Remote Access Computing (RAX)
OS familyRACS
Working stateDiscontinued
Initial release1966; 58 years ago (1966)
Marketing targetIBM mainframe computers
Available inEnglish
PlatformsIBM System/360
Preceded byRACS
Succeeded byMUSIC

IBM Remote Access Computing (RAX) is a discontinued early time-sharing system for IBM System/360 introduced in 1966.[1] RAX was based on an earlier system, RACS. developed jointly by IBM and Lockheed Aircraft in Marietta, Georgia in 1965. The system influenced a number of other timesharing systems including MCGILL-RAX from McGill University,[2] McGill's MUSIC,[3] and Reactive Terminal Service (RTS) from ITT Data Services.[2][4] In the 1970s Boston University used RAX as the basis of its VPS system, which ran as a guest operating system running on VM/370.[3]


RAX was available from IBM as program number 360A-CX-17X, and runs on System/360 Model 30 and above.[1]As announced, it runs on systems with as little as 64 KB of main storage, and supports a mix of up to 63 IBM 1050 typewriter terminals and IBM 2260 display terminals. The languages supported are BASIC, FORTRAN IV, and IBM Basic assembly language.[note 1] In a minimal system with 64 KB memory, user programs can be up to 32 KB, with larger programs allowed on larger systems.[5]


In 1968 RAX was used by the United States Department of Agriculture for their Washington Data Processing Center.[6] It was used in a number of colleges, universities, and corporations, including McGill, Boston University, St. Andrew's in Scotland,[7] The University of Rhode Island, and Bell Aerosystems.[2]


  1. ^ RTS also supported COBOL.


  1. ^ a b IBM Corporation (23 January 2003). "DPD chronology". IBM Archives. Retrieved Apr 29, 2021.
  2. ^ a b c Miller, Roy Watt. "MULTIPLE REGIONS FOR THE MCGILL-RAX TlME-SHARING SYSTEM". Library and Archives Canada. Retrieved Apr 29, 2021.
  3. ^ a b "Boston University's RAX Library". 12 January 2012. Retrieved Apr 29, 2021.
  4. ^ "(advertisement)". The Pittsburgh Press. June 15, 1969. Retrieved May 2, 2021.
  5. ^ IBM Corporation (August 