The design of computers can provide, in general, as a product, is a system different in nature from different parts of the physical properties and forms, some way united among themselves mechanically and electrically, to perform certain functions with the necessary accuracy and reliability in the face of external influences.
The details included in the design of computers, either in the design of its main parts can be divided into two main groups. Varying functions.
The first group of parts formed elektroradioizdeliya; set last element can be considered a base computer. It is these elektroradioizdeliya in the construction of computers connected electrically in accordance with the conceptual framework and perform useful functions necessary transformation signals.
The second group of components within a design is in some sense secondary importance. It is intended primarily to ensure the efficiency elektroradioizdely: mechanical retention, protection from external destabilizing influences, the withdrawal of heat, etc. This group of parts which are interconnected by a mechanical and performing normally support functions, you can take a constructive basis.
It should, however, indicate that some parts consisting of these products often perform simultaneously both core and support functions. Such products could include, for example, printed circuit boards, connectors, etc. razemnye In addition, the composition of elektroradioizdely usually readily available parts, performing the typical functions of structural elements, such as: the base and cover integrated circuits (IMS), the blade to consolidate beskorpusnyh crystals IMS, etc.
The relative conventionality fission products (assembly units, details) as belonging to an element of constructive basis leads to a lack of clear criteria by which those or other primary computer design can be attributed to a specific group. In some cases, the basis for such a division could be on the organizational - manufacturing principle of assembly design. According to this principle component elektroradioizdeliya included in the list of elements of the electric scheme in principle, can be attributed to the elemental basis.
Element base are divided into groups of products:
- IMS varying degrees of integration and mikrosborki;
- Semiconductors (transistors, diodes, etc.);
- Electric products (cathode-ray tube, electric signal lights, placards, etc.);
- Elektroradioelementy (ERE) (discrete resistors, capacitors), namotochnye products (transformers, throttles, electromagnetic delay line, etc.), etc.;
- Electric and automation products (sensors, switches, etc.);
- Test equipment;
- Switching products (connectors, switches, etc.).
The remaining set of mechanical design for strength and protection from destabilizing external shocks, external appearance and internal layout, as well as motor management computer may be a constructive basis.
The basis of a constructive framework constitute the structural and individual assembly parts. Bearing structures are designed for mechanical retention, protection from external influences and access to elektroradioizdeliyam in the manufacture and operation of computers. These include boards, panels, frames, racks, frames, etc. By the constructive base also includes various executive mechanisms for the mechanical movement of media, causing the information to media, etc. Such arrangements are commonly used in the construction of computer peripherals.
The widespread introduction of computers in various areas of economy and science raises the need for continuous development and improvement of their software or technology.
In the development of computer technology since its inception accepted conditionally allocate several stages, or generations. By the characteristic features in a close relationship and determining that no other generation of computers, typically include: base element, and especially construction, architecture and logical structure, software, methods of communication users' computers, techno-economic indicators, etc. The most important is the first sign Because the element base and the construction of not only the techno-economic performance of individual devices, but also the possibility of computational process of building and development of computers in general. Progress on the components and design is always a matter of speeding up the development of computers. Particularly, it affects the functional capability of computer, productivity, computers and, of course, the reliability, size, mass and energy.
Thus, used in computers first generation element base (lamps, digital ERE, electromagnetic relays Steps seekers, switches, ferrite cell memory, etc.) and melkoblochnye construction of cells will create a sufficiently simple to modern notions of computers. For example, most first-generation high-speed computers ENIAK (USA, 1943), performed about 5000 operations of addition of a second and saved only 20 desyatirazryadnyh words containing about 18 thousand electron tubes and in need of an auxiliary refrigeration unit. This computer weighed about 30 tons and was installing more than 200 m2.
The replacement of electron tubes transistors, the use of printed mounting in the second generation of computers has meant that along with improved performance reliability, tehnologichnosti, massogabaritnyh characteristics of computers significantly improve their operational capacity and productivity, increased use of peripheral equipment.
With the development of microelectronics in the early 60-ies of the computers were new and improved element base, which is based at IMS. Their use in combination with multi-print installation created the third generation of computers with performance exceeding by several orders of the relevant characteristics of the second generation of computers. In particular, dramatically increased performance and reliability of computers because the reallocation of the electrical connections and carry out their part in some of the IMS, to simplify tuning computers, improve the accuracy of information processing, decreased size and power consumption. Improving IMS has created sophisticated computers and systems, the number of electronic equipment in which dozens of times was more than the number of equipment used in the second generation of machines.
Further development of IMS technology, methods aided design led to the creation of large crystals (BIS), extreme (VLSI) and ultra-IMS, in which the packing density reached 106 components in 1 cm3, and the level of integration - about 105 ... 107 components in the crystal. It is expected that in coming years, the degree of integration of LSI Logic will reach 107 ... 108 or more logical elements in the crystal. Such integrated circuits have to perform the functions of entire blocks of computer devices and third generation
The implementation of the functional circuits computer hull and beskorpusnyh IMS and BIS, as the matrix, and the microprocessor, currently led to the creation of a fourth-generation design. At this stage, the use of BIS significantly improve the performance of computers, increase density and, importantly, reduce labor and material costs of production. However, there was a need to address imbalances between the capacity and size of BIS, on the one hand, and the rest of elemental and meaningful base computer on the other.