LESSON 4

ANALOGUE AND DIGITAL COMPUTERS [1]

Task 1. Read and translate the text:

Задание 1. Прочитайте и переведите текст:

An analog computer is a device that simulates the behavior of another (system, person) usually a physical system. A very simple and widely used analogue (computer, car) is the slide-rule on which distances are equivalent to logarithms of numbers. The (devices, pictures) known as analogue computers are assemblies of electronic or electrical circuits the behavior of which is analogous to another (mechanical) system's (behavior, progress).

The evolution of the adding (machine, glass) has culminated in electronic digital computers in which electronic (signals, system) are used as the operative discrete signals. The simplest (digital, electronic) computer is the human hand, from which the decimal (system, pictures) is derived. The first man-made digital computer was probably the abacus, which is still used in many (countries, signals). The basic sections of digital computers are therefore:

Input: receives the "raw data" and (instructions, person) from external sources and converts them into a suitable form for a computer to work on.

Store: memorizes (numbers, countries) and instructions.

Calculator: does mathematical operations.

Control: initiates and follows the (operations, countries).

Output: presents the result of the calculations in an acceptable form.

When an ordinary (desk, pictures) calculating machine is used, the operator controls the sequence of (operations, signals). He supplies the input data and records the results. Also he may have to provide additional (information, numbers) from tables and other sources during the calculation. In the case of electronic (computers, glass) working at extremely high speeds, the human operators are replaced by automatic devices. It is necessary to provide a store to hold both the numbers that are fed into the (compeer, countries) and the operating instruction. The digital computer differs from the analogue computer in that it deals with numbers and not physical quantities.

Task 2. Answer the following questions:

Задание 2. Ответьте на следующие вопросы:

1. How many types of computers do you know? What are they?

2. What are their advantages and disadvantages, comparing one to another?

3. What are the basic sections of digital computers?

4. What is a device that simulates the behavior of another system in all its states?

5. What differs the analogue computer?

6. What computer is still used in many countries?

7. Has the evolution of the adding machine culminated in electronic digital computers?

8. When does the operator control the sequence of operations?

9. What does the operator supply?

10. What are the basic sections of digital computers?

Task 3. Match the English words given below with their Russian equivalents:

Задание 2. Соотнесите следующие ключевые слова с соответствующим переводом:

• to simulate • circuits • a quantity • to derive • an instruction • to provide • input data • raw data • to supply • a sequence of operations • to convert • digital • a calculator

• цифровой • превращение • последовательность операций • обеспечивать • калькулятор • величина • устанавливать • команда • снабжать • входные данные • необработанные данные • цепи • моделировать

Task 4. Find these words and word — combinations in the text:

Задание 4. Найдите в тексте предложения, содержащие нижеследующие слова и выражения:

• a decimal system

• operative discrete signals

• a calculating machine

• automatic devices

• a sequence of operations

• electronic signals

• external sources

Task 5. Complete the following sentences corresponding to the contents of the text:

Задание 5. Закончите предложения:

1. An analogue computer is....

2. The devices known as analogue computers are....

3. The digital computer differs from the.....

4. The simplest digital computer is.....

5. The evolution of the adding machine has.....

6. He supplies the....

7. The first man-made digital computer was …..

8. A very simple and widely used... of numbers.

9.... the operator controls the sequence of operations.

10.... is used... the sequence of operations.

Task 6. Say whether the statements given below are true or false:

Задание 6. Определите истинность или ложность следующих предложений:

1. A digital computer is a device that simulates the behavior of another system, often a physical system, in all its states.

2. A very complex widely used analogue computer is the slide-rule on which distances are equivalent to logarithms of numbers.

3. The digital computer doesn't differ from the analogue computer.

4. The second man-made digital computer was probably the abacus, which is still used in many regions.

5. A very simple and widely used analogue computer isn't the slide-rule on which distances are equivalent to logarithms of number.

6. The simplest digital computer isn't the human hand.

7. The evolution of the adding machine has culminated in electronic digital computers in which electronic signals are not used as the operative discrete signals.

8. When an ordinary desk calculating machine is used, the operator can't controls the sequence of operations.

9.The human operators are replaced by automatic devices.

Task 7. Translate the sentences from Russian into English:

Задание 7. Переведите с русского языка на английский:

1. Цифровой компьютер отличается от аналогового компьютера тем, что он работает только с числами.

2. Оператор управляет последовательностью действий, выполняемых компьютером; он вносит данные в компьютер и делает запись полученных результатов.

3. Аналоговый компьютер — устройство, которое моделирует поведение другой системы.

4. Первый искусственный цифровой компьютер был, вероятно, «абака», который все еще используется во многих странах.

5. Развитие счетной машины завершилось развитием электронных цифровых компьютеров.

6. Память: запоминает числа и инструкции.

7. Вывод: предоставляет результат вычислений в приемлемой форме.

8. Калькулятор выполняет математические действия.

Task 8. Make the sentences negative and interrogative:

Задание 8. Преобразуйте следующие предложения в вопросительную и отрицательную форму:

1. An analog computer is a device.

2. The digital computer differs from the analogue computer.

3. The first man -made digital computer was probably the abacus.

4. The human operators are replaced by automatic devices.

5. Store memorizes numbers and instructions.

Task 9. Write the plural form of the following nouns:

Задание 9. Образуйте множественное число следующих существительных:

a computer, a system, a state, a distance, a number, a device, a circuit, a quantity, a hand, a country, a signal, an operator, an instruction, a source, an operation, a result, a table, speed.