Our Compatriots – Computer Pioneers. Part 2.<BR> Creator of the ternary computer | History of Computing in Ukraine

Our Compatriots – Computer Pioneers. Part 2.
Creator of the ternary computer

Creator of the ternary computer Being a senior student at the Moscow State University and working on his graduation diploma project, the future creator of the first and the only in the world ternary computer Nikolay Brusentsov (born in1925 inDneprodzerzhynsk, Ukraine) bumped into necessity to calculate the complex tables. By that time he had already got to know numerous calculating methods and composed the diffraction tables on elliptic cylinder (know as Brusentsov tables). Thus, the base for his activity in the field of computer engineering at theMoscowstate University was formed.

His scientific advisor academician S.Sobolev was interested in creating a small computer, which would have price, size and reliability good enough to use it in the institute's laboratories. In the seminars that he organized took part such scientists as M.Shura-Bura, K.Semendyaev, E.Zhogolev and, of course, S.Sobolev himself. They analyzed the disadvantages of the existing machines, discussed the commands system and structure, which is now called the architecture, examined the variants of technical realization, being inclined to magnetic elements, as transistors didn't exist at the time; they rejected vacuum tube diodes at once, choose easy accessible mandrels and semiconductor diodes and decided to do assembly by themselves. At the seminar on April 23, 1956, with S.Sobolev participation, the main technical demands to the small computer composition were formulated. M.Brusentsov was appointed the head and, at first, the only executant of the works. It should be emphasized that it was all about the machine with binary notation using magnetic elements.

At that moment M.Brusentsov got an idea to use the ternary notation. It made possible to create very simple and reliable elements and to reduce their number in the machine by factor of seven. It also reduced the demands to the capacity of power supply, to the rejection of mandrels and diodes, and above all, the opportunity appeared to use the natural number coding instead of the direct, inverse and additional codes.

In 1958 the laboratory staff (there were almost 20 of them at that time) assembled the first sample of the machine with their own hands. They were excited like children, when after 10 days of tuning the computer came out alive! It was the first case like that in the practice of the machine creators and tuners of those years. The machine was called "Setun" after the river nearby theMoscowUniversity.

The Council of Ministers of theUSSRdecreed that theKazanplant of mathematical machines would be responsible for the serial production of the "Setun" computer. Design documentation for the machine was prepared at the special design bureau of theInstituteofCyberneticsof the AS of the Ukrainian SSR. The first sample of the machine was showcased at the State exhibition inMoscow. The second one was tested at the plant, because the plant administration tried to prove that the machine, which was evaluated by the Inter-departmental commission and worked successfully at the State exhibition, wasn't good enough to be manufactured. M.Brusentsov recalls: "We had to align factory (second) sample with relevant documentation by our own hands; at the tests it had shown 98% of effective time with only one failure (a teletype diode was broken), and also a solid capacity by means of climate and voltage variations. On September 30, 1961, the director of the plant had been obliged to sign up a document that stopped his attempts to bury our machine."

The Kazanplant produced 50 "Setun" computers, 30 of them worked at the higher education establishments of the USSR.

The machine sparked the great interest abroad. The Ministry of foreign commerce had received requests from capitalistic European states, not talking about the socialistic countries. But none of them was realized, the ministry cancelled the production.

The next computer was "Setun-70", a machine, which combined the unknown at that time (1966-1968) RISC-ideas with the advantages of ternary logics, ternary code and structured programming of Edsger Dijkstra. A dialog system of structured programming was created for it that contained numerous highly efficient, reliable and compact products, such as: cross-system of microcomputer programming, elaboration systems of technical aids on the basis of mono-crystal microprocessors, text processing systems, robot-manipulators control, medical monitoring, etc.

Nowadays Nikolay Brusentsov, a veteran of the computer techniques, leads the computer laboratory at the Department of numerical analysis and cybernetics of theMoscowM.LomonosovStateUniversity. His main research interests are the digital machines architecture, automated teaching systems, programming systems for mini- and microcomputers. The computer "Setun-70" is still successfully used at theMoscowUniversity.

Author Boris Malinovsky