IBM 7070 was a Decimal Architecture intermediate data processing system that was introduced by IBM in June 1960. It was part of the IBM 700/7000 series, and was based on discrete transistors rather than the vacuum tubes of the 1950s.

The 7070 was designed to provide a "transistorized IBM 650" upgrade path. They replaced the drum memory with core memory, but were not instruction set compatible with the 650. As a result a simulator was needed to run old programs. The 7070 was also marketed as a IBM 705 upgrade, but failed miserably due to its incompatibilities; forcing IBM to quickly design the IBM 7080 as a "transistorized IBM 705" that was fully compatible.

The data used a 10 decimal digit plus sign word length. The digital encoding was a two-out-of-five code. The machine shipped with 10,000 words of core and the CPU speed was about 27KIPS.

Later systems in this series were the IBM 7072 introduced in November 1962 and the IBM 7074 in November 1961. They were eventually replaced by the System/360, announced in 1964.

IBM hardware

External links

• The IBM 7070 Experiences of one user.
• IBM 7070 documentation on Bitsavers.org
• IBM 7070 Data Processing System