IBM 704

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IBM 704
Manufacturer: International Business Machines
Year Announced: May, 1954
Year Discontinued: April, 1960
Form Factor: mainframe
Word Size: 36 bits
Logic Type: vacuum tubes
Clock Speed: 24 μsec (basic add instruction)

240 μsec (basic multiply instruction)

Memory Speed: 12 μsec
Predecessor(s): IBM 701
Successor(s): IBM 709


The IBM 704 was IBM's first commercially successful vacuum tube scientific mainframe (built at a time when computers for scientific and business computing used separate instruction sets). It was announced in May, 1954; 136 were sold.

The major advances over its predecessor, the IBM 701, included core memory, instead of the Williams tubes previously used for main memory in the 701; and support for floating point in hardware (supposedly the first mass-produced machine to do so).

The instruction set of the 704 was not compatible with the 701; the later IBM 709, IBM 7090, and IBM 7094 did use an upwardly-compatible instruction set, so the 704 founded a major family.

FORTRAN was produced for, and first implemented on, this computer. LISP was also first done on the 704.

Further reading

  • Charles J. Bashe, Lyle R. Johnson, John H. Palmer, Emerson W. Pugh, IBM's Early Computers, MIT Press, Cambridge, 1986

External links