List of vacuum tube computers

Vacuum tube 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. Later entries in this list may have been built using transistors in addition to vacuum tubes.

This is a list of vacuum tube computers, arranged by date put into service:

Computer	Date	Notes
Atanasoff–Berry Computer	1942	Not programmable
Colossus	1943	First programmable electronic digital computer. Special purpose: cryptanalysis. Used to break the German Lorenz cipher. Working replica demonstrated daily at The National Museum of Computing, Bletchley Park.
ENIAC	1946	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, later converted to a form of stored-program operation.
Manchester SSEM ("The Baby")	1948	First stored-program computer worked June 1948. Working replica demonstrated daily in Manchester Museum of Science and Industry
EDSAC	1949	Provided a computing service from May 1949. Working replica currently being built at The National Museum of Computing, Bletchley Park. Scheduled to go live in 2016.
Manchester Mark 1	1949	Provided a computing service from April 1949. First index registers. Replaced in 1951 by Ferranti Mark 1.
BINAC	1949	First stored-program computer to be sold, but did not work for customer.
CSIRAC	1949	Oldest surviving first generation electronic computer — unrestored and non-functional.
SEAC	1950	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	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 2700 vacuum tubes for its logic circuits
MADDIDA	1950	44 integrators were implemented using a magnetic drum with 6 storage tracks. The interconnections of the integrators were specified by writing an appropriate pattern of bits onto one of the tracks.
Harvard Mark III	1950	It used 5,000 vacuum tubes and 1,500 crystal diodes
Pilot ACE	1950	Based on a full-scale design by Alan Turing
Ferranti Mark 1	1951	First commercially available computer, based on Manchester Mark 1.
EDVAC	1951	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	1951	Now officially the oldest original working computer in the world. Demonstrated daily at The National Museum of Computing, Bletchley Park.
Whirlwind	1951	Parallel logic, approx 5,000 vacuum tubes. First use of core memory.
UNIVAC I	1951	Mass produced. 46 were made.
ORDVAC	1951
LEO I	1951	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 2700 vacuum tubes for its logic circuits
Remington Rand 409	1952
Harvard Mark IV	1952
IAS machine	1952
ILLIAC I	1952
MANIAC I	1952
IBM 701	1952
BESM-1, BESM-2	1952
AVIDAC	1953	Based on the IAS computer
FLAC	1953	Design based on SEAC. Located at Patrick Air Force Base.
JOHNNIAC	1953
IBM 702	1953
UNIVAC 1103	1953	Designed by Engineering Research Associates (ERA)
RAYDAC	1953
Strela computer	1953
IBM 650	1954
IBM 704	1954
IBM 705	1954
BESK	1954
IBM NORC	1954
REAC C-400 series	1954	In 1961 REAC installed for $60,000 at University of Minnesota
UNIVAC 1102	1954
DYSEAC	1954	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
CALDIC	1955
English Electric DEUCE	1955
ICT 1200 series	1955
WEIZAC	1955	Built by the Weizmann Institute of Science (Israel) under the guidance of Prof. G. Estrin. First computer designed in the Middle East.
IBM 305 RAMAC	1956
Bull Gamma 3	1956
PERM (computer)	1956
SMIL (computer)	1956
Bendix G-15	1956
LGP-30	1956
UNIVAC 1103A	1956	First computer to have hardware interrupts
FUJIC	1956
Ferranti Pegasus	1956	Second oldest working computer in the world, at the London Science Museum.
SILLIAC	1956
RCA BIZMAC	1956
Zuse Z22	1957
DASK	1957
Stantec Zebra	1957
UNIVAC 1104	1957
Ferranti Mercury	1957
IBM 610	1957
FACIT EDB 2	1957
MANIAC II	1957
MISTIC	1957
MUSASINO-1	1957
Sandia RAYPAC (Ray Path Analog Computer)	c. 1957	Sandia's Blast Prediction Unit used for Operation Teapot
EDSAC 2	1958	First computer to have a microprogrammed control unit and a bit slice hardware architecture.
IBM 709	1958
UNIVAC II	1958
UNIVAC 1105	1958
AN/FSQ-7	1958	Largest vacuum tube computer ever built. 52 were built for Project SAGE.
Ural series	1959–1964	Ural-1 to Ural-4.
Ferranti Perseus	1958
ZEBRA	1958
France SEA CAB 303	1958
Rice Institute Computer	1959	Operational 1959-1971, 54-bit tagged architecture
TIFRAC	1960
CER-10	1960
Philips Pascal	1960
Sumlock ANITA calculator	1961	Desktop calculator
UMC-1	1962
BRLESC	1962	1727 tubes and 853 transistors
OSAGE	1963	Close copy of the Rice Institute Computer built at the University of Oklahoma

See also

• List of transistorized computers
• History of computing hardware