Компьютерная техника. Еремина Н.В. - 6 стр.

1.3 Text 2

     1.3.1 When you read the following text, try to recognize the words of Text 1
     and to understand new words from the context. Don't check new words in
     the dictionary until you have read the whole text. Words underlined are
     explained in the Glossary or in the List of Words

      Computers are extraordinarily simple machines conceptually. Handling or
manipulating the information that has been given to the computer in such ways as
doing calculations, adding information or making comparisons is called processing.
All computers have several characteristics in common, regardless of make or design.
Information, in the form of instructions and data, is given to the machine, after which
the machine acts on it, and a result is then returned. A common kind of general
purpose digital computer can be thought of as very like a railroad system with
stations, a control tower, tracks, switches , telegraph lines, and freight cars. The
freight cars are loaded with information and they travel through the system almost at
the speed of light. The information presented to the machine is the input; the internal
manipulative operations, the processing; an the result, the output.
      These three concepts of input, processing and output occur in almost every
aspect of human life whether at work or at play. For example, in clothing
manufacturing, the input is the pieces of cut cloth, the processing is the finished
garment.


             INPUT                 COMPUTE                     OUTPUT
                                   RRR RRR



                               SEC. STORAGE
             Fig 1

     Fig.1 shows schematically the fundamental components in a computer system.
The centerpiece is called either the computer the processor, or, usually the central
processing unit. (CPU).
     The term “computer” includes those parts of hardware in which calculations and
other data manipulations are performed, and the high-speed internal memory in
which data and calculations are stored during actual execution of programs. Attached
to the CPU are the various peripheral devices such as card readers and key- boards.
When data programs need to be saved for long periods of time, they are stored on
various secondary memory devices or storage devices such as magnetic tapes or
magnetic discs.
     In the late 1950s and early 1960s when electrical computers of the kind in the
use today were being developed, they were expensive to own and run. Moreover their