Digital computers

(1) There are two fundamentally different types of computers: analog and digital. The former type solver problems by using continuously changing data such as voltage. In current usage, the term "computer" usually refers to high-speed digital computers. These computers are playing an increasing role in all branches of the economy.

(2) Digital computers based on manipulating discrete binary digits (1s and 0s). They are generally more effective than analog computers for four principal reasons: they are faster; they are not so susceptible to signal interference; they can transfer huge data bases more accurately; and their coded binary data are easier to store and retrieve than the analog signals.

(3) For all their apparent complexity, digital computers are considered to be simple machines. Digital computers are able to recognize only two states in each of its millions of switches, "on" or "off", or high voltage or low voltage. By assigning binary numbers to there states, 1 for "on" and 0 for "off", and linking many switches together, a computer can represent any type of data from numbers to letters and musical notes. It is this process of recognizing signals that is known as digitization. The real power of a computer depends on the speed with which it checks switches per second. The more switches a computer checks in each cycle, the more data it can recognize at one time and the faster it can operate, each switch being called a binary digit or bit.

(4) A digital computer is a complex system of four functionally different elements: 1) the central processing unit (CPU), 2) input devices, 3) memory-storage devices called disk drives, 4) output devices. These physical parts and all their physical components are called hardware.

(5) The power of computers greatly on the characteristics of memory-storage devices. Most digital computers store data both internally, in what is called main memory, and externally, on auxiliary storage units. As a computer processes data and instructions, it temporarily stores information internally on special memory microchips. Auxiliary storage units supplement the main memory when programmes are too large and they also offer a more reliable method for storing data. There exist different kinds of auxiliary storage devices, removable magnetic disks being the most widely used. They can store up to 100 megabytes of data on one disk, a byte being known as the basic unit of data storage.

IX. Письменно ответьте на вопросы.

1) What types of computer do you know?

2) What physical parts of a digital computer do you know?

3) How do most digital computers can store data?

Вариант 4

I. Перепишите следующие предложения. Определите по грамматическим признакам, какой частью речи являются слова, оформленные окончанием -s и какую функцию это окончание выполняет, т. Е. Служит ли оно:

а) показателем 3 - го лица единственного числа в Present Indefinite;

б) признаком множественного числа имени существительного;

в) показателем притяжательного падежа имени существительного (см. образец выполнения 1)

Переведите предложения на русский язык.

1. He lives in Moscow.

2. This man works at our office.

3. My uncle writes poems.

4. My father works at an Institute.

5. His daughter’s toy is on the floor.

II. Переведите следующие предложения, содержащие разные формы сравнения, и переведите их на русский язык.

1. Mathematics was the most difficult subject for me at school.

2. English is as difficult as German.

3. My com­position is not as long as yours.

4. The bookcase was in the farthest corner of the room.

5. The Baltic Sea is not so warm as the Black Sea.

6. These shoes are not worse than yours. I advise you to buy them.

III. Заполните пропуски глаголами to be, to have в Present, Past, Future Indefinite. Переведите предложения на русский язык.

1. The weather … good today.

2. She … clever girl.

3. The weather yesterday … very warm.

4. There … many examinations next term.

5. She … green eyes.

IV. Перепишите следующие предложения, определите в них видо - временные формы глаголов и укажите их инфинитив, переведите предложения на русский язык.

1. Don't shut the window. It has just been opened.

2. I often write to my sister.

3. They are meeting foreign students now.

4. She looked at the blackboard and copied the new words.

5. She was making breakfast at 8 o'clock.

6. How long have you known each other?

7. I have never seen such a film before.

V. Употребите нужную форму местоимений: личные, притяжательные, вопросительные, ука­зательные, относительные.

1. (They) . . . knowledge of the subject is very poor.

2. He teaches (we, us)… English.

3. All (our, ours) … clothes were dirty, and (my, mine) … especially.

4. (this, these, that, those) ... is my English book.

VI. Перепишите и письменно переведите предложения на русский язык, обращая внимание на перевод неопределенных местоимений и их производных.

1. There is somebody there.

2. There is nobody there.

3. Is there anybody in the library?

4. Is there anything behind the curtain? — No, there is nothing there.

VII. Перепишите следующие предложении, подчеркните в каждом из них модальный глагол и его эквивалент. Переведите предложения на русский язык.

1. They can understand French.

2. He is able to do it.

3. May I go to the post-office with Mike?

4. You must learn the words.

5. It was so stuffy there that we could hardly breathe.

VIII. Прочтите и устно переведите текст. Письменно переведите 1-3 абзацы.