IBM 7070
Encyclopedia
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 transistor
s rather than the vacuum tube
s of the 1950s. It was the company's first transistorized stored-program computer.Emerson W. Pugh, Lyle R. Johnson, John H. Palmer, IBM's 360 and early 370 systems, MIT Press, 1991, ISBN 0262161230, p. 50
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 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 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.
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
in June 1960. It was part of the IBM 700/7000 series
IBM 700/7000 series
The IBM 700/7000 series was a series of large-scale computer systems made by IBM through the 1950s and early 1960s. The series included several different, incompatible processor architectures. The 700s used vacuum tube logic and were made obsolete by the introduction of the transistorized 7000s...
, and was based on discrete transistor
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
s rather than the vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
s of the 1950s. It was the company's first transistorized stored-program computer.Emerson W. Pugh, Lyle R. Johnson, John H. Palmer, IBM's 360 and early 370 systems, MIT Press, 1991, ISBN 0262161230, p. 50
The 7070 was designed to provide a "transistorized IBM 650
IBM 650
The IBM 650 was one of IBM’s early computers, and the world’s first mass-produced computer. It was announced in 1953, and over 2000 systems were produced between the first shipment in 1954 and its final manufacture in 1962...
" upgrade path, with the 650's drum memory
Drum memory
Drum memory is a magnetic data storage device and was an early form of computer memory widely used in the 1950s and into the 1960s, invented by Gustav Tauschek in 1932 in Austria....
replaced with much faster core memory. 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 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
IBM 7080
The IBM 7080 was a variable word length BCD transistor computer in the IBM 700/7000 series commercial architecture line, introduced in August 1961, that provided an upgrade path from the vacuum tube IBM 705 computer....
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
Two-out-of-five code
In telecommunication, a two-out-of-five code is an m of n code that provides exactly ten possible combinations, and thus is popular for representing decimal digits using five bits...
. 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
System/360
The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...
, announced in 1964.
External links
- The IBM 7070 Experiences of one user, Tom Van VleckTom van Vleck-Life and work:He worked on CTSS at MIT, and co-authored its first email program.In 1965, he joined Project Mac, which is the origin of the MIT Computer Science and Artificial Intelligence Laboratory., Chiou, Stefanie; et. al...
- 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 Contains about 10 pages of IBM 7070 survey detail: applications, customers, specifications, and costs.