IBM 7070 was a decimal architecture intermediate data processing system that was introduced by IBM in 1958. It was part of the IBM 700/7000 series, and was based on discrete transistors rather than the vacuum tubes of the 1950s. It was the company's first transistorized stored-program computer.
The 7070 was expected to be a common successor to at least the 650 and the 705. The 7070 was not designed to be instruction set compatible with the 650, as the latter had a second, jump address in every instruction to allow optimal use of the drum, something unnecessary and wasteful in a computer with random access core memory. As a result a simulator was needed to run old programs. The 7070 was also marketed as an IBM 705 upgrade, but failed miserably due to its incompatibilities, including an inability to fully represent the 705 character set; forcing IBM to quickly introduce the IBM 7080 as a "transistorized IBM 705" that was fully compatible.
The 7070 series stored data in a 10 decimal digit plus sign word. Digits were encoded using a two-out-of-five code. Characters were represented by a two digit code. The machine shipped with 5000 to 9,990 words of core and the CPU speed was about 27KIPS. A typical system was leased for $17,400 per month or could be purchased for $813,000.
See also 
- Trucks, sheep and the IBM 7070, IBM
- Emerson W. Pugh, Lyle R. Johnson, John H. Palmer, IBM's 360 and early 370 systems, MIT Press, 1991, ISBN 0-262-16123-0, p. 50
- Bashe, Charles J.; Johnson, Lyle R; Palmer, John H.; Pugh, Emerson W. (1986). IBM's Early Computers. MIT. p. 473. ISBN 0-262-02225-7.
- "A Quicker Computer Introduced by I.B.M.". New York Times. July 8, 1960. "IBM offers speedier 7074 computer to rent for $29,300 a month."
- The IBM 7070 Experiences of one user, Tom Van Vleck
- BIRTH OF AN UNWANTED IBM COMPUTER Computer History Vignettes By Bob Bemer
- IBM 7070 documentation on Bitsavers.org
- Dave Pitts' IBM 7090 support – Includes a cross assembler for the IBM 7070/7074
- Weik, Martin H. (March 1961). A Third Survey of Domestic Electronic Digital Computing Systems: IBM 7070 Section. Ballistic Research Laboratories (BRL). Report No. 1115. Contains about 10 pages of IBM 7070 survey detail: applications, customers, specifications, and costs.