Nikolay Brusentsov - the Creator of the Trinary Computer


On June 21, 1941, the day before the beginning of the Great Patriotic War of the USSR Nick Brusentsov was an eighth-form (equivalent to 10th grade in the USA) schoolboy living in Dnepropetrovsk. He participated in competitions of young musicians, conducting a chorus which sang his own composition about Dzerzhinsk metallurgy workers. Everything was remarkable.

However, the next morning, together with the other children who had arrived from Dneprodzerzhinsk, he was urgently sent back home. He was already home when he heard Molotov's radio speech. The words "The Victory will be ours!" and Borodin's Bogatyrskaya symphony which followed were memorable for him.

Thus ended Nikolai's childhood.

He was born on February 7, 1925 in the village of Kamenskoe (now part of Dneprodzerzhinsk), Ukraine. His father Pyotr Brusentsov - the son of a railway worker - completed his studies at a worker's institute and in 1930 graduated from Dnepropetrovsk Chemistry Institute. He participated in construction of Dneprodzerzhisk coke firing plant. He died in 1939 at the age of 37. Nikolai's mother Maria Dmitrievna worked as the supervisor of a kindergarten at the plant where her husband had worked. Young woman bravely withstood the heavy blow. Three children required care. Nick was the eldest of the brothers. The youngest was only one year old. They still hadn't recovered from Pyotr's death when the war began. The bombings started. They dug holes in the ground near the house and hid there during the bombings. The kindergarten, where Maria worked along with the coke firing plant was evacuated to the Orenburg region.

Six months later, in February 1943, at the age of 18, Nikolay was drafted into the Army and sent to radio classes in Sverdlovsk. Six months later he was sent to a rifle division. The division formed near Tula. Two weeks later they were mobilized to Nevel where our troops were semi-surrounded by Germans.

Then, the war became easier - with successful offensives in Byelorussia, the Baltic republics, and East Prussia. The young soldier, yesterday a schoolboy, was awarded with a medal "For Bravery" and the Red Star Order. Of the twenty-five 18-year old soldiers who formed the division in August 1943, only five remained. Here, on the outskirts of Konigsberg, Brusentsov greeted that day that would be bright and memorable for the rest of his life, Victory Day.

He graduated from the 10th form in 1947 with excellent marks, and on the advice of a Moscow friend, Nikolai applied to the Radio Department of the Moscow Energy Institute.

After finishing the Institute in 1953 Brusentsov was sent to a job at the SCB at Moscow University

Recollecting his first meeting with Sobolev, Nikolai Brusentsov said me:

"When I first visited Sergei Sobolev's office, it seemed me that I was illumined by sun light - so kind and open was his face. We immediately had a mutual understanding and I am grateful to destiny for leading me to this remarkable man, bright mathematician, and knowledgeable scientist, who was one of first persons understood the significance of computers."

Sobolev was inspired with the idea of constructing a small computer , suitable for use in institute laboratories due to its cost, size and reliability. He organized a seminar in which took part M.Shura-Bura, K.Semendyaev, E.Zhogolev and of course Sobolev himself. We analyzed disadvantages of existing computers, looked at instructions system and structures (nowadays called "architecture"), considered various plans for technical implementation, moving closer to the use of magnetic elements, inasmuch as transistors did not exist and we had excluded electronic tubes at that point. But, magnetic rods and diodes were available and we could do everything ourselves. At one of the seminars where Sobolev participated (April 23, 1956) the task of creating a small computer put forward, and its fundamental technical requirements were formulated. At the beginning, Brusentsov was appointed director and sole executive designer of the new computer. It should be noted that we're talking about a computer, with a binary system of calculation on magnetic elements.

It was namely then that he decided to use a trinary number system. It allowed for the creation of very simple and reliable elements and reduced their quantity by seven times as compared to the number of elements used by L.Gutenmacher. The power source requirements were sharply reduced, due to the fact far fewer magnetic cores and diodes were being used. But the main advantage was that a natural number coding system was used instead of direct, inverse and complement number coding.

He developed and assembled a circuit for a trinary adder which began to work reliably as soon as it began operating. S.Sobolev, having found out about his intention to create a computer based on a trinary scale of notation fiercely supported the project and promised to bring on some young assistants. Inventing adders, counters and other typical circuits didn't present much of a problem to Brusentsov.

In 1958 Brusentsov's team (at that time amounting about 20 persons) assembled the first model of the computer with their own hands.

And what was their fun when on tenth day of complex adjustment the computer started to operate! It was extraordinary record in computer adjustment practice of that period! They named the computer as "Setun" - by the name of river near Moscow University.

In accordance with a decision by the USSR Cabinet of Ministers, the Kazan Mathematical Machines plant was commissioned with the mass-manufacture of the "Setun" computer. The first model of the computer was demonstrated at a National Exhibition in Moscow.

Whether or not Brusentsov was right - only time will tell. On my part, I cite only one fact. In December 1993 I met the well known specialist in computer science, professor Klimenko who works for the computer center of the High Energy Physics Institute computer center (in the Moscow suburb, Protvino). The scientist had just returned from USA where he had been requested by some Americans to give a short lecture course on the history of computer science and technology in the Soviet Union. To my question what did the American listeners ask about, he answered: "For some reason, only about Brusentsov and his "Setun" computer".

In case of further interest, please, in Russian.
Mikhail A.Kartsev - Developer of Super-Computers for Space Observation