IBM 7070

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, with the 650's drum memory replaced with much faster core memory. The 7070 was not designed to be instruction set compatible with the 650, as the later 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 a IBM 705 upgrade, but failed miserably due to its incompatibilities, including an inability to fully represent the 705 character set; 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. Digits were encoded using a two-out-of-five 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.

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.

External links

* [http://www.multicians.org/thvv/7070.html The IBM 7070] Experiences of one user, Tom Van Vleck
* [http://web.archive.org/web/20041213053346/www.bobbemer.com/BIRTH.HTM BIRTH OF AN UNWANTED IBM COMPUTER Computer History Vignettes By Bob Bemer]
* [http://www.bitsavers.org/pdf/ibm/7070/ IBM 7070 documentation] on Bitsavers.org
* [http://www.cozx.com/~dpitts/ibm7090.html Dave Pitts' IBM 7090 support] – Includes a cross assembler for the IBM 7070/7074
*cite book
first = Martin H.
last = Weik
title = A Third Survey of Domestic Electronic Digital Computing Systems: IBM 7070 Section
publisher = Ballistic Research Laboratories (BRL)
date = March 1961
id = Report No. 1115
url = http://ed-thelen.org/comp-hist/BRL61-ibm7070.html#IBM-7070 Contains about 10 pages of IBM 7070 survey detail: applications, customers, specifications, and costs.