The Computer Computer Systems / Ch. 11 Mohamed Zaki Principal Lecturer

Main Topics What is a Computer? Computer system. Peripherals – Input Peripherals. – Output Peripherals. – Storage. Units Computer Systems / Ch. 12

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. 13

General Purpose Computer 1.General-Purpose computer used in many applications, such as (document typing, Drawing, communication, games,..etc) Computer Systems / Ch. 14

Computer Components As a System Computer Systems / Ch. 15 Computer System Hardware Software Peripherals Central Processing Central Processing System Programs System Programs Application Programs Application Programs Control Unit ALU Main Memory Input Unit Output Unit Secondary Storage MS-Word MS-Excel MS-Power Point MS- Access MS-Windows

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. 16

Peripherals Parts of computer that transfer data in and out. Input Peripherals. Output Peripherals. Secondary Storage. Computer Systems / Ch. 17

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. 18

Other input peripherals: Light pens. } Mice } Touch screens. } Digitizers. Scanners. Microphones. Cameras. Computer Systems / Ch. 19

Secondary Storage Hard disks Optical Storage - CD (Compact Disc) - DVD (Digital Versatile Disc) Flash Memory Computer Systems / Ch. 110

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 =2 10 B Computer Systems / Ch. 111

Storage Units of Memory 4.Mega Byte (MB)=1024 KB =(1024 x 1024) B =104,8576 B = More than a Million of bytes. =2 10 x 2 10 =2 20 B. 5.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. =2 10 x 2 10 x 2 10 = 2 30 B. Computer Systems / Ch. 112

Storage Units % Bit Byte KByte GByte MByte TByte *

Refreshing Questions 10 MB =_____ KB. Computer Systems / Ch. 114 Which program allows you to produce letters, memos etc. A.Database Application B.Photo editing C.Web browsing D.Word processing

Refreshing Questions Computer Systems / Ch. 115 Which one of the following used as input device? a)Printer b)Monitor c)Scanner d)Plotter

Refreshing Questions List main four types of Hardware, and give one example for each. Computer Systems / Ch. 116