After the work on the tube computers BESM-2 and M-20 was finished, the design work of the semiconductor computer, BESM-6, began. BESM-6 was a real masterpiece made by the scientific group of the AS-USSR AS ITM and VT, the first second-generation supercomputer. Great assistance was rendered to S.A. Lebedev - chief designer of BESM-6 - by two of his pupils who by that time became his operations manager and famous young scientists in their own right. They were V.A. Melnikov and L.N. Koroliov.

The experience of scientists from abroad in designing of high-speed computers was learned and analyzed in detail. Everything that corresponded to the aims set during the development of the machine was adopted. Lebedev initiated and took an active hand of in the mathematical modeling of the future machine. On the basis of an appointed set of problems, the range of units, their internal links, and a system of commands were defined; and semiconductor elements were worked out to the last detail.

The results of the work were: an original system of commands which made programming user-friendly, a simple, internal structure, a reliable system of elements and a design which simplified maintenance. This approach to solving complex technical problems is still valid today. It can be defined as a principle of making well-grounded decisions. Lebedev followed this principle all his life.

The BESM-6 became the first domestic computer with full software which was approved by the State Committee. Many leading specialists of the country took part in the computer's development. Lebedev was the first among those who realized the great significance of joint efforts by mathematicians and engineers in developing computer systems. The significance becomes obvious if one compares the initial development of the computer during its purely technological phase to the exponential growth in technology which took place due to joint engineering-mathematical efforts.

Finally, and quite importantly, on the initiative of S.A. Lebedev, all diagrams of BESM-6 were formulated with Boolean algebra. It opened vast horizons for automatization of design and preparation of assembly and operational documentation, tabulated on BESM-2 and given to the factory where simulation of structural diagrams was made. After that, the system design was streamlined, thanks to the work of G.G. Riabov (the "Pulse" system).

The main features of the BESM-6 were: an address-bus control system or as Lebedev called it in 1964, "plumbing". According to this control principle, the flow of commands and operands is processed in parallel (up to 8 machine commands at each stage); the use of associative memory on superspeed registers that reduced the number of retrieval calls to the ferric memory. This allowed for a localized optimization of calculation according to the dynamics: a stratification of operating memory into autonomous modules, which enabled simultaneous, multi-directional calls to memory units; a multi-program operational mode for simultaneous work on several problems with specified priorities; a hardware mechanism for transformation of mathematical addresses to physical ones, which made it possible for a dynamic distribution of the operating memory in the computational process by means of an operational system; a paged system of organizational memory which in turn developed protection mechanisms for numbers and commands; an up-to-date system interrupt which facilitated the automatic transfer from one solution of a problem to another, accessing external units and controlling their operation.

The electronic circuits of BESM-6 consisted of 60 thousand transistors and 180 thousand semiconductor-diodes. The elemental base of BESM-6 was quite new at that time and laid the foundations of circuit engineering for third and fourth-generation computers. The principle of dividing complex machine logic built on diode blocks using a single transistor amplification guaranteed a simplified manufacturing process and a reliable operation. The computer was now achieving average speeds of up to one million operations per second.

The BESM-6 prototype was launched into trial operation in 1965, and by the middle of 1967, the first manufactured model was tested. Three additional models were made at the same time, and thanks to the joint work with the manufacturer this required a shorter adjustment period to prepare the machine for serial production.

The State Committee headed by M.V. Keldish, who was President of the AS-USSR at the time, highly appreciated the computer.

On the basis of BESM-6, centers of collective use were established which facilitated real-time control systems, coordination of data teleprocessing systems, and others. The machine was used for simulating complex physical processes and control processes, and also, for development of new computer software in designing systems. The principle technical design laid out during BESM-6's development gave the computer an enviable service life: BESM-6 was produced over the course of 17 years! The computer had a good reputation among users and in the 70's, became the standard for high-speed computers.

During the Soviet-American space flight of "Apollo-Soyuz", the controls were carried out at a new computer complex which included the BESM-6 and other domestic high-speed computers which had been developed by S.A. Lebedev's pupils. Earlier, the call for telemetry data processing might have taken roughly half an hour. Now, using the new complex, the work was performed in a minute. All data processing was done by Soviet scientists, half an hour earlier than their American colleagues.

That was a real triumph of S.A. Lebedev, his pupils and school which had developed a first-class computer, capable of competing with the world's best computers! The chief designers of BESM-6 (S.A. Lebedev, V.A. Melnikov, L.N. Koroliov, L.A. Zak, V.N. Laut, A.A. Sokolov, V.I. Smirnov, A.N. Tomilin and M.V. Tiapkin) won the State Prize.

When this book was being written, I came across the work of the German philosopher Nietzsche. One of his statements drew my special attention: "The ability to show the way is a sign of genius. "Immediately, I recalled S.A. Lebedev who established the main trends and prospects for computer development. Sergei Alexeevich's pupils, L.N. Koroliov and V.A. Melnikov, in the article "About the BESM-6 computer" described the scientist in a more definite way: "S.A. Lebedev's genius was his ability to set goals, taking into account the prospects for development of the future machine structure. He could correctly choose the means for its realization, in the context of the capacity of the national industry." (Control Systems and Machines. 1976, #6).