The IBM AN/FSQ-31 SAC Data Processing System[1] (FSQ-31, Q-31, colloq.) was a USAF command, control, and coordination system for the Cold War Strategic Air Command (SAC). IBM's Federal Systems Division[1] was the prime contractor for the AN/FSQ-31s, which were part of the TBD 465L SAC Automated Command and Control System (SACCS),[2] a "Big L" system of systems (cf. 416L SAGE & 474L BMEWS([3] which had numerous sites throughout the Continental United States: "all SAC command posts and missile Launch Control Centers"(e.g., The Notch), a communication network, etc.; and the several FSQ-31 sites including:

The FSQ-31 provided data to a site's Data Display Central[6] (DDC) "a wall display"[6] (e.g., Iconorama), and it arrived at Offutt in 1960.[7] On 20 February 1987, "SAC declared initial operational capability for the SAC Digital Network [which] upgraded the SAC Automated Command and Control system "[4]

Description

The FSQ-31 included:

  • Electronic Data Transmission Communications Central (EDTCC) at 4 "zone-of-interior headquarters bases" for EDT with "outlying" Remote Communications Centrals (e.g., routing "to RCC's, computer (DPC's), or the display devices.")[6]
  • Tape Controllers 1 and 2, connected to 16 IBM 729-V Tape Drives
  • Disk File Controller, which was a modified Tape Controller, connected to the
    • Bryant PH 2000 Disk File, which had 24 disks that were 39 inches in diameter, 125 read/write heads that were hydraulically actuated, and had a total capacity of 26 MB
  • IBM 1401, which controlled data transfers from unit-record equipment:
  • 2 IBM Selectric Typewriters, (I/O Typewriters) one of which was used for operational messages and the other for diagnostic messages and maintenance activities.

SACCS systems outside of the AN/FSQ-31 included the Subnet Communications Processor and the SACCS Software Test (SST) Facility at the Offutt command center (the backup SCP was at Barksdale AFB.)[9] SAC's QOR for the National Survivable Communications System (NSCS) was issued 13 September 1958;[10]: 175  and in September 1960 the "installation of a SAC display warning system" included 3 consoles in the Offutt command center.[10]: 218 

Initial weight: 105,650 pounds (52.8 short tons; 47.9 t).[1]

Memory

The Q-31s were equipped with four 16 kiloword memory banks. The memory bank was oil and water cooled. Also considered as part of the memory subsystem in that they were addressed via fixed reserved memory addresses, were four 48 position switch banks, in which a short program could be inserted, and a plugboard, similar to the one used in IBM unit record equipment, that had the capacity of 32 words, so longer bootstrap or diagnostic programs could be installed in plug panels which could then be inserted into the receptacle and used. This served as a primitive ROM.

External images
image icon terminal at Offutt command center
image icon SACCS comm network

References

  1. ^ a b c d Weik, Martin H. (March 1961). "Chapter II: Computing System Description". A Third Survey of Domestic Electronic Digital Computing Systems. Ballistic Research Laboratory. p. 0044 (start page). Report No. 1115. Retrieved 1 April 2014.
  2. ^ Wohlman, John (1968). "An Aid to Command and Control". Computer-Generated Map Data. Air University Review. Retrieved 20 June 2006.
  3. ^ Paul N. Edwards (1996). The Closed World: Computers and the Politics of Discourse in Cold War America. MIT Press. p. 107. ISBN 0-262-05051-X. SAGE—Air Force project 416L—became the pattern for at least twenty-five other major military command-control systems… These were the so-called "Big L" systems [and] included 425L, the NORAD system; 438L, the Air Force Intelligence Data Handling System; and 474L, the Ballistic Missile Early Warning System (BMEWS). … Project 465L, the SAC Control System (SACCS) [with] over a million lines, reached four times the size of the SAGE code and consumed 1,400 man-years of programming; SDC invented a major computer language, JOVIAL, specifically for this project. … In 1962 the SACCS was expanded to become [WWMCCS]
  4. ^ a b SAC missile chronology
  5. ^ a b Coleman, DA. "[biographical anecdote]". www.DAColema.com. Archived from the original on 7 April 2014. Retrieved 1 April 2014.
  6. ^ a b c Gorenstein, S. (15 March 1963). A Simplified Queuing Model for the 465L System (PDF) (Report). System Development Corporation. Archived from the original (Technical Memorandum) on 7 April 2014. Retrieved 2 April 2014. All incoming messages to the EDTCC are automatically switched and routed to the designated locations.
  7. ^ a b c "The IBM 4020 Military Computer" (PDF). IBM Federal Systems Division. 31 October 1959. Retrieved 28 September 2009.
  8. ^ http://bitsavers.org/pdf/ibm/4020/ Bitsavers.org IBM 4020 documentation
  9. ^ "PPT Slide".
  10. ^ a b Moriarty, J. K. (June 1975). The Evolution of U.S. Strategic Command and Control and Warning: Part Two (1954-1960) (Report). Institute for Defense Analyses. pp. 139–266.
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