# List of vacuum-tube computers

Vacuum-tube computers, now called first-generation computers, are programmable digital computers using vacuum-tube logic circuitry. They were preceded by systems using electromechanical relays and followed by systems built from discrete transistors. Some later computers on the list had both vacuum tubes and transistors.
This list of vacuum-tube computers is sorted by date put into service:
| Computer | Date | Units | Notes |
| Arthur Halsey Dickinson (IBM) | 1939 | 1 | Not programmable, executed addition and subtraction, the first electronic output (display) |
| Joseph Desch, NCR3566 (NCR) | 1939 | 1 | Not programmable, executed addition and subtraction, thyratron decades |
| Atanasoff–Berry Computer | 1942 | 1 | Not programmable, could solve a system of linear equations |
| Colossus | 1943 | 10 | The Mark II version was the first programmable (by switches and plug panels) special-purpose (cryptanalysis) electronic digital computer. It was used in breaking the German Lorenz cipher; and superseded the Heath Robinson (codebreaking machine). A working replica is demonstrated at The National Museum of Computing, Bletchley Park. |
| ENIAC | 1945 | 1 | First large-scale general-purpose programmable electronic digital computer. Built by the University of Pennsylvania's Moore School of Electrical Engineering for the U.S. Army's Ballistic Research Laboratory. Originally programmed by wiring together components, by April 1948 it had been converted to a form of stored-program operation. It was decimal in nature, not binary. |
| Manchester Baby | 1948 | 1 | First electronic stored-program computer, worked June 1948; prototype for the Mark 1. Working replica demonstrated daily in Manchester Museum of Science and Industry |
| Manchester Mark 1 | 1949 | 1 | Provided a computing service from April 1949. First index registers. Re-engineered 1951 as Ferranti Mark 1. |
| EDSAC | 1949 | 1 | First ran on 6 May 1949, and provided a computing service for Cambridge University until 1958. Working replica being built at The National Museum of Computing, Bletchley Park. |
| BINAC | 1949 | 1 | First stored-program computer to be sold, but did not work for customer. |
| CSIRAC | 1949 | 1 | Oldest surviving complete first-generation electronic computer — unrestored and non-functional. |
| SEAC | 1950 | 1 | First U.S. stored-program computer to become operational. Built by and for the U.S. National Bureau of Standards. Used solid-state diode circuits for its logic. Several computers were based on the SEAC design. |
| SWAC | 1950 | 1 | Built for the U.S.'s National Bureau of Standards, it had 2,300 vacuum tubes. It had 256 words (each 37 bits) of memory, using Williams tubes |
| ERA Atlas | 1950 | | (Military version of Univac 1101) Used 2,700 vacuum tubes for its logic circuits |
| MADDIDA | 1950 | 6 | Special-purpose digital computer for solving a system of differential equations. Forty-four integrators were implemented using a magnetic drum with six storage tracks. The interconnections of the integrators were specified by writing an appropriate pattern of bits onto one of the tracks. |
| Pilot ACE | 1950 | 1 | Based on a full-scale design by Alan Turing |
| Elliott 152 | 1950 | 1 | Naval fire control computer, real-time control system, fixed program |
| Elliott 153 | 1950 | 1 | GCHQ radio signal directional finding computer, based on the Elliott 152 with programs stored on a magnetic disk |
| Harvard Mark III | 1951 | 1 | It used 5,000 vacuum tubes and 1,500 crystal diodes |
| Ferranti Mark 1 | 1951 | 9 | First commercially available computer, based on Manchester Mark 1. |
