6. Computers

New words and word-combinations to be remembered:

set of instructions набір інструкцій

memory unit блок пам'яті

binary-coded form форма двійкового кодування

Integrated circuit chip кристал інтегральної схеми

Input/output interface chip кристал інтерфейсу вводу/виводу

large-scale integration велика інтегральна схема

Industrial control system система промислового управління

binary digit двійкова цифра (число, знак, символ)

timing circuit схема синхронізації

to execute виконувати

From the first electronic digital computers of the forties to to-day's versatile computers and most up-to-date microcomputers very little has changed as far as basic computer operation is concerned.

To-day digital computers still use the same logical operations as their predecessors. There are many basic concepts that can be applied to all types of computers, including microcomputers.

The computer is faster and more accurate than people, but unlike most people it must be given a complete set of instructions that tell it exactly what to do at each step of its operation. This set of instructions, called a programme, is prepared by one or more persons for each job a computer is to do. These programmes are placed in the computer's memory unit in binary-coded form, with each instruction having unique code.

Computers in present use range considerably: from tiny things to big fellows. The microcomputer is the smallest and the newest member ol t he computer family. It usually consists of several integrated circuit chips, including a microprocessor chip, memory chips, and input/out-put interface chips which are a result of tremendous advances in large-scale integration.

Minicomputers are larger than microcomputers. They are widely used in industrial control systems, scientific institutions and research laboratories. Although more expensive than microcomputers minicom­puters continue to be widely used because they are generally faster and possess more capabilities.

The largest computers (maxicomputers) are those found in research centres, large scientific laboratories, big universities.

Most of the computer principles and concepts are common to all categories of computers, although there can be tremendous variations from computer to computer.

The computer programmer provides a programme of instructions and data which specifies every detail of what to do, how to do, and when to do it. The computer is simply a high-speed machine which can manipulate data, solve problems, and make decisions, all under the control of the programmer. If the programmer makes a mistake in the programme or puts in the wrong data, the computer will produce wrong results.

Every computer contains five essential elements or units: the arithmetic logic unit, the memory unit, the control unit, the input unit and the output unit.

The arithmetic logic unit is the area of the computer in which arithmetic and logic operations are performed on data.

The memory unit stores groups of binary digits (words) that can represent instructions (programme) which the computer is to perform and the data that are to be operated on by the programme.

The input unit consists of all the devices used to take information and data that are external to the computer and put it into the memory unit.

The output unit consists of the devices used to transfer data and information from the computer to the outside world.

The control unit directs the operation of all the other units by providing timing and control signals. This unit contains logic and timing circuits that generate the signal necessary to execute each instruction in a programme.

Answer the following questions:

1. What is the difference between microcomputers and minicom­puters?

2. What do we call a programme?

3. Where are programmes in binary-coded form placed?

4. Where are minicomputers often used?

5. What kinds of computers are used in scientific laboratories and big universities?

6. What is the computer and what can it do?

7. What are five essential elements of the computer?

Speak on computers using the following word-combinations:

The computer:

— to consist of 5 basic units: the input unit, memory unit, the arithmetic logic unit, the control unit, the output unit.

The microcomputer:

— to consist of several integrated circuit chips, microprocessor chip, memory chips, input/output interface chips.

The minicomputer:

— to be larger than microcomputer;

— to be widely used in industrial control systems, scientific institu­tions, research laboratories;

— to be more expensive but faster, to have more capabilities.

The maxicomputer:

— to be found in research centres, large scientific laboratories, big universities.