Kinds of computers

Introduction

Three classes – every computer has a processor, memory and some type of I/0. From there computers can be classified as microcomputers, minicomputers, or mainframes. Each class overlaps the other. Generalized definitions of the three follow.

A microcomputer contains a microprocessor, usually located on one LSI (large-scale imtergrated) chip or small LSI chip set. The processor's word length is between 4 and 8 bits.

Most microcomputers have at least 256 words of memory. A minicomputer's word length is between 12 and 16 bits. And its minimum memory size is 4 OS'6 word4.

A mainframe, or so called large computer, usually has a word length of 52 bits or more and a minimum memory of l6384 words.

II. Read and memorize the words:

1. immense amounts of data -огромноеколичестводанных

2. to take use of –использовать

3. to be dealt with - бытьзанятымчем-либо

4.to transfer for rapid access - передатьдлябыстрогодоступа

5. a repertoir - набор (команд)

6. to be executed - бытьвыполненным

7. to accomplish – выполнять

8. to make up – составлять

9. tremendous speed - огромнаяскорость

10.to work out – вырабатывать

11. tosimulate – моделировать

12. means – средства

13. essentially - главным образом

14. to involve - включать измерения

15. torequire – требовать

16. toaccommodate – разместить

17. tobecapableofdoingnuth - быть в состоянии что-либо сделать

Mainframes

Large computer systems, or mainframes, are those computer systems found in computer installations processing immense amounts of data. They make use of very high-speed main memories into which data and programs to be dealt with are transferred for rapid access. These powerful machines have a larger repertoir of more complex instructions which can be executed more quickly. Where a smaller computer may take several steps to perform a particular operation, a larger machine may accomplish the same thing with one instruction.

These computers can be of two types: digital or analog. The digital computer or general-purpose computer as it is often make up about 90% of the large computers now in use. It gets name from the name of the data that are presented to it and which consist of digits.

The digital computer can do calculations in steps at tremendous speed and with great accuracy. Digital computer programming is by far the most commonly used in electronic data processing for business or statistical purposes. The analog computer works something like a car speedometer, in that it continuously works out calculations. It is used essentially for problems invo1ving measurements. I t can simu1ate or imitate different measurements by electronic means. Both of these types are made of electronic computers that may require a larger room to accommodate them. At present, the digital computer is capable of doing anything the analog once did. Moreover, it is easier to program and cheaper to operate. A new type of scientific computer system called the hybrid computer has now been produced that combines the two types into one.