Ознакомьтесь с терминами текста 2.

medium (pi. media) — носитель; среда capacity — емкость; объем (памяти); пропускная спо­собность

media capacity — емкость носителя

data access time — время доступа к данным

per bit — на единицу информации

to transfer— передавать(ся); переносить(ся); пересы-лать(ся)

archival storage — архивное ЗУ; архивная память to depend — зависеть от; полагаться, рассчитывать на to rotate — вращать(ся); чередовать(ся); сменять(ся) reason — причина; основание; довод; обосновывать;

делать вывод

solid-state device — твердотельный прибор magnetic core — магнитный сердечник

Английский язык. Основы компьютерной грамотности           90

bipolar semiconductor — биполярный полупроводник

metal-oxide semiconductor (MOS) — структура металл-оксид-полупроводник randomly — произвольно

random-access memory (RAM) — оперативное запомина­ющее устройство (ОЗУ)

sound recording — звукозапись

to arrange — размещать; располагать; устанавливать;

монтировать tape device — ЗУ на магнитной ленте

to range — классифицировать; располагать в порядке; лежать в диапазоне

magnetic disc storage — ЗУ на магнитном диске

moving-head device — устройство с двигающейся голов­кой

predominant — преобладающий; доминирующий flexible —гибкий; настраиваемый; изменяемый floppy (disk) — гибкий диск(ета); ЗУ на гибком диске to meet the demands — удовлетворять потребности

9. Прочтите текст 2 и скажите, как вы понимаете термин «запоминающая среда» и какие компоненты ее состав­ляют. Переведите текст.

Text 2. 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 microcents (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 may be classified as electronic or electromechani­cal. Electronic memories have no moving mechanical parts, and

91                                                               Unit 7. Storage

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 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 discs 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.

Английский язык. Основы компьютерной грамотности               92

10. Ответьте на вопросы, используя информацию текста.

1. How are storage media classified? 2. How is the cost of storage devices expressed? 3. What is the access time for stor­age media? 4. How does the storage capacity range? 5. What are the two main types of storage devices? 6. What are electronic storage devices? 7. What are the principal primary storage cir­cuit elements? 8. What are the main secondary storage devic­es? 9. What is the oldest secondary medium and when was it invented? 10. What is a floppy?

11. Найдите в тексте английские эквиваленты следующих
словосочетаний:

Запоминающие устройства; носители памяти; первич­ные ЗУ; вторичные ЗУ; время доступа; стоимость ЗУ; диа­пазон емкости памяти; архивная память; движущиеся ме­ханические части; вращающиеся магнитные ленты и диски; по этим причинам; твердотельные устройства; маг­нитные сердечники; полупроводники; оперативное ЗУ; аппаратное обеспечение вторичной памяти; звукозапись; . намагниченные точки; представлять зашифрованную ком­бинацию единиц информации; в отличие от магнитных лент; последовательная и произвольная обработка; устрой­ства с движущейся и фиксированной головкой; удовлет­ворять потребности; гибкий диск.

Опишите схему.

93__________________________________ Unit 7. Storage

13. Переведите предложения, содержащие всевозможные
формы причастий: Participle I, Participle II, Perfect
Participle Active и Perfect ParticiplePassive.

1.Electromechanical memories depend upon moving me­chanical parts for their operation. 2. The time required for the computer to locate and transfer data to and from a storage me­dium is called the access time. 3. Being not visible software makes possible the effective operation of computer system. 4. Having invented magnetic tapes the Germans used them as the secondary storage medium. 5. When properly programmed computers don't make computational errors. 6. Having been in­troduced in the early 1960s magnetic disc storage has replaced magnetic tape storage. 7. The control unit interpreting instruc­tions is one of the important parts of any computer system. 8. Data recorded in the form of magnetized dots can be arranged to represent coded patterns of bits. 9. As contrasted with mag­netic tapes magnetic discs can perform both sequential and ran­dom processing. 10. While having no moving mechanical parts electronic memories can transfer data at very high speed.

Выполните письменный перевод текста по вариантам.

