2. Ответьте на вопросы, используя информацию текста.

1. What are the functional units of a digital computer?

2. What units make up the central peocessing unit?

3. How is computer system organized?

4. What are the two main types of storage units?

5. What do they contain?

6. What is the function of a primary storage?

7. Why is primary storage called memory?

8. In what respect does computer memory differ from human memory?

9. What are codes are based on?

10. What is secondary storage and what is it used for?

3. Найдите в тексте английские эквиваленты следующих словосочетаний.

Функциональный блок, цифровой компьютер, устройство ввода, устройство управления, центральный процессор, первичное запоминающее устройство, вторичное ЗУ, оперативное ЗУ, внутренняя память, промежуточные результаты, подобие функции человеческого мозга, двоичная система счисления, объем информации, последовательность символов, полупроводник, доступный.

4. Переведите предложения, содержащие Perfect Participle Active и Perfect Participle Passive.

1. Having finished the research the scientists made the analysis of the data obtained.

2. The designer left the office having looked through all the documents.

3. Having discussed the functions of storage units we passed on to the consideration of control processing unit.

4. Having limited the information capacity of a single bit to two alternatives the computer designers expressed data by a combination of bits.

5. Having translated the program into machine language the computer architect put the program into the machine.

6. Having been coded the instruction was transmitted to the central processing unit.

7. Having been transmitted to the central processing unit the instruction made arithmetic-logical unit perform some computations.

8. Having been regulated by the operator the equipment operated well.

9. Data having been entered correctly into the computer component of a data processing system, the need for further manipulation by humans is eliminated.

10. Having been well prepared for the examination the pupils could answer all the questions the teacher asked them.

5. Раскройте скобки, употребляя правильную неличную форму глагола.

1. Computing is a concept (embraced, embracing, for embracing) not only arithmetic, but also computer literacy.

2. We can make the computer do what we want (to input, by inputting) signals (turning, turned, without turning) switches on and off.

3. Computers have a means (by communicating, of communicating, communicated) with the user.

4. Computers work according to the instructions (giving, given, to give) to it by users.

5. The transistor (inventing, invented, for inventing) in 1948 completely changed the vacuum tubes.

LESSON № 7

1. Прочтите и переведите следующий текст:

STORAGE DEVICES

Storage media are classified as primary storage or secondary storage on the basis of combinations of cost, capacity and access time. The cost of storage devices is expressed as the cost per bit of data stored. The most common units of cost are cents, millicents (0.001 cents) and micro cents (0.000001 cents). The time required for the computer to locate and transfer data to and from a storage medium is called the access time for that medium. Capacities range from a few hundred bytes of primary storage for very small computers to many billions of bytes of archival storage for very large computer systems.

Memories can be classified as electronic or electromechanical. Electronic memories have no moving mechanical parts, and data can be transferred into and out of them at very high speeds. Electromechanical memories depend upon moving mechanical parts for their operation, such as mechanisms for rotating magnetic tapes and disks. Their data access time is longer than is that of electronic memories; however, they cost less per bit stored and have larger capacities for data storage. For these reasons most computer systems use electronic memory for primary storage and electromechanical memory for secondary storage.

Primary storage has the least capacity and is the most expensive. However, it has the fastest access time. The principal primary storage circuit elements are solid-state devices: magnetic cores and semiconductors. For many years magnetic cores were the principal elements used in digital computers for primary storage. The two principal types of semiconductors used for memory are bipolar and metal-oxide semiconductors (MOS). The former is the faster, the latter is more commonly used at present. Because data can be accessed randomly, semiconductor memories are referred to as random-access memory or RAM.

There is a wide range of secondary storage devices. Typical hardware devices are rotating electromechanical devices. Magnetic tapes, disks and drums are the secondary storage hardware most often used in computer systems for sequential processing. Magnetic tape which was invented by the Germans during World War II for sound recording is the oldest secondary storage medium in common use. Data are recorded in the form of small magnetized “dots” that can be arranged to represent coded patterns of bits.

Tape devices range from large-capacity, high-data-rate units used with large data processing systems to cassettes and cartridges used with small systems. Magnetic disk storage introduced in the early 1960s has replaced magnetic tape as the main method of secondary storage. As contrasted with magnetic tapes, magnetic discs can perform both sequential and random processing. They are classified as moving -head, fixed-head or combination moving-head and fixed-head devices. Magnetic disks are the predominant secondary storage media. They include flexible or floppy discs called diskettes. The “floppies” were introduced by IBM in 1972 and are still a popular storage medium to meet the demands of the microcomputer market.

Words:

Medium (pl. media)- носитель, среда

Capacity- емкость, объем памяти, пропускная способность

Data access time- время доступа к данным

Per bit- на единицу информации

To transfer- передавать (ся), переносить

To rotate- вращать, чередовать

Solid-state device- твердотельный прибор

Magnetic core- магнитный сердечник

Bipolar semiconductor- биполярный полупроводник

Metal-oxide semiconductor (MOS) - структура металл-оксид-проводник

Randomly- произвольно

Random-access memory (RAM) - оперативное запоминающее устройство (ОЗУ)

Sound recording- звукозапись

To arrange- размещать, располагать, устанавливать

Moving-head device- устройство с двигающейся головкой

Predominant- преобладающий, доминирующий

Flexible- гибкий, изменяемый

Floppy disc- гибкий диск(ета)

To meet the demands- удовлетворять потребности

To range- классифицировать, располагать в порядке

Magnetic disc storage- ЗУ на магнитном диске