What is a computer?

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

A computer can «remember» information you give it. It stores the information in its «memory» until it is needed. When you are ready to solve a problem, you can get the computer to sort through its stored facts¹ and use only the proper ones. It works the problem with lightning speed. Then it checks its work to make sure there are no mistakes.

There are different kinds of computers. Some do only one job over and over again. These are special-purpose computers. Each specific application requires a specific computer. One kind of computer can help us build a spacecraft another kind of computer can help us navigate that spacecraft. A special-purpose computer is built for this purpose alone and cannot do anything else.

But there are some computers that can do many different jobs. They are called general-purpose computers. These are the «big brains» that solve the most difficult problems of science. They answer questions about rockets and planes, bridges and ships – long before these things are even built.

We used to think of a computer as a large machine with many buttons and flashing lights that took up a whole room.² But today computers are becoming smaller and smaller and are even being put inside other devices. Though these small devices are called microcomputers or minicomputers, they are still true computers.

Notes

1 you can get the computer to sort through its stored facts	– можливо змусити ЕOМ розсортувати накопичені файли;
2 took up a whole room2	– займав ціле приміщення.

What can computer do?

Computers are thought to have many remarkable powers. However, most computers whether large or small, have three basic capabilities. First, computers have circuits for performing arithmetic operations, such as addition, subtraction, division, multiplication and exponentiation. Second, computers have a means of communicating with the user. After all, if we couldn’t feed information in and get results back, these machines wouldn’t be of much use. However, certain computers for example minicomputers and microcomputers are used to control directly things such as robots, aircraft navigation systems, medical instruments, etc.

Third, computers have circuits, which can make decisions. Computer can solve a series of problems and make hundreds, even thousands, of logical decisions without becoming tired or bored. It can find the solution to a problem in a fraction of the time it takes a human being to do the job. A computer can replace people in dull, routine tasks, but it has no originality; it works according to the instructions given to it. A computer cannot do anything unless a person tells it what to do and gives it the appropriate information.

From the history of computers

The first generation of computers, which used vacuum tubes, came out in 1950. These computers could perform thousands of calculations per second. About 1960, the second generation of computers was developed and these could perform work ten times faster than their predecessors. The reason for this extra speed was the use of transistors instead of vacuum tubes. Second-generation computers were smaller, faster. One of the best of these second-generation computers is the Soviet BECM-6 (big electronic counting machine).

The third-generation computers began to appear in 1965. These computers could do a million calculations a second, which is 1000 times as many as first-generation computers: they are controlled by tiny integrated circuits and are consequently smaller and more dependable. Fourth-generation computers have now arrived. They are based on ICs greatly reduced in size due to microminiaturization, which means that the circuits are much smaller than before. As many as 1000 tiny circuits now fit onto a single chip. Fourth-generation computers are 50 times faster than third-generation computers.

The most recent mainframe computers based on very large scale integration are becoming available in the mid-1980’s.