AN/FSQ-7

The AN/FSQ-7 was a computer model developed and built in the 1950s by IBM in partnership with the US Air Force. Fifty-two were built and used for command and control functions for the SAGE air-defense system.

An AN/FSQ-7 computer contained 55,000 vacuum tubes, occupied about half an acre (2,000 m²) of floor space, weighed 275 tons, and used up to three megawatts of power. The fifty-two AN/FSQ-7s remain the largest computers ever built, and will likely hold that record in the future.

History

The concept was first tested on the Whirlwind I at Cambridge, Massachusetts connected to receive data from a long-range and several short-range radars set up on Cape Cod. The key breakthrough was the development of magnetic core memory that vastly improved the machine's reliability, operating speed (×2), and input speed (×4) over the original Williams tube memory of the Whirlwind I.

After Whirlwind I was completed and running, a design for a larger and faster machine to be called Whirlwind II was begun. But the design soon became too much for MIT's resources. It was decided to shelve the Whirlwind II design without building it and concentrate MIT's resources on the Whirlwind I. IBM, the prime contractor for the AN/FSQ-7 computer based the machine's design more on the stillborn Whirlwind II design than on the original Whirlwind. Thus the AN/FSQ-7 is sometimes incorrectly referred to as "Whirlwind II", even though they were not the same machine or design.

ee also

* IBM 728 magnetic tape drive

References

* Morton M. Astrahan, John F. Jacobs, "History of the Design of the SAGE Computer - The AN/FSQ/7" ("Annals of the History of Computing", Vol. 5 (No. 4), 1983, pp. 340-349)

External links

* [http://ed-thelen.org/SageIntro.html INTRODUCTION TO AN/FSQ-7 COMBAT DIRECTION CENTRAL AND AN/FSQ-8 COMBAT CONTROL CENTRAL] – Original IBM "manual" including floor plans and information flow diagrams for a SAGE installation and operation
* [http://www.radomes.org/museum/equip/fsq-7.html AN/FSQ-7 Intercept Computer] – From the Online Air Defense Radar Museum (by The Air Defense Radar Veterans' Association).
* [http://www.bitsavers.org/pdf/ibm/sage/ SAGE computer documents on Bitsavers.org]
* [http://ripsaw.cac.psu.edu/~mloewen/Q7/ The AN/FSQ-7 on TV and in the Movies]