Automatic Digital Computer M-1
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The M-1 computer was developed in 1950-1951 in the Laboratory of Electrosystems at the Institute of Energy of the USSR Academy of Science (AS USSR) under the direction of I. S. Brouk, an associate of the AS USSR. The developer team includes five graduate and pre-graduate engineers from the Radiotechnical Faculty of MEI (Moscow Institute of Energy) and three technicians (N. Ja. Matyukhin, T. M. Aleksandridi, V. V. Belynsky, A. B. Zalkind, M. A. Kartsev, Ju. V. Rogachev, R. P. Shidlovsky, L. M. Zhurkin.)
The director of the Institute of Energy, academician G. M. Krzhizhanovsky, authorized the specifications for M-1 in December, 1951. The computer was put into operation in spring, 1952, approximately at the same time as the MESM computer, developed in Kiev under the direction of academician S. A. Lebedev.
Academician S.L. Sobolev was the first user of M-1. At that time, he was the academician I. V. Kurchatov's deputy on scientific work and solved tasks related to nuclear physics, such as transposition of many-dimension matrixes and other calculus problems.
The M-1 was one of the first digital computers that stored programs in the main memory. M-1's instruction set had 2 addresses for operands. Its main memory, which held up to 512 of 25-bit numbers, consisted of a high-speed electrostatic storage device (up to 256 numbers) and a storage device on a magnetic drum (also up to 256 numbers). Fixed-point numbers were stored as binary values (24 bits for absolute value and 1 bit for the number sign).
The M-1's performance was 20 instructions per second (instructions of adding two numbers).
M-1 occupied three racks that surrounded a rectangular ventilating column. These racks contained the main program gauge (the computer control device), the arithmetic block and storage devices. Its input and output devices – a teletype and a photodetector for punched tape – were placed on a separate desktop and connected to the racks by dismountable cables. All the electronic circuits of the computer were mounted on standard panels which integrated either ten or twenty two tubes each). The total number of electronic tubes in M-1 was 730 – less than in other computers due to the implementation of semiconductor diodes in M1's logical circuits.
A four-modules aggregate unit was used as the DC source for M-1. The blocks of the electrostatic storage device and the memory blocks on the magnetic drum were powered from electronic power stabilizers.
The computer occupied the area of 9 sq. m.
Main features:
M-1 was one of the first digital computers with program stored in the main memory. The unabridged name of M-1 is Automatic Digital Computing Machine. Unlike the name Electronic Calculating Machine, which was adopted by S.A. Lebedev, it adequately expressed the essence of a computer that stored programs in its memory. By that time, the M1 developers knew nothing of the report of the Preston University, in which John von Neuman formulated his principles of system architecture.
M-1 was the first Soviet small-size computer that had logical circuits based on semiconductor diodes and featured main memory based on oscillographic electronic tubes.
M-1's instructions had 2 addresses for operands, though using 3 addresses was generally accepted at that time and considered as the most natural technique. This solution was prompted to the M-1's developers by Ju. A. Shreider, a mathematician who was mastering programming on M-1 together with its developers. He noticed that, for many formulas of approximate calculations, the result yelded by the previous instruction is used as an operand for the following one.
References:
The report on the project Automatic Digital computer [М1]. Moscow, USSR Academy of Science. Institute of Energy named in honor of G.M Krzhizhanovsky, The Laboratory of Electrosystems, 1951.
