Page 9 - ICT_for_JHS_Classical

Chapter 1 - Introduction to Computers

In this chapter we’ll take a good hard look at computers and their classifications,

categories, types and characteristics. Best of all, we’ll describe all computers in
detail, so you will be able to identify them. Finally, we look at factors that affect
computer performance and the importance of computers.

That’s a lot of material to cover, so let’s get started!

What is a Computer?

A computer is a device that accepts data and manipulates it into information
based on a program or sequence of instructions on how the data is to be
processed. It an electronic device that uses a program to process data into
information.

Classification of Computers

Generations
Types

Purpose (function)
Capacity (size)

Classification by Generations

Generation in computer terminology is a term used to distinguish between
varying hardware and software technologies which make up an entire computer
system.

First Generation (1946-1959)
The computers of first generation used Vacuum Tubes as circuitry for CPU

(Central Processing Unit). These computers were too large. They produced a
lot of heat. They also used a lot of electricity and were very expensive to acquire
too. An example is the mainframe.

Second Generation (1959-1965)
In this generation transistors were used. These made the computers cheaper,
consumed less power, more compact in size, more reliable and faster than the
first generation.