Components of a computer system

Computer systems work on the same principle as an office clerk.  A basic computer system has five components :

Input-Process-Output-Storage (IPOS)

Input device Central processing unit (CPU) Main memory Backing store Output device

The below  figure illustrates how each of these five units relates to the others. The arrows indicate the flow of processing. 

		Central Processing unit　 The central processing unit (CPU) is the heart of the computer system. All processing is carried out by the CPU.
Input device Data are input through the input device. The function of the input device is to put the data into a form that is acceptable to the computer.		Main memory The computer system needs stored programs and data to carry out the processing. These are stored in the main memory.		Output device The results are output by the output device in a form that can be understood by humans.
		Backing store As the main memory is of limited space, some data and programs are stored in the backing store

Before data processing takes place, program instructions and data must be entered into the computer. For this, we need input devices.

Once the data have been processed, they must be presented in a form that we can understand. For this, we need output devices.

These input and output devices are known as peripheral devices. The word peripheral means on the outside of. A peripheral device is a device on the outside of the central processing unit. It is controlled by the CPU.

Storage is needed as the output will disappear when you turn off the computer. In order to use the output again in the computer system or another computer system, it is better to store it in a computer readable form. So we need a relatively more permanent storage. 

[ Home ] [ Components of a computer system ] [ Software and hardware ] [ Introduction of CPU ] [ Main Memory and Backing Store ] [ OS ] [ Applications software ] [ Computer_communication ] [ Chinese Input ] [ Useful links ] [ Quiz Zone ] [ Syllabus on Computer System ] [ News on technology and computer ]  

You are the visitors !　

Thank you ! Last updated: 2001/10/26 This homepage was designed by 7B Lau Ming Wai (13) Copyright @ 2001CA. All right reserved.