DIGITAL COMPUTER OPERATION

1. A digital computer is a machine capable of performing operations on data represented in digital or number form. The individual operations performed by a digital computer are very simple arithmetic or logical processes involving the manipula­tion of the bits in words or characters of information. The great power of any digital computer rests in the ability to store large volumes of data and to perform these operations at extremely high speed.

In most electronic digital computers the method of number representation is based on the system of binary notation. The binary notation system is most widely used because of the con­venience in constructing logical circuits and storage devices ca­pable of handling data in this form. For example, a magnetic memory unit consists of many thousand individual magnetic cells, each of which can be energized in either of two ways to represent the binary digits 0 or 1. If these cells are grouped to form words or binary coded characters, information can be

Английский язык. Основы компьютерной грамотности           94

stored for processing in units of specified size. In the same way, digital data can be recorded as a series of magnetized spots on a magnetic tape or a magnetic disk.

2. The computer has pervaded most fields of human activity and is the most important innovation of our age. Born out of the technology of communication, it is capable of handling enormous amounts of information at tremendous speeds. What makes it so potent is the fact that a single mechanism can per­form any information-processing task. The same mechanism can control industrial processes, guide space vehicles or help to teach children. This diversity of tasks is made possible by the simple idea of the stored program.

A program is the enumeration of determining commands. It specifies the method used for the solution of a problem in de­tail. When the machine is. in operation, both the commands and the numbers to be processed are constantly being taken out of and put into a depository of information known as a memory.

It can be seen that the processes performed by a digital com­puter are essentially simple. These operations can be performed at extremely high speeds and with a high degree of coordina­tion between the different functional units of the hardware sys­tem, and this ability means that digital computers can under­take highly complex tasks.

15. Прочтите внимательно текст. Составьте на английском языке план текста, выделив основные его темы. План можно составить в вопросной, назывной или тезисной форме. Познакомьтесь с образцами планов, представ­ленными после текста; сравните со своим планом.

MEMORY

It is interesting to note that memory, one of the basic com­ponents of the computer, is often called storage. It stores cal­culation program, the calculation formulae, initial data, inter­mediate and final results. Therefore, the functions of the computer memory may be classified in the following way. Firstly, the computer memory must store the information transmitted from the input and other devices. Secondly, memory should produce the information needed for the computation process to all other devices of the computer.

95                                                                                       Unit 7. Storage

Generally, memory consists of two main parts called the main, primary or internal, memory and the secondary, or ex­ternal memory. The advantage of the primary memory is an extremely high speed. The secondary memory has a compara­tively low speed, but it is capable of storing far greater amount of information than the main memory. The primary storage takes a direct part in the computational process. The second­ary storage provides the information necessary for a single step in the sequence of computation steps.

The most important performance characteristics of a stor­age unit are speed, capacity and reliability. Its speed is measured in cycle time. Its capacity is measured by the number of ma­chine words or binary digits. Its reliability is measured by the number of failures (отказ) per unit of time.

План в вопросной форме.

1. What is memory?

2. What is the function of memory?

3. What are the main parts of memory?

4. What are advantages and disadvantages of a storage unit?

5. What are their functions?

6. What are performance characteristics of the main and
secondary memory?

7. What units are performance characteristics measured by?

План в назывной форме

1. The definition of memory.

2. The main functions of memoiy.

3. Classification of memory.

4. Advantages and disadvantages of memory components.

5. The functions of memory components.

6. Performance characteristics of memory.

7. The units for measuring the performance characteristics
of memory.

План в тезисной форме.

1. Memory is one of the basic components of the comput­
er.

2. Memory stores initial data, intermediate and final results.

3. It produces the information needed to other devices of
the computer.

Английский язык. Основы компьютерной грамотности               96

4. Memory consists of the main (internal) and the second­
ary (external) storage.

5. The main memory has high speed, but small capacity; the
secondary memory possesses lower speed but greater ca­
pacity.

6. The main memory performs computation; the secondary
memory provides information sequentially, step by step.

7. The performance characteristics — speed, capacity and
reliability — are measured by cycles, binary digits and the
number of failures per unit of time.