IBM 7090

IBM 7090
Manufacturer:	International Business Machines
Year Announced:	December, 1958
Year First Shipped:	November, 1959
Year Discontinued:	July, 1969
Form Factor:	mainframe
Word Size:	36 bits
Logic Type:	SMS cards using alloy-junction transistors
Clock Speed:	4.4 µsec (basic add instruction)
Memory Speed:	2.2 µsec
Physical Address Size:	15 bits (32K words)
Operating System:	SOS, IBSYS, IBJOB, FMS, CTSS
Predecessor(s):	IBM 709
Successor(s):	IBM 7094
Price:	US$2.9M (and up)

The IBM 7090 was IBM's first commercial transistor scientific mainframe (built at a time when computers for scientific and business computing used separate instruction sets).

It was upwardly compatible with its vacuum tube technology predecessor, the IBM 709. It had a performance of six times that of a 709, but only cost one third more.

It was designed hurriedly to meet the requirements of Sylvania, the data processing subcontractor for the BMEWS missile warning radar network, which was under a mandate to use transistor computers.

For this reason, it relied heavily on engineering from the STRETCH project; units such as power supplies, back panels and the memory unit were transplanted from STRETCH.

In addition to its use for the ground-breaking CTSS operating system, a pair of 7090's were used in the equally influential American Airlines SABRE real-time airline reservation system.

Further reading

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

External links

• 7090 Data Processing System - IBM Archive page
• From the IBM 704 to the IBM 7094
• IBM 7090/94 Architecture