Four generations of computers 


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Four generations of computers



 

The first vacuum tubes computers are referred to as first generation computers, and the approximate period of their use was from 1950 to 1959. UNIVAC 1 (Universal Automatic Computer) is an example of these computers which could perform thousands of calculations per second. Those devices were not only bulky, they were also unreliable. The thousands of vacuum tubes emitted large amounts of heat and burned out frequently.

The transistor, a smaller and more reliable successor to the vacuum tube, was invented in 1948. So-called second generation computers, which used large numbers of transistors were able to reduce computational time from milliseconds to microseconds, or millionths of seconds. Second-generation computers were smaller, faster and more reliable than first-generation computers.

Advances in electronics technology continued, and microelectronics made it possible to reduce the size of transistors and integrate large numbers of circuit elements into very small chips of silicon. The computers that were designed to use integrated circuit technology were called third generation computers, and the approximate time span of these machines was from 1960 to 1979. They could perform many data processing operations in nanoseconds, which are billionths of seconds.

Fourth generation computers have now arrived, and the integrated circuits that are being developed have been greatly reduced in size. This is due to microminiaturization, which means that the circuits are much smaller than before; as many as 100 tiny circuits are placed now on a single chip. A chip is a square or rectangular piece of silicon, usually from 1/10 to 1/4 inch, upon which several layers of an integrated circuit are etched or imprinted, after which the circuit is encapsulated in plastic or metal.

 


Текст 7 PERSONAL COMPUTERS

 

Задание 1 Ознакомьтесь с терминами текста и подготовьтесь к лексическому диктанту

 

personal computers — персональные компьютеры

competitive operating systems — конкурирующая операционная система

IBM (International Business Machine) — фирма по производству компьютеров

to enter the fray — ввязаться в драку

computer of choice — лучший компьютер

to fall by the wayside — остаться в стороне; уступить дорогу

to survive onslaught — выдержать конкуренцию

word size — размер слова; разрядность двоичного слова

soft - copy output — вывод электронной, программно-управляемой копии

hard - copy output — вывод «твердой» печатной копии

online storage — неавтономное хранение данных в ЗУ

offline storage — автономное хранение данных отдельно от компьютера

input media — носитель для входных данных

output media — носитель для выходных данных

general - purpose — универсальный; общего назначения

stand - alone — автономный

to plug in — подключать; подсоединять

leisure activities — досуговая деятельность

Задание 2 Прочтите текст и выполните задания следующие за текстом

PERSONAL COMPUTERS

Personal computers are supposed to appear in the late 1970s. One of the first and most popular personal computers was the

Apple II, introduced in 1977 by Apple Computer. During the late 1970s and early 1980s, new models and competitive operating systems seemed to appear daily. Then, in 1981, IBM entered the fray with its first personal computer, known as the IBM PC. The IBM PC quickly became the personal computer of choice, and most other personal computer manufacturers fell by the way-side. One of the few companies to survive IBM's onslaught was Apple Computer, which is sure to remain a major player in the personal computer marketplace. In less than a decade the microcomputer has been transformed from a calculator and hobbyist's toy into a personal computer for almost everyone.


What is a personal computer? How can this device be characterized?

—First, a personal computer being microprocessor-based, its central processing unit, called a microprocessor unit, or MPU, is concentrated on a single silicon chip.

—Second, a PC has a memory and word size that are smaller than those of minicomputers and large computers. Typical word sizes are 8 or 16 bits, and main memories range in size from 16 К to 512 K.

—Third, a personal computer uses smaller, less expensive, and less powerful input, output and storage components than do large computer systems. Most often, input is by means of a keyboard, soft-copy output being displayed on a cathode-ray tube screen. Hard-copy output is produced on a low-speed character printer.

—A PC employs floppy disks as the principal online and offline storage devices and also as input and output media.

—Finally, a PC is a general-purpose, stand-alone system that can begin to work when plugged in and be moved from place to place.

Probably the most distinguishing feature of a personal computer is that it is used by an individual, usually in an interactive mode. Regardless of the purpose for which it is used, either for leisure activities in the home or for business applications in the office, we can consider it to be a personal computer.

 

Задание 3 Ответьте на вопросы, используя информацию текста

 

1. When did the first personal computer appear? 2. What was one of the first PC model? 3. What is a personal computer? 4. What are the four main characteristics of a PC? 5. What does the term "microprocessor-based" mean? 6. What are the typical word sizes of a PC? 7. How is input carried out in personal computers? 8. What principle storage devices do PC use? 9. What kind of a system is a PC? 10. What differs personal computers from large computer systems?

Задание 4 Найдите в тексте английские эквиваленты следующих словосочетаний:

 

Конкурирующая операционная система; появляться ежедневно; ввязаться в драку; лучший компьютер; остаться в стороне; выдержать конкуренцию; главный поставщик на компьютерном рынке; игрушка для любителя; микропроцессорный; цельный кристалл (микросхема) из кремния; размер слова; компоненты меньшей мощности; посредством; вывести на экран; низкоскоростной принтер с посимвольной печатью; использовать гибкие диски; приборы (не) автономного хранения данных; универсальный; автономная система; отличительная черта; интерактивный режим; независимо от цели; досуговая деятельность.

 



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