| EDVAC | 1951 | 1 | The successor to ENIAC, and also built by the University of Pennsylvania's Moore School of Electrical Engineering for the U.S. Army's Ballistic Research Laboratory. One of the first stored-program computers to be designed, but its entry into service was delayed. EDVAC's design influenced a number of other computers. |
| Harwell Dekatron Computer (The "WITCH") | 1951 | 1 | Now officially the oldest original working computer in the world. Is frequently demonstrated at The National Museum of Computing, Bletchley Park. |
| Whirlwind | 1951 | 1 | Parallel logic, approx 5,000 vacuum tubes. First use of magnetic-core memory. |
| UNIVAC I | 1951 | 46 | Mass-produced. 46 were made. |
| LEO I | 1951 | 1 | First computer for commercial applications. Built by J. Lyons and Co. restaurant and bakery chain. Based on EDSAC design. |
| UNIVAC 1101 | 1951 | | Designed by ERA, Used 2,700 vacuum tubes for its logic circuits |
| Hollerith Electronic Computer (HEC) | 1951 | | Initial design by Andrew Donald Booth, then engineered by British Tabulating Machine Company. HEC 1 can be seen at The National Museum of Computing, Bletchley Park. |
| IAS machine | 1951 | 1 | Built at the Institute for Advanced Study (IAS), sometimes called the von Neumann machine, since design was described by John von Neumann (the Von Neumann architecture). 1,500 tubes. It was the basis of about 15 other computers. |
| MESM | 1951 | 1 | First universally programmable computer in USSR, built near Kiev, used 6,000 vacuum tubes. Designed basically near to Von Neumann architecture but had two separate banks of memory - one for programs and another for data |
| Remington Rand 409 | 1952 | ~1,000 | Built by Remington Rand, it was a punched card calculator programmed by a plugboard |
| Harvard Mark IV | 1952 | 1 | Built by Harvard University under the supervision of Howard Aiken for the United States Air Force |
| G1 | 1952 | | Built by the Max Planck Institute for Physics in Göttingen, esp. by Heinz Billing |
| ORDVAC | 1952 | 1 | Built by the University of Illinois for the Ballistic Research Laboratory and was a twin of the ILLIAC I |
| ILLIAC I | 1952 | 1 | Built by the University of Illinois in Urbana |
| MANIAC I | 1952 | 1 | Built at Los Alamos Scientific Laboratory and based on the IAS computer |
| IBM 701 | 1952 | 19 | Built by IBM, also known as the Defense Calculator, based on the IAS computer |
| BESM-1 | 1952 | 1 | Built in the Soviet Union |
| Bull Gamma 3 | 1952 | ~1,200 | Made by Compagnie des Machines Bull, one of the first mass produced electronic digital computers |
| TREAC | 1953 | 1 | Telecommunications Research Establishment Automatic Computer - Parallel computer developed at TRE Malvern, England |
| AVIDAC | 1953 | 1 | Based on the IAS computer |
| FLAC | 1953 | 3 | Design based on SEAC. Located at Patrick Air Force Base. |
| JOHNNIAC | 1953 | 1 | Built by the RAND Corporation, based on the IAS computer |
| MIDAC | 1953 | 1 | Built at the University of Michigan, the first at a university in the Midwest |
| IBM 702 | 1953 | 14 | Built by IBM for business computing |
| UNIVAC 1103 | 1953 | | Designed by Engineering Research Associates (ERA) |
| RAYDAC | 1953 | 1 | Built by Raytheon for Naval Air Missile Test Center |
| Strela computer | 1953 | 7 | Built in the Soviet Union |
| ARRA II | 1953 | 2 | First Dutch computer, built at MC (now CWI) in Amsterdam. FERTA was a copy built for Fokker. |
| Datatron | 1954 | ~120 | Scientific/commercial computer built by ElectroData Corporation |
| IBM 650 | 1954 | ~2,000 | The world's first mass-produced computer |
