IBM AP-101 general-purpose computer

https://gandalfddi.z19.web.core.windows.net/Shuttle/IBM%20AP-101S%20General%20Purpose%20Computer%20With%20Shuttle%20Instruction%20Set.pdf

Article

  • Technical document covering the IBM AP-101S, the Space Shuttle’s flight computer
  • Part of IBM’s System/4 Pi avionics computer family
  • Includes the Shuttle-specific instruction set architecture

Discussion

  • Ken Shirriff’s recent writeup on the System/4 Pi family linked as companion reading
  • Commenters noted HAL/S (Shuttle programming language) docs and compared to Artemis/Orion using MISRA-C

Discuss on HN


Type Link
Added Apr 17, 2026
Modified Apr 17, 2026