1. Lesson 1 The Computer Mohamed Zaki Principal Lecturer
Computer Systems / Ch. 1

2. Main Topics What is a Computer? Computer system. Peripherals Units
Input Peripherals.
Output Peripherals.
Storage.
Units
Operating systems
Applications
Computer Networks
Computer Systems / Ch. 1

3. What is a Computer?
Computer: is a programmable machine that receives input, stores and manipulates data/information, and provides output in a useful format.
Computer Systems / Ch. 1

4. General Purpose Computer
General-Purpose computer used in many applications, such as (document typing, Drawing, communication, games,..etc)
Computer Systems / Ch. 1

5. Computer Components As a System
Computer System
Hardware
Software
Peripherals
Central
Processing
Operating
System
Application
Programs
Control Unit
ALU
Main Memory
Input Unit
Output Unit
Secondary
Storage
MS-Windows
MS-Word
MS-Excel
MS-Power Point
MS- Access
Computer Systems / Ch. 1

6. 1-Computer Hardware
Hardware devices can be organized according to the following system functions:
Input: Devices that convert data into electronic form in the computer system.
Output: The output devices are used to convert the electronic information into a human understandable form.
Processing:  The CPU is the main processing component. ALU (Arithmetic Logic Unit) will perform all the processing.
Storage: Takes place in the primary storage unit of the CPU and in secondary storage units. these devices store data and program instructions are needed for processing.
Control: control unit of the CPU is the control component of the computer system. It interprets computer program instructions and transmits directions to other components of the computer system.
Computer Systems / Ch. 1

7. Peripherals Parts of computer that transfer data in and out.
Input Peripherals.
Output Peripherals.
Secondary Storage.
Computer Systems / Ch. 1

8. Input Peripherals: Devices used for transferring data from the outside world representation into the internal character code of the computer.
Keyboard.
Barcode reader: Barcode data can be described as a sequence of vertical lines vary in thickness, light focuses on and scanned across these lines using a small laser beam, then data can be read and input to computer.
Computer Systems / Ch. 1

9. Other input peripherals:
Light pens }
Mice }
Touch screens. }
Digitizers.
Scanners.
Microphones.
Cameras.
Computer Systems / Ch. 1

10. Secondary Storage Hard disks Optical Storage Flash Memory
- CD (Compact Disc)
- DVD (Digital Versatile Disc)
Flash Memory
Computer Systems / Ch. 1

11. Storage Units
Bit (Binary Digit): it is the smallest unit to store data,(0 or 1).
Byte (B) :it is the basic storage unit of memory. It consists basically of 8 bits.
It can hold one symbol only at a time such as “A”, “a” , “$” and so on. Symbols are converted into binary codes
Kilo Byte (KB)=1024 B
=210 B
Computer Systems / Ch. 1

12. Storage Units of Memory
Mega Byte (MB)=1024 KB
=(1024 x 1024) B =104,8576 B
= More than a Million of bytes.
=210 x 210=220 B.
Giga Byte (GB)=1024 MB
=(1024 x 1024) KB
=(1024 x 1024 x1024) B
=104,8576 KB = 1,073,741,824 B
= More than a Billion of bytes.
=210 x 210 x 210 = 230 B.
Computer Systems / Ch. 1

13. Storage Units * % TByte 1024 GByte 1024 MByte 1024 KByte 1024 Byte 8
Bit %

14. Operating System
An operating system, or "OS," is software that communicates with the hardware and allows other programs to run and manage them.
Every desktop computer, tablet, and smartphone includes an operating system that provides basic functionality for the device
Computer Systems / Ch. 1

15. Application Programs They are used to do one task such as:
MS – Word: allows you to produce letters, memos etc.
Antivirus: Is a software program that is used to detect and remove viruses from your computer
Skype: is used for communications
Chrome: is used for web browsing
Computer Systems / Ch. 1

16. Computer and Network
A network is defined as two or more computers linked together for the purpose of communicating and sharing information and resources.
Computer Systems / Ch. 1

17. Types of Network Based on the size and functions:
Local Area Network. (LAN)
Used over small area.
Number of computers is usually limited
Thursday, September 20, 2018Thursday, September 20, 2018

18. Types of Network Wide Area Network (WAN).
It has no geographical Limitations.
Number of computers is not limited.
Thursday, September 20, 2018Thursday, September 20, 2018

19. File Types in MS-Office
Computer Systems / Ch. 1

20. Other File Types Type Extension Normal text .txt images
.Jpg, .pmp, .gif
Applications
.exe
Web pages
.htm, .html
Computer Systems / Ch. 1

21. MS-Office Shortcuts
Computer Systems / Ch. 1

22. Refreshing Questions 10 MB =_____ KB.
Which program allows you to produce letters, memos etc.
Database Application
Photo editing
Web browsing
Word processing
Computer Systems / Ch. 1

23. Refreshing Questions Which one of the following used as input device?
Printer
Monitor
Scanner
Plotter
Computer Systems / Ch. 1

24. Refreshing Questions
List main four types of Hardware, and give one example for each.
Computer Systems / Ch. 1