MESM
MESM (Russian: МЭСМ, Малая Электронно-Счетная Машина — "Small Electronic Calculating Machine") was the first universally programmable electronic computer in the Soviet Union, built between 1948 and 1951 by a team under Sergei Lebedev at the Kyiv Institute of Electrotechnology, in the suburb of Feofaniya. It is widely described as the first electronic stored-program computer in continental Europe — a claim that survives scrutiny only with care: Konrad Zuse's electromechanical Z4 (1945) and Sweden's relay-based BARK (1950) ran earlier, but MESM was the continent's first electronic machine of its kind, and the first outside Britain.[1]
A "model" that became a machine
Lebedev's group originally conceived MESM as a layout — the "M" stood for "model" — a reduced prototype to test the architectural principles planned for its big sister, the BESM ("Large Electronic Calculating Machine") being designed for Moscow. The scheme was complete by the end of 1949, and when early tests succeeded, the government demand for computing turned the prototype into a full machine "capable of solving real problems."[2]
The computer was assembled in a two-story building of a former convent hostel in Feofaniya — a building that had housed a psychiatric hospital before the war, chosen because it stood apart from the city.[3]
Chronology
| Date | Event |
|---|---|
| End 1949 | Principal architecture scheme and individual block diagrams ready |
| 1950 | Mounted in the Feofaniya convent-hostel building |
| 6 Nov 1950 | First test launch — solves Y″ + Y = 0 with boundary conditions |
| 4 Jan 1951 | First useful calculations: factorials and exponentiation; demonstrated to a commission headed by Mstislav Keldysh |
| 25 Dec 1951 | Passes official government testing; enters regular operation |
| 1957 | Transferred to Kyiv Polytechnic Institute for training |
| 1959 | Dismantled — its chassis became teaching stands that were later discarded |
The machine
| Parameter | Value |
|---|---|
| Element base | ~6,000 vacuum tubes (≈3,500 triodes, 2,500 diodes) |
| Clock | 5 kHz |
| Performance | ~3,000 ops/min; one cycle 17.6 ms; division 17.6–20.8 ms |
| Words | Fixed-point binary, 16+n bits + sign |
| Instructions | 20-bit, three-address: 4-bit opcode, 5+5-bit operand addresses, 6-bit result address; 11 instruction types (add, add-with-carry, subtract, multiply, divide, shifts, comparisons, control transfer, drum read, halt) |
| RAM | Flip-flop registers — 31 words data + 63 words program, data and code separated |
| External storage | Magnetic drum, up to 5,000 codes |
| Input | Punched cards or plug-switch entry |
| Output | Electromechanical printer or photographic device |
| Size / power | ~8–10 m × 2 m; 60 m²; 25 kW |
People and work
The team that would form the nucleus of all later Kyiv computing cut its teeth on MESM: engineers Lev Dashevsky, Zoya Rapota — often described as the USSR's first woman computer operator and programmer — Kateryna Shkabara, Solomon Pogrebinsky, Tamara Petsukh, and others. Senior researcher Kateryna Yushchenko of the Institute of Mathematics was a member of the group operating the machine — the experience that convinced her machine-code programming was inadequate and led to the Address programming language.[4]
MESM's workload was national-scale: thermonuclear-process calculations for Keldysh's group, ballistics, distribution line design for power stations, and other problems that made the machine genuinely useful rather than merely demonstrative.[5]
In 1952 Lebedev was called to Moscow to head the laboratory building BESM. His Feofaniya laboratory passed to the Institute of Mathematics — and under Boris Gnedenko, then Victor Glushkov, went on to build the Kiev computer, Dnipro computer, and the MIR computer series before becoming the Institute of Cybernetics in 1962.[6]
Legacy
MESM ran until 1957, spent two years teaching students at Kyiv Polytechnic, and was dismantled in 1959. Boris Malinovsky's recollection is blunt: "The computer was split into pieces, which were used to build a series of stands, after which all of them were thrown away." Surviving tubes and components are held by the Foundation for the History and Development of Computer Science and Technology in Kyiv's House of Scientists. The Feofaniya building still stands — at what is now Academician Lebedev Street, 19.[7]
References
- Mike Hally, Electronic Brains: Stories from the Dawn of the Computer Age (2005) — MESM chapter
- Boris Malinovsky, Pioneers of Soviet Computing — participant history
- en.wikipedia "MESM" — specs, chronology, Malinovsky quote
- Glushkov Institute museum, icfcst.kiev.ua/MUSEUM — team photographs, Lebedev biography
See also
- Kiev computer — the laboratory's second machine
- Sergei Lebedev · Victor Glushkov · Kateryna Yushchenko
- Address programming language
- Dnipro computer · MIR computer