Introducing the Computer

Abstract

Mastering computers calls for an understanding of computers as machines in the service of man, and how they have come to be the characteristic machines of our age to such an extent that this part of the twentieth century is often called ‘The Computer Age’. The popular image of a computer as an electronic brain, or the professional jargon which attributes ‘intelligence’ and ‘memory’ to computers, serves only to confuse a proper understanding of computers as machines designed and built by people, for use by people. Although it is not easy to describe a computer in a few words, in principle the computer is a simple machine, or rather a group or system of simple machines, co-ordinated by a novel form of automatic control. Its full name is the electronic digital computer:

• electronic because it consists of electronic components: transistors, capacitors, resistors and now of course the ubiquitous integrated circuit or microchip. These components are activated by electrical impulses;

• digital because these electronic components are designed to represent and perform operations on digital as opposed to analog signals. The best way to explain the difference between the words analog and digital is to consider the two types of clocks and watches now currently available. They both measure time, but the digital watch divides time up into a series of separate or ‘discrete’ packets: seconds or some fraction of a second. The analog watch, on the other hand, exactly copies the ‘flow’ of time (like an ‘ever-rolling stream’) by the continuous movement of hands over a dial;

• computer because originally (but not necessarily now) these operations were concerned with numerical computation.