| IBM 704 | 1954 | 123 | The first mass-produced computer with floating-point arithmetic hardware for scientific use |
| IBM 705 | 1954 | | Mostly compatible with the IBM 702, for business use. There is one that is not in operating condition at Computermuseum München. |
| BESK | 1954 | 1 | Sweden's first computer and was the fastest computer in the world for a brief time |
| IBM NORC | 1954 | 1 | Built by IBM for the US Navy Bureau of Ordnance, it was the first supercomputer and the most powerful computer in the world for at least 2 years. 9,800 tubes in logic. |
| UNIVAC 1102 | 1954 | 3 | A variation of the UNIVAC 1101 built for the US Air Force |
| DYSEAC | 1954 | 1 | Built by the U.S. National Bureau of Standards as an improved version of SEAC. Mounted in a trailer van, making it the first computer to be transportable. |
| WISC | 1954 | 1 | Built by the University of Wisconsin–Madison |
| REAC 400 (C-400) | 1955 | | In 1961 REAC installed for $60,000 at University of Minnesota. General-purpose electronic analog computer. |
| CAB 2000 | 1955 | 4 | First computer series from the French Société d'Electronique et d'Automatisme produced in several units. |
| CALDIC | 1955 | 1 | Designed to be inexpensive and simple to use; it used decimal arithmetic |
| MOSAIC | 1955 | 1 | Second implementation of ACE (Automatic Computing Engine) architecture after Pilot ACE. |
| English Electric DEUCE | 1955 | 31 | Commercial version of Pilot ACE |
| Zuse Z22 | 1955 | 55 | An early commercial computer. |
| ERMETH | 1955 | | Built by Eduard Stiefel, Heinz Rutishauser, Ambros Speiser at the ETH Zurich |
| HEC 4 (ICT 1200 series) | 1955 | | Built by Andrew Booth |
| WEIZAC | 1955 | 1 | Built by the Weizmann Institute of Science (Israel) under the guidance of Prof. G. Estrin. First computer designed in the Middle East. |
| G2 | 1955 | | Built by the Max Planck Institute for Physics in Göttingen, esp. by Heinz Billing |
| Axel Wenner-Gren ALWAC III-E | 1955 | | Commercially constructed and installed (in 1957) at University of British Columbia and Oregon State University (then College) |
| IBM 305 RAMAC | 1956 | >1,000 | The first commercial computer to use a moving-head hard-disk drive for secondary storage |
| PERM | 1956 | 1 | Built in Munich |
| D1 | 1956 | | Built by Joachim Lehmann at the TU Dresden |
| SMIL | 1956 | 1 | Built in Sweden and based on the IAS computer |
| Bendix G-15 | 1956 | >400 | A small computer for scientific and industrial purposes by the Bendix Corporation. It had a total of about 450 tubes (mostly dual triodes) and 300 germanium diodes. |
| TIFR Pilot Machine | 1956 | | TIFRAC (Tata Institute of Fundamental Research Automatic Calculator) was the first computer developed in India, at the Tata Institute of Fundamental Research in Mumbai. |
| LGP-30 | 1956 | ~500 | Data-processing system made by Librascope; bit-serial drum machine with only 113 tubes, along with 1450 diodes |
| UNIVAC 1103A | 1956 | | First computer to have hardware interrupts |
| FUJIC | 1956 | 1 | The first electronic computer in Japan, designed to perform calculations for lens design by Fuji |
| Ferranti Pegasus | 1956 | 38 | Vacuum tube computer with magnetostrictive delay line memory intended for office usage. Second oldest surviving computer in the world. |
| SILLIAC | 1956 | 1 | Built at the University of Sydney, based on the ILLIAC and ORDVAC |
| RCA BIZMAC | 1956 | 6 | RCA's first commercial computer, it contained 25,000 tubes |
| Ural series | 1956–1964 | | Ural-1 to Ural-4. |
| Elliott 405 | 1956 | 32 | Elliott's first commercial/business machine. Marketed as National-Elliott 405 |
