Analog and digital computers

 

Computers are divided into two main types, analog computers and digital com­puters.

  Analog computers measure change in continuous physical or electrical states,such as pressure, temperature, voltage, length, volume, or shaft rotations. A speedometer is an example of an analog device. The computer measures the rotations of the drive shaft and uses a pointer to indicate the speed of the car.

Unlike analog computers, digital computers count. In a digital computer, data is represented by discrete "on" and "off" (conducting/non-conducting or yes/no) states of the computer's electronic circuitry. Numbers, letters, and symbols are represented by a code based on the binary number system, a number system consisting of two digits, 1 and 0. This number system is well suited to represent the on/off states of electric current. The digital computer must convert all data to binary form.

The digital computer has some advantages over the analog computer. Within the limits of its circuits, a digital computer can perform three basic functions:

1. Arithmetic operations (addition, subtraction, multiplication, and division);

2. Logical comparisons of relationships among values (greater than, less than, equal to);

3. Storage and retrieval operations.

 

ACTIVE WORDS AND WORD COMBINATIONS:

 

оperation of computers - режим работы компьютеров;

task- задача, работа, индивидуальное задание

to act – действовать, влиять                     

circuits-цепь, контур, электрическая схема     

digital- цифровой                   
pointer – указатель, стрелка                    
discrete- дискретный, отдельный                            
electric current- электрический ток

means- средства, способ

by means of – при помощи, посредством
to conduct- проводить
analog- аналоговый
to measure- измерять
to count- считать
binary number system- двоичная система счисления

envisage –рассматривать

yеt – тем не менее, даже

marvel – чудо, диво, замечательная вещь
to perform computations –выполнять вычисления

                                   Assignments:

                                                       

I. Pronounce the words and word combinations and give their Russian equivalents:

superhuman intelligence, temperature, to count, electronic, circuit, symbol, digit, to convert, binary, arithmetic, to retrieve, physical, continuous, to pull.

 

II. Form Participle II of the following verbs:

  hear, have, perform, handle, be, count, suit.

 

III. Put  different questions to the following sentences:

1. A computer performs tasks defined by humans in the form of programs.

2. The digital computer must convert all data to binary form.

3. The computer performs computations.

IV. Match the English terms with their Russian equivalents:
data                цифра
source       проверять
error            память
to connect     экран

to access    распределять

screen        запись

to print    данные

to distribute соединять

to process      источник

record       осуществлять доступ

to check         печатать

memory         ошибка
digit               обрабатывать

 

 

V. Translate into Russian:

Yet a computer has no intelligence of its own; a computer handles data by means of simple yes/no operations; based on the binary number system; the digital computer must convert data to binary form; logical comparisons of relationships among values; computer's electronic circuitry; directed by programs; within the limits of its circuits.

 

VI. Find in the text the English equivalents for the following word combina­tions:

Когда некоторые люди слышат слово «компьютер»; электронное чудо с интеллектом сверхчеловека; он (компьютер) извлекает данные из запоминающего устройства; компьютеры делятся на два основных типа; в отличии от остальных компьютеров; пример аналогового устройства, преимущества над аналоговыми компьютерами.

 

VII. Find the term for each definition:

1. Being or using information in the form of numbers zero and one.

2. To discover the exact size, amount, etc of something.

3. To allow electricity to go through

4. A movement of electricity in a particular direction.

 

VIII. Make up your own sentences with the following words or word com­binations:

Electric current, binary number system, to measure, pointer, discrete, analog, to conduct.

 

IX. Agree or disagree with the statements:

1. Analog computers have some advantages over digital ones.

2. A digital computer cannot perform multiplication and division operations.

3. A computer has no intelligence of its own.

4. Analog computers measure change in continuous physical or electrical states.

5. The binary number system consists of two digital 0 and 1.

6. Analog computers must convert all data to binary form.

7. The work of a computer is directed by programs.

8. Both digital and analog computers can count.

 

X. Answer the following questions:

1. What do some people envision when they hear the word computer?

2. Does a computer have any intelligence of its own?

3. By what means does a computer handle data?

4. What are the main types of computers?

5. What is the main difference between analog and digital devices?

6. What tasks do analog computers perform?

7. Is a speedometer an example of a digital computer?

8. What is the binary number system?

9. Why must the digital computer convert all data to binary form?

10. What are the basic functions a digital computer can perform?