will run .
Its speed measured in MHz/GHz ( Megahertz or Gigahertz )

9. Central Processing Unit (CPU)
CPU Components
Control Unit(CU)
Arithmetic Logic Unit (ALU)
Registers

10. Central Processing Unit (CPU)
Control Unit (CU)
tells the rest of the computer system how to carry out the program’s instructions .
it moves the electronic signals (data) between :
Main memory and Arithmetic unit.
Main memory and Input/ output devices

11. Central Processing Unit (CPU)
Arithmetic and Logic Unit (ALU)
It performs mathematical and logical operations.
arithmetic (a= 5+4)
Logic (a > b)
Registers
Are immediate memory location used by the ALU to store the data in execution.

12. Hardware Components Input Units Output Units Control Unit Storage Unit
ALU Unit

13. Input Units
Input devices: are hardware used to translate data (words, sounds, images) into a form that the computer can process .

14. Input Units Input Units Input Units Keyboard Mouse Trackball Touch Pad
OMR
Microphone
Magnetic Strip
Light Pen
Input Units
Keyboard
Mouse
Trackball
Touch Pad
Scanner
Bar Code Reader
Joy Stick

15. Input Units
Keyboard
It is a board containing the keys of letters, numbers and some functions which allows you to type information into the computer.

16. Input Units The Mouse Trackball : it is a mouse turned upside down.
A small hand-held device used to point, select, click on items and to drag and drop items from one place to another.
Trackball : it is a mouse turned upside down.
The user rotate the ball with the fingers to move the cursor on the screen, and it saves the space which is taken up by the mouse

17. Input Units Light pen Touch pad
It is touch – sensitive device. We can move the cursor by move the finger on the pad surface (used in laptops).
Light pen
It is a light sensitive device, or pen-like device, connected to the computer by wire .

18. Input Units
Scanner
It allows you to scan pictures, text and images and save it to your computer in a digital form.
The Scanners can read the bar codes.
Scanner Types
Next slide

19. FlatBad
Sheet Fed
handHeld
Stationary Scanner
Drum Scanner

20. Input Units Bar Code Reader Joystick
It is a Photoelectric scanner that translates the bar code symbols into digital form.
Joystick
Small hand-lever that can be moved in any directions to control movement on the screen. It can be used for playing games

21. Input Units
Optical Mark Reader (OMR): is a device reads pencil marks on compatible scan form
Ex: Answer forms.
Magnetic Strip
A Thin Layer of magnetic material which is placed on credit cards and bank ATM cards and hotel room keys.

22. Input Units
Microphone : used o record the sound on the computer or input spoken text into the word
processor.

23. Input Units
Digital camera : the same as traditional camera but use the flash or disk to save images.
Video Camera: connected to the computer to be used in video conferencing or store movies.

24. Hardware Components Input Units Output Units Control Unit Storage Unit
ALU Unit

25. Output Units
Output devices: Devices used to translate the processed information into a form that humans can understand.

26. Output Units Output Units Speakers Projector Plotters Printers
Monitors

27. Output Units Types of monitors: 1- Cathode Ray Tube (CRT)
Monitors (Computer Screens )
It displays the text, information and pictures.
They are different in sizes, resolution and color.
Types of monitors:
1- Cathode Ray Tube (CRT)
2- Flat-Panel Display
Technologies include : liquid crystal display (LCD), plasma displays.

28. Output Units Printers Printer Type
-It is used to print the information or output of computers on papers.
Printer Type
1- Daisy wheel
characters are raised on the wheel , which strike the ribbon placed between them and the paper. (noisy and slow and produce carbon copies)
2-Dot matrix

29. Output Units 2-Dot matrix
use the pins to strike on an inked ribbon against paper. (inexpensive, produce carbon copies)
3-Inkjet
spray one or more colors of small droplets of ink at high speed onto paper. and its running cost is high.
(carbon copies can’t be produced).
(use one color or multiple colors)

30. Output Units 4-Laser printer
use a laser beam source to create a dot-like images on a drum. And these image treated magnetically charged ink-like toner and transferred from drum to paper.
(high quality, used for heavy use, expensive, can’t produce carbon copies)

31. Output Units (3-Plotters)
A special Printer use pen to draw on the paper under the computer control and the mapping software (used to draw maps).

32. Output Units Speaker/Head phones Projectors
They are used to output voice from a computer.
Projectors
Device that connect to computer to display output to large board

33. Input & Output Devices Touch Screen
A touch screen is an electronic visual display that can detect the presence and location of a touch within the display area.
It can be used as both Input and output device at the same time,
receives input from a finger or pin, and displays output on the screen.