1. Computer Skills Preparatory Year 2011-2012 Presented by:
L.Obead Alhadreti

2. < the death of Steve Jobs! >
Last week - Lecture 1
The definition of the computer
The history of computers
The types of computers
< the death of Steve Jobs! >

3. Lecture 2 - Outline The main parts of the Personal Computer
Computer Hardware
Memory Measurement
Factors that Impact on a Computer's Performance

4. Main parts of the PC Hardware: Software Computers Have Two Main Parts:
The term hardware refers to the physical components
of your computer which you can physically touch or see
such as your monitor, case, disk drives, microprocessor and
other physical parts.
Software
The software is the instructions that makes the computer work.
Software is held either on your computers hard disk, CD-ROM,
DVD or on a floppy disk and is loaded from the disk into
the computers RAM, as and when required.

5. Main parts of the PC

6. Main parts of the PC

7. Main parts of the PC

8. Main parts of the PC Hardware:
Hardware can be categorised into: Input Units, Output Units Central processing Unit, Memory Unit (main memory), and Storage devices (secondary memory).

9. Main parts of the PC Input Units:
Input units: those parts of the compute receiving
data to programs.
The Mouse
A small hand-held device which has the shape of mouse.
enhances user’s ability to input commands, manipulate text,
images.

10. Main parts of the PC The Keyboard
The keyboard is still the commonest way of entering
information into a computer.
Tracker Balls
an alternative to the traditional mouse and often used by
graphic designers
Scanners
A scanner allows you to scan printed material and
convert it into a file format that may be used within
the PC.

11. Main parts of the PC Touch Pads
A device that lays on the desktop and responds to
pressure.
Light Pens
Used to allow users to point to areas on a screen.
Joysticks
Many games require a joystick for the proper playing of
the game.

12. Main parts of the PC Output Units:
Output Units: those parts of the computer that provide
results of computation to the person using the
computer.
Monitors:
are the most commonly used output device. used for
outputting information in an understandable format for
humans.

13. Main parts of the PC Printers
There are many different types of printers: dot matrix,
ink jet, and Laser. In large organizations laser printers
are most commonly used due to the fact that they can
print very fast and give a very high quality output
Plotters
A plotter is an output device similar to a printer, but
normally allows you to print larger images.

14. Main parts of the PC Speakers
Enhances the value of educational and presentation products.

15. Main parts of the PC Central Processing Unit:
the Central Processing Unit (CPU), also called a processor, or a microprocessor, is the brains within your computer. It performs the arithmetic and logical process within the computer.
made up from a semiconductor, Silicon.
 contain hundreds of millions of transistors which are
interconnected through extremely fine wires made of copper.
it determines how fast your computer will run.
The speed (clock speed) of CPU measured by Hertz (MHz) and (GHz).
measured by its Hertz speed (e.g. MHz, GHz). A processor with speed of 600 MHz is much faster than a processor with speed of 400 MHz.
processor manufacturers: Intel, AMD, and Cyrix processor. 
CPU types: Intel Pentium, Intel Celeron, and AMD Athlon.

16. Main parts of the PC The CPU consists of :
Control Unit (CU): coordinates all activities of the computer by determining which operations to perform and in what order to carry them out.
Arithmetic and Logical Unit (ALU): perform arithmetic operations (addition, subtraction, multiplication and division), and Logical operations (and, or, not, …) and to make some comparisons (less-than, equal, … etc.)
Some Registers: where the data used by ALU are stored.
enjoy watching:

17. Main parts of the PC Memory Unit: RAM:
The RAM (Random Access Memory) is where the operating system is
loaded and also where your applications, such as word processor, are
copied. It saves the computer data temporarily while the program is
running. It loses its contents if power is disconnected (volatile memory).
ROM:
The ROM (Read Only Memory)is a special chip held
on your computer's system (mother) board.
It contains software that is required to make your
computer work with your operating system. It does not lose
its contents by disconnection of power.

18. Memory Measurement Bit
All computers work on a binary numbering system, i.e. they process data in one's or zero's. This 1 or 0 level of storage is called a bit.
Byte
A byte consists of eight bits.
Kilobyte
A kilobyte (KB) consists of 1024 bytes.
Megabyte
A megabyte (MB) consists of 1024 kilobytes.
Gigabyte
A gigabyte (GB) consists of 1024 megabytes.

19. Main parts of the PC Storage Devices: The internal Hard Disks:
Internal hard disk are the main, large data storage area within your
computer. used to store your operating system, your application
programs (i.e. your word processor, games etc) and your data. They are
much faster than CD-ROMs and floppy disks and can also hold much
more data.
The speed of a hard disk is often quoted as "average access
time" speed, measured in milliseconds. The smaller this
number the faster the disk.
Often in excess of 10 Gigabytes.

20. Main parts of the PC The external Hard Disks:
Normally slower that internal disks, but more expensive versions offer
the same performance as internal hard disks.
Capacity: same as internal disks.
Cost: More expensive than internal disks.

21. Main parts of the PC Floppy Disk: They are very slow compared to
hard disks or CD-ROMs, and hold relatively small
amounts of data (1.44 Mbytes). Unreliable.
Zip Disk: Slower than normal hard disks but ideal for backups.
Capacity: 100 or 250 Megabytes.

22. Main parts of the PC
Jaz Disk: Slower than normal hard disks but ideal
for backups. Capacity: around 2 Gigabytes.
CD-ROM (Compact Disc Read-only memory)
& DVDs (Digital Versatile Disc): Similar to the audio devices
familiar in home use but hold computer data rather
than music. The storage capacity of CD reaches 750
megabyte, whereas the storage capacity of the DVD
reaches more than 4 gigabytes.

23. Main parts of the PC
Peripheral devices: A peripheral device is any device that you can
attach to your computer.

24. Factors That Impact on a Computer's Performance
CPU speed
RAM size
Hard disk speed and capacity

25. Components of a Computer System
Central Processing Unit (CPU)
Data
control unit (CU)
Memory
Arithmetic
logic
Unit (ALU)
output
units
RAM
Input
units
ROM
secondary
Memory
Information/
Knowledge

26. Lecture 2 - Conclusion The main parts of the Personal Computer
Hardware
Memory Measurement
Factors That Impact on a Computer's Performance

27. Lecture 3- Next Week !
Computer Software