| BESM-2 | 1957 | >20 | Built in the Soviet Union. General purpose computer in the BESM series |
| CAB 3000 | 1957 | 4 | Successor to the CAB 2000 series from the French SEA company. Had a parallel ALU for faster speed. |
| CIFA-1 | 1957 | 4 | First computer built in Romania at Institutul de Fizică Atomică (Atomic Physics Institute) |
| DASK | 1957 | 1 | The first computer in Denmark; had an early implementation of ALGOL |
| UNIVAC 1104 | 1957 | | A 30-bit variation of the UNIVAC 1103 |
| Ferranti Mercury | 1957 | 19 | An early commercial vacuum tube computer by Ferranti, with core memory and hardware floating point capability |
| IBM 610 | 1957 | 180 | A small computer designed to be used by one person with limited experience |
| FACIT EDB 2 | 1957 | 9 | |
| LEO II | 1957 | 11 | Commercial version of LEO I prototype. |
| MANIAC II | 1957 | 1 | Built by the University of California and the Los Alamos Scientific Laboratory |
| MISTIC | 1957 | 1 | A Michigan State University based on the ILLIAC I |
| MUSASINO-1 | 1957 | 1 | A Japanese computer based on the ILLIAC I |
| MMIF | 1957 | | MMIF or Machine mathématique IRSIA-FNRS, devised by a team funded by the Belgian public institutions IRSIA and FNRS, and build at the Bell Telephone Mfg Co in Antwerp, from 1952. In use 1957–1958 in Antwerp, 1958–1959 in Brussels. |
| Sandia RAYPAC (Ray Path Analog Computer) | 1957 | | Sandia's Blast Prediction Unit used for Operation Teapot |
| EDSAC 2 | 1958 | 1 | First computer to have a microprogrammed control unit and a bit-slice hardware architecture. |
| IBM 709 | 1958 | | An improved version of the IBM 704 |
| UNIVAC II | 1958 | | An improved, fully compatible version of the UNIVAC I |
| UNIVAC 1105 | 1958 | 3 | A follow-up to the UNIVAC 1103 scientific computer |
| AN/FSQ-7 | 1958 | | Largest vacuum tube computer ever built. 52 were built for Project SAGE. |
| ZEBRA | 1958 | 55 | Designed in Holland and built by Britain's Standard Telephones and Cables |
| Ferranti Perseus | 1959 | 2 | |
| Rice Institute Computer | 1959 | 1 | Operational 1959-1971, 54-bit tagged architecture |
| Burroughs 220 | 1959 | ~50 | Scientific/commercial computer, successor to ElectroData Datatron |
| Cyclone | 1959 | 1 | IAS-type computer at Iowa State College |
| DERA | 1959 | 1 | Built by Alwin Walther at the Technical University of Darmstadt; first operative in 1957, development completed in 1959 |
| D2 | 1959 | | Built by Joachim Lehmann at the TU Dresden |
| TIFRAC | 1960 | | The first computer developed in India |
| CER-10 | 1960 | | The first computer developed in Yugoslavia, it also used some transistors |
| Philips PASCAL / STEVIN | 1960 | | Philips Automatic Sequence Calculator; 1,200 valves, 10,000 transistors, and 15,000 germanium diodes. PASCAL and STEVIN (Dutch: Snel Tel En Vermenigvuldig INstrument, lit. 'Fast Count and Multiply Instrument') are identical, except input-output equipment. Both were used internally. |
| The Wegematic 1000 | 1960 | | Improved version of the ALWAC III-E |
| ZRA 1 | 1960 | | Built by VEB Carl Zeiss, Jena, German Democratic Republic |
| Minsk-1 | 1960 | | Built in Minsk, Soviet Union |
| Odra 1001 | 1960 | | First computer built by Elwro, Wroclaw, Poland |
| G3 | 1961 | | Built by the Max Planck Institute for Physics in Göttingen, esp. by Heinz Billing |
| Sumlock ANITA calculator | 1961 | <10,000/year | Desktop calculator |
| UMC-1 | 1962 | | Developed in Poland, it used the unusual negabinary number system internally |
| BRLESC | 1962 | 1 | 1,727 tubes and 853 transistors |
| OSAGE | 1963 | 1 | Close copy of the Rice Institute Computer built at the University of Oklahoma |