A computer means a series of electronic computing, needs to able to receive, remember, convert and give information using computational and logical operations on a particular algorithm or program.
Historically, the largest distribution (by virtue of their benefits) were digital computers operating with a discrete (digital) information. Therefore, using the term "computer" usually involve class digital computers as the most important.
The basis of computers accounted for their technical means (TS), by which means the physical equipment involved in the automated data processing.
We know that to implement an automated data processing in a computer includes a number of central and peripheral devices, each of which performs functions quite finished, that is is functionally complete part of the technical tools (Fig. 2).
By the central are, as a rule, the following basic equipment: arithmetic logic (ALU), the central government (TSUU) and remote control and alarm systems (PUiS), forming a combined processor and the main (operational) memory, implemented in the form of rapid storage device (RAM). Shemotehnicheski central device usually a more or less homogeneous repetitive patterns and are sold mainly in electronic components (chips, transistors, etc.) in a certain constructive (electronic units).
By peripherals include external storage devices (OVC), representing the storage of information, working on different physical principles, for example, using magnetic, optical, paper and other media, as well as input devices (UVv) and withdrawal (UV) information. Nomenclature of peripheral devices used in the composition of modern computer is sufficiently broad: storage, displays, printers, keyboards, scanners, plotters, etc. Much of peripheral devices, along with electronic circuits contain electromechanical and mechanical assemblies rather complex in a constructive relation.
In conjunction with the software, procedures, documentation, support staff and other components of modern technology allows computers to create powerful computing systems for various purposes: automated data processing, management, automation design and production, education, etc.
There are currently developing two main lines of improving the productivity calculations. The first - the creation of computer mnogomashinnyh complexes, based on a computer with the same characteristics, or computers with different speed, structure and composition, but the hardware and software compatible with each other. The second area - the creation of multiple computer systems, the basis of a single computer with an expanded network of central and peripheral processors.
These circumstances require the introduction of additional new concepts.
The difference function and specificity of connecting the central and peripheral devices in the computer system can provide within its functional subsystem (part). Thus, a central computer system GOST 15971 - 84 defines as part of technical facilities, consisting of a single unified management of central processors, main memory and channels. The central portion must contain at least one central processing unit, but may contain more than one. In the latter case it is called multiprocessor.
Depending on the number of central parts of GOST 15971 - 84 distinguish between computers and computing systems. In doing so, GOST electronic computer as part of the digital computing system (representing its facilities), which includes a central portion and for data processing that is running the program in a memory. Computer trading - is a set of technical computing systems, with at least two central parts. Sometimes the computer complex seen as combining multiple computers.