UNIT 2 : The Computer System

2.3 Explain the concept of Input-Process-Output (IPO) Cycle.


The computer may seem like a very complicated machine, but it basically does three simple tasks: input, process and output. 

During the functioning of a computer. The first stage (things to work upon) is called input stage, the second stage (the actual work being performed) is called process stage and the third stage (the result) is called output stage. Certain input is needed to accomplish a task, a process is carried out on the input to obtain the output.

Every task follows this Input-Process-Output cycle (IPO cycle). A computer follows the I-P-O cycle that is, it needs certain input, carries out a process and produces the output.

Examples- Activity 1 : Buying Drinks from a Vending machine        
                   Input      : Inserting Coins, Pressing a button                 
                   Process  : Select a drink according the button pressed   
                   Output   : Drink, Coins changed 

                 Activity 2 : Using Computer   
                 Input      : Data and commands via input devices 
                Process   : The CPU works on the data according to the                                     input commands 
                Output    : The processed result on the output devices 

Firstly, Input means to put in or into and that is exactly what an input device does. An input device enables one to communicate with the computer. Input devices are used to enter information and issue commands. Examples of input devices are the keyboard, mouse, scanners, video cameras and microphones.

Then, information received from the input devices will then be processed in the Central Processing Unit (CPU). The CPU's job is to process instructions, perform calculations and manage the flow of information through a computer system. The CPU not only communicates with the input devices, but also the output and storage devices to perform tasks.

A storage device holds information. For the computer to receive instructions about what processing is to be done to the information, it must be held inside the computer long enough to be processed. A hard drive, tape drive, floppy disk, and CAROM drive are storage devices. The computer uses information stored on these devices to perform tasks.

Lastly, after the information has been processed, or the necessary tasks completed on the information, it will be outputted to you. The output device enables a computer to communicate with you. These devices display information on a screen, create printed copies or generate sound. Some of these devices are the monitor, printer and speakers.