From the history of computers

1. Computer systems have been classed into three generations. The first generation consisted of vacuum-tube-based machines. They used magnetic drums for internal storage and magnetic tape for external storage. These computers were slow compared to modern machines and required data to be brought to them.

2. Second-generation computers using transistors began to appear in 1959. The internal storage used magnetic cores, with magnetic material wired into frames that were stacked into large cores. This form of storage represented a tremendous increase in speed and in bulk over previous storage methods. The external storage in second-generation computers used magnetic disks. This form of storage also added increased speed and greater "online" capability as compared to magnetic tape systems.

3. Since 1964, a third generation of computers has begun to emerge. These computers utilized integrated circuits to increase capability and decrease size, while integrated technology also provided improved internal storage capability. Solid-state memory, being now totally electronic, greatly increased the speed and capacity of the internal memory while decreasing its cost and complexity. External memory continued to use magnetic disks, which became larger and faster.

4. It was stated that early computers required data to be brought to them. This data was usually prepared by using punched cards or magnetic tape. The cards or tapes would then be carried to the computer where they would be processed. The transfer of data in this fashion was called batch processing. As each batch of data was received, it was placed into line with other batches of data which were processed one after another. Reports were generated, files were updated, new tapes were made and the revised data was routed to appropriate locations in the form of punched cards or magnetic tape. The inefficiency of such a system is easily seen in retrospect.

5. Later-model computers are provided with the capability of handling numerous input devices directly. These multitask computers treat the incoming data in much the same way as the earlier computers did. Incoming data is received from the various input devices and is lined up, or queued by the computer. The computer will then process the incoming data according to internal procedures. The modern computers are so fast in their operation that they can handle many users without the users even being aware than others are on the system.

VI. Say if the following statements are true or false. Correct the false statements.

1. An early computer used to be made of vacuum tubes.

2. The internal storage of the second-generation computers represented a great increase in speed and reduction in bulk over previous storage methods.

3. Since 1964, the third-generation computers have begun to use magnetic disks.

4. The transfer of data called batch processing is seen to be extremely efficient in retrospect.

5. Multitask computers process the incoming data in the way similar to the earlier computers.

VII. Choose the best answer: a, b or c to complete the sentences.

1. The first generation computers were designed on the basis of

a) integrated circuits;

b) vacuum valves;

c) semiconductor devices.

2. The second-generation of computers is based on

a) transistors;

b) magnetic discs;

c) superconducting devices.

3. A third generation of computers provides

a) the capability of handling numerous input devices directly;

b) improved external storage capability;

c) increase in speed and capacity of internal memory.

4. Modern computers can handle

a) magnetic cores;

b) magnetic drums;

c) input devices directly.

VIII. Divide the text into logical parts and find the topical sentences in each part.

IX. Give a short summary of the text.

Date: 2015-12-13; view: 560; Нарушение авторских прав