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Family of small computers "Nairy"

The high level of mathematical school, presence of highly skilled designers and technologists, the developed industrial base in Armenia in the middle of 50-s' years of the last century predetermined the decision of the government of the USSR to create the Institute of mathematical machines in Yerevan.

The primary goals of institute were researches, design development in the field of creation of domesticcomputers; and construction, on their basis, of the automated control systems to use in the design, research and industrial organizations, engaged in processing of the information and in solving of different managerial problems.

The first director of institute was one of the most outstanding mathematicians of Soviet Union, academician Sergey Mergeljan. In institute some functional divisions working on equipment and software means design, including their design and technological equipment were created. Divisions for manufacturing different samples of devices and units, including power supplies were generated. The created divisions were further united in pilot production, and later in Experimental plant ÅrNIIMM.

          In the beginning of 60th years of the last century the post of the institute director was occupied by Faddej Tachatovich Sarkisyan, the present president of National academy of the Armenia Republic, under his initiative some large scientifical, technical, industrial and organizational problemswere put and solved. In the institute directions on the creation of small computers of family " Nairy ", of some models of a united series of universal computers (EU of the computers), and also a science-thematic center on designing the automated control systems (M.I.S.) of special purpose were generated. The course for a large-lot production of means of computer facilities, both at factories of Armenia, and at the enterprises of other republics of the USSR was set.

The development of the first model of machines of family " Nairy " was being carried out during 1962-1964 ã.ã. (the head designer was G.E.Ovsepjan).

Essentially new scheme-technical decisions, the developed of the software, focused on the solving of technical problems arising in during engineering practice, allowed to generate, on one hand, the basic architecture of all family of the small computers " Nairy ", which existed up to the beginning of the 20th centuries, and on the other hand, to create one of the most widespread small computers in the USSR, which was widely applied in scientific research institutes of the industry and higher educational institutions of the country.


The developed of computer architecture of " Nairy " was patented in England, Japan, France, Italy.

Let's consider some of the patented decisions.

For the first time for a class of small computers in the beginning of the 60th in the last century 36-digit architecture of the processor was offered. Aiming at the minimization of hardware expenses, the arithmetic device consisted only of one hardware 36-digit universal register - the adder. As other registers it was offered to use a group of the fixed cells of an operative machine memory. For each fixed cell some certain microoperations of reading and storing that provided independence of a cycle of all-operative memory and sharp increase in speed were determined.

Basic feature of offered architecture of the computer was use of a constant long-term memory of the cassette type used in two purposes:

- The organizations of memory of microprograms;

- Memories to store the built-in applied technological software of the computer.

The volume of each cartridge was 2048 36 digit words. Necessary word length of microcommands (72 categories) was provided by simultaneous reading the information from two cartridges. Other volume DZU (14 thousand 36 - digit words) was allocated to store some compilers from languages of type "Assembler" and "BASIC", software packages of the differential equations solutions, all spectrum of problems of linear algebra, programs of the direct account of various arithmetic expressions in a dialogue mode, programs of management of a typewriter and punched tape input/output, construction of schedules and diagrams, and also a complex of technological programs to check all units both at the production phases, and while computer is operating.

           Time characteristics of DZU (a cycle of reading is 8 microseconds) allowed to fulfill the whole spectrum of the considered problems with time characteristics, at least, one level better, than in foreign small computers (in which as stores of the software, memories mechanisms of type called « a magnetic drum » were used.

The large-lot production of computer " Nairy" was organized from the end of 1964 at two factories in Armenia, and also on one of the largest factories of the USSR - the Kazan computer factory.

Most brightly distinctive features of the first model of family "Nairy" were shown at anniversary Leipzig fair in the spring 1965

At this fair a great number of small computers of different firms and countries (England - firm ICL, France - firm Bull, German - firm Zuse, etc.) were shown. Computer "Nairy" was the unique microprogram computer with the expanded digit grid (36 categories), providing the high efficiency, the high accuracy of calculations (other computers had digit grids of 8,16 categories).

The Speed of computer "Nairy" was out of competition, considering the fact, that in computer "Nairy" the software was placed in constant memory with a cycle of sample 8 microseconds, and in other computers the program were stored in external memories of type «a magnetic drum ».

             The next model of family "Nairy" was “Nairy-2”, created in 1966. The basic features of this computer were the increased capacity of operative memory, use of more productive devices of input-output and the improved constructive decisions.

Comparing computer "Nairy" and “Nairy-2” with athepresent level of computer facilities we can note, that the specified computers are basically comparable in the characteristics (except for volumetric characteristics), including so-called «friendly interface of the user» with personal computers of architecture IBM PC, constructed on microprocessors Intel of the series 486, which was serially let out of 20 years after.

The developers of computer "Nairy" received five copyright certificates, including on the invention, allowing to spend performance of logic operations "and", "or" it is direct in operative memory, its fixed cells, without what or references to the arithmetic device.

Creation in the beginning of the seventieth years of the last century of a series of computer “Nairy”family (« Nairy 3-1 », « Nairy3 - 2 », « Nairy 3-3 ») was dictated by an imperative need of system use of the computer in the various automated control systems (multiterminal systems of collective using, systems of automated management by manufacture of the radio-electronic equipment, etc.).

Significant expansion of an application area of series «Nairy-3» demanded revision of the certain components of architecture of the computer. Transition from area of the engineering problems solutions to the area of control systems increase the reliability of the processing information, realization of multiterminal access to sources of the information in a mode close to real time demanded significant expansion of the computer architecture, opportunities of a computer language, revision of system of input-output of the information, transition to multimachine structures.

