1. General Purpose Computer

When you hear the term 'General Purpose Computer' in an exam question do not think of a standard PC or laptop sitting on your desk - it is more basic than that!

A 'General Purpose Computer' is a machine that is capable of carrying out some general data processing under program control.

There are computers designed specifically for one special task - that computer will carry out its job with extreme speed - but that is all it can do. For example in laboratories around the world there are computers that can take in a vast amount of test data and analyse it very quickly with the help of specially designed hardware. But you would not normally run a word processing application on such specialised (expensive) machines!

A 'General Purpose Computer' is able to carry out a wide range of tasks.

This web site explains what are the most basic parts of this machine.

First of all, there are three parts to it as shown in the diagram below:

 

There is a device inside the general purpose computer that is called the 'Central Processing Unit or CPU as it is commonly called. It almost always contains the 'Control Unit' and the Arithmetic Logic Unit parts of the system. (Note: To be technically correct it also contains some RAM but for the purposes of this lesson, you should consider most of the RAM to be off the CPU).