1. Having returned to the accumulator the results of arithmetic operations are transferred to main storage. The results of
arithmetic operations are returned to the accumulator, the storage register transferring them to main memory. The results of
arithmetic operations being returned to the accumulator, the
storage register transfer them to main memory. Being returned
to the accumulator the results of arithmetic operations are transferred to main memory.
2.When passing through a conductor free electrons form an
electric current. Free electrons passing through a conductor, an
electric current is generated. Free electrons pass through a conductor, an electric current being generated. Free electrons passing through a conductor form an electric current.
3 Instructions being obtained, the control unit causes other units to perform the necessary operations. Instructions are obtained, the control unit causes other units to perform the operations. Having obtained the instructions the control unit causes other units to perform the operations. Obtaining the instructions the control unit causes other units to perform the operations.
4. The elements having unknown properties cannot be used for experiments. The elements have unknown properties, experiments with these elements being impossible. Having unknown properties the elements cannot be used for experiments. The elements having unknown properties, experiments with them are impossible.
5. When moving in a material charged particles ( ) produce magnetic properties () of this material. Charged particles moving in a material produce magnetic properties. Charged particles moving in a material, magnetic properties of this material are produced. Charged particles move in a material, magnetic properties of the material being produced.
14. . , , .
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It is known that one of the fundamental parts of the computer is a control unit. This unit controls the computation process automatically, without man's participation. It sends signals to all other parts of the computer to specify what they must do. First of all, the control unit tells the main memory what data must be transferred to the arithmetic-logical unit and other devices. Then it enables the arithmetic-logical unit to perform the required operation. Finally, it places the obtained results in the main memory.
It is important to note that the control unit operation is determined by an algorithm of a problem solution. The algorithm is a sequence of arithmetic and logical operations. These operations must be performed on the initial data for solving the problem.
Description of an algorithm in a form acceptable by a computer is called a program. A program is a list of sequential computer instructions enabling a computer to solve a problem. In order to be acceptable by the computer instructions must be encoded into a digital form.
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In conclusion it should be pointed out that the main feature of a computer is automatic control of the problem solution process. It is based on the programmed-control principle. . .
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1. In 1960's advances in microelectronic components led to
the development of the minicomputer, followed more recently
by an even smaller microcomputer. Both have filled a need for
small but relatively flexible processing systems able to execute
comparatively simple computing functions at lower costs.
In 1971 Intel Corporation delivered the first microprocessor, the 4004. All the logic to implement the central processing unit of a tiny computer was put onto a single silicon chip less than 1/4 inch square. That design was soon followed by many others. The progress toward smaller computers is continuing, designers are working at nano-computers and pico-computers.
When the central processing unit of a computer is implemented in a single, or very small number of integrated circuits, we call it a microprocessor. When a computer includes a microprocessor as its major component, such device is called a microcomputer.
Today the hardware in data-processing machines is built out of microelectronic devices. Advances in microelectronic devices give rise to advances in data-processing machinery.
2. The computer has made it possible to mechanize much
of the information interchange and processing that constitute
the nervous system of our society.
The versatility and convenience of the microprocessor has changed the entire architecture of modern computer systems. No longer is the processing of information carried out only in the computer's central processing unit. Today there is a trend toward distributing more processing capability throughout a computer system, with various areas having small local processors for handling operations in those areas.
There are a number of advantages of distributed processing. First,.since many elements of the computer can be working on different portions of the same task, the work may be done faster. Second, if one element in the network malfunctions, its workload can be shifted to another element or shared among several elements, so that the entire work is relatively immuneto failure. Third, the network can be small enough to be contained within a single laboratory or building, or it can be spread out over a wide area.
INPUT-OUTPUT UNITS
