COMPUTERS

A computer is really a very specific kind of a counting machine. It can do arithmetic problems faster than any person alive. By means of electric processes it finds the answer to a very difficult and complicated problem in a few seconds.

A computer can "remember" information you give it. It keeps the information in its "memory" until you need it. There are different kinds of computers. Some can do only one job. There are special-purpose computers. Each specific problem requires a specific computer. One kind of computer helps us build a spaceship, another kind helps us navigate it. A special-purpose computer is built for this purpose alone and cannot do anything else.

But there are some computers that do many different jobs. They are called the general-purpose computers. There are the big "brains" that solve the most difficult problems of science. We used to think of a computer as a large machine that took up a whole room. But today computers are becoming smaller and smaller. Though these small devices are called microcomputers or minicomputers, they are still true computers.

The most important parts of the general-purpose computer are as follows: 1) memory, where information is kept; 2) an arithmetic unit for performing calculations, 3) a control unit for the correct order of operations; 4) input devices; 5) output devices for displaying the results of calculations. The input and output devices are called peripherals.

There are several advantages in making computers as small as one can. Sometimes weight is particularly important. A modern plane carries many heavy electronic apparatus. If it is possible to make any of them smaller, it can carry a bigger weight. But weight is not the only factor. The smaller the computer is, the faster it can work. The signals go to and for at a very high but almost constant speed.

Some of the first computer cost millions of dollars, but people quickly learned that it was cheaper to let a million dollar computer make the necessary calculations than to have a hundred clerks who try to do this by hand. Scientists found that computer made fewer mistakes and could fulfil the tasks much faster than almost any number of people by usual methods. The computers became popular. As their popularity grew the number of factories that produce them also grew.

... is built (to be built) – построен ... used to - привыкли

... are called (to be called) - называются ... performing - выполнение (вычислений)

... displaying the results - отображение результатов

If it is possible - Если возможно

Answer the following questions:

1.What is a computer?

2.What is the difference between special- and general-purpose computers?

3.What are the main parts of the general-purpose computer?