Thus there was a task of maximal use of the software, existing during this time period, including the packages of the applied programs, developed for other computers and being widely used in the automated control systems of the manufacture.

Successful realization of this task was carried out owing to the use of the whole complex the structural and schematechnical solutions approved in various models of a “Nairy-3” series and protected by many copyright certificates.

The organization of the microprogram device of the management having two-level structure was essentially new.

               The first - the bottom level represented memory of the minimal capacity in which the set of all necessary microcommands, setting all set of microoperations was stored, operating a hardware contour of the computer.

               The second level set sequence of addresses of the microcommands fulfilling the microprograms, machine commands carried out in the computer or some procedures. As the memory of microcommands addresses any types of the computer memories could be used.

The offered two-level structure of the microprogram device of management allowed to form in models of a series «Nairy-3» storehouse of practically unlimited set of microprograms. As the researches showed, in offered structure of the microprogram device of management the limiting density of packing of the microprograms, coming nearer to a theoretical limit of the minimal coding the information, was reached.

The fulfillment in the computer of a “Nairy-3”series of practically unlimited volume of microprograms allowed to use the methods of full microprogram emulation of not one, but of simultaneously some computer languages functioning simultaneously in the computer for the first time in the USSR. The choice of the computers, which are subjects of microprogram emulation, was defined by volume of the applied programs developed in the emulated computer.

             So in models of a “Nairy-3”series the computer languages "Nairy-1", “Nairy-2”, "Minsk-22" were realized. Thus not only separate commands had to undergo the emulation, but also the idioms representing some sequences of machine commands, having the certain purpose. For example, commands of management of external memory (magnetic tapes). Micro programming of an idiom allowed raising in some cases the productivity of the emulator on one, two orders.

Introduction of hardware of multiterminal access to sources information (computer "Nairy -3-2 ") allowed creating a hardware-software platform of the manufacture automated control systems.

A series of computers "Nairy-3 " found wide application in different branches of the national economy of the country.

The collective of developers of the specified series was awarded the State premium of the USSR (G.E.Ovsepjan - the main designer, F.T.Sarkisyan, G.S.Sagojan, M.A.Hachatrjan, M.R.Buniatjan, H.K.Ejlezjan, V.G.Ishin, S.A.Tumanjan, A.V.Zakirov), Premiums of Lenin Komsomol of the USSR was awarded to G.A.Oganjan, A.G.geoletsjan, E.L.Dzhandzhuljan, I.M.Ermakov, V.G.Gonchojan, L.A.Karapetjan, V.G.Azatjan, G.K.Aslanjan.

        11 master's research works were written in the result of development of three series of “Nairy”family.

The further development of family of small computers "Nairy" was embodied in creation of a series of computer "Nairy-4 " subject-oriented, basically, on special applications. The choice of architecture of a series of computer " Nairy-4 " was defined by requirements of substantial increase of productivity of calculations, connections of a wide spectrum of peripheral devices (displays, printers, the analog-digital equipment), constructions of failure-safe complexes with the built-in system of the hardware control and diagnostics with wide use of the constructive-technological base focused on work in rigid climatic conditions and mechanical influences.

At preservation of principles of the two-level organization of the microprogram device of management, a special emphasis was put on sharp increase in speed of the first step óñòðîéñòâ-stores of the microcommands, setting clock frequency of the computer. Considering small volume of this store its organization on multiplexers, and in the future on C. V. was offered.

              An example of the subject-oriented approach to the system construction was the creation of a complex of means of automatic designers’ work, technologists of a wide structure – computer "Nairy-4/ÀRÌ ".

The highest productivity in models of a series «Nairy-4» was reached in 1977 in computer " Nairy-41 " (2 million operations a second).

At the creation of the big territorially-distributed information-operating system of special purpose there was a necessity to create a failure-safe computer complex focused on use as for objects of system of the top control link of systems, and as for mass local objects of the system, being sources of the information of system and forming a contour of real time. Thus it was necessary to realize:

- Functions of highly reliable access to the big number of the liaison channels acting from different directions of system of data exchange.

- Performance of all information and logical tasks, without exception, local objects of system.

During the creation of the computer complex on the basis of the computer the following system-technical decisions, differing by patent novelty, were offered:

- Through hardware control of the processor and the universal trunk of input-output;

- Introduction of a mode of "hot switching-off” at which switching-off of interfaced devices of input-output without a stop of computer work is organized;

- Introduction of a complex of blocks of switches and communications of channels of the universal trunk of the computer in structure for construction of multimachine structures;

- Microprogram realization of all operations of computer complexity and the universal trunk;

- Introduction in structure of the computer and VK the specialized diagnostic processor, which functions are to diagnose the faulty typical elements of replacement;

             Universality of architecture of the developed computer complex compatible to one of the most distributed in the country computer SM-4, with the use of a microprogram emulation mode, allowed to realize the big class of the telecommunicational, informational and logical problems assigned to the objects of system;

Introduction of the VK diagnostic processor in the structure allowed to reduce the time of VK restoration, having increased the time of system’s readiness. Considering the mass character of local objects, the specificity of their use,connected with territorial remoteness, the offering system-technical solutions in aggregate with the special software allowed to create a system, which was functioning for more than 15 years.

           At creation of a computer "Nairy-4 " series the developers offered 15 copyright certificates, 9 masters’ and three doctors’ research works were proved.

The family of computer "Nairy" functioning for almost forty years, under the architectural, structural, technical and program characteristics was the essential contribution to the development of computer facilities of the USSR and represented the original scientific school in the field of small computer construction.

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