Many of Brook's employees went on to work in computing projects for the military. Alexander Zalkind shared with me some of his intimate knowledge of formerly top-secret projects completed at the Scientific Research Institute of Automatic Equipment. The following is an excerpt from Zalkind's account:

In 1957 we – O.V. Rosnitsky, A.I. Shurov, our leader Nikolai Matyuhin, and I – decided to move to the Research Institute of the Radio Industry Ministry to develop the Soviet version of SAGE.^[1] The Scientific Research Institute of Automated Equipment was founded in 1956. Dr. G.L. Shorin was the director and chief designer of the projected air defense system. In 1958, our group became engaged in developing the 'Earth' System.

The Earth system began with the ordinary telegraph equipment. The information about moving objects was transmitted through a telegraph network. Telegraph operators formatted the messages and delivered them to digital board operators, who coded them into discrete data; this data from the boards was passed on to the data calculation equipment to obtain the coordinates and trajectories of moving objects. The output data was kept on a magnetic drum that acted as a buffer. Then the data was transmitted from the magnetic drum to a secondary processing computer and workstation that used a special cathode ray tube. The letters, figures and logical symbols were drawn on the screen of the tube by electronic beam masking.

All of the equipment was built very fast to meet a deadline. In the second quarter of 1960, the State Commission reviewed our equipment and concluded that the system was not reliable due to the insufficient dimension-mass performance of the units employing electronic vacuum tubes. The Commission decided to prohibit the usage of electronic tubes in all future projects.

One of the reasons we mention the Earth system here is to offer some perspective on our team's subsequent successes. Within fifteen years, our institute had created a fully operational global network that included more than twenty regional switchboard centers. This network provided around-the-clock information exchange with the Air Defense System. During this period, the system was virtually failure-free. Tetiva, the first model of Soviet semiconductor computer, was conceived in 1960 for this specific purpose.^[2]

The Tetiva was the first Soviet computer that used a micro program kept in the binary storage memory matrix [in Russian: Dvoichnoe Zapominaushchee Ustroistvo, or DZU]. Later, this micro program control system was used in the Armenian Nairi computer developed in 1964, the Mir, and the ES-1020 computers. Tetiva's arithmetic unit used only direct operand codes. This kind of arithmetic unit was more expensive than anything previously developed, but it was the fastest and had the best self-controlling processor.

The Minsk Computer Factory manufactured the Tetiva series and by 1962 eight of them were placed at various national defense installations. The initial information input for Tetiva was carried out with the help of a special mechanical switch that took the objects' coordinates from a cathode ray tube screen. The computer program semi-automatically provided information about the location of the missile.

In order to guarantee the function of the air defense system around-the-clock, two Tetivas operated simultaneously to create a 'failure-free computer complex.' If a problem appeared in one computer, the system automatically switched to the other machine. This computer complex faithfully served the Soviet Air Defense for over thirty years and in 1987 caught Mathias Rust's flight into Soviet air space. The development of a Tetiva based system was still in progress when the work began on the first series of mobile variations of the computer, 5E63 and 5E63.1. In 1967, after successful tests, the computers went into mass-production. Since then, hundreds of them have been manufactured.

Also in 1967, we began to work on the first ES-compatible computer using the execution module of the 5E76. The first 5E76 was used as part of a six-computer complex.

In 1969, we started working on the 'Global-Scale' air defense control system, intended to serve the area from the Baltic Sea to the Pacific. Its main feature was a guaranteed connection through the regional message switchboard centers and constant twenty-four hour, three-hundred and sixty-five day reliability in automatic operation mode. Physical workspaces for manual operation were built into the system allowing for a "man-machine" connection if necessary, but they were intended only for auxiliary control.

Due to space limitations and reliability requirements of the switchboard center computers, we developed a dual-computer system made up of two 5E76-B computers – modernized 5E76s. This new system was called 65s180, and between 1972 and 1992, thirty-two of these had been manufactured.

All of these machines were developed under Matyuhin's management and designed by him and his colleagues solely for the Soviet air defense systems. This topic itself awaits exploration by other scholars and researchers.

^[1] Editor's Note: SAGE was the acronym for Semi-Automatic Ground Environment, the computerized air defense system designed at Massachusetts Institute of Technology.

^[2] Editor's note: In Russian, Tetiva means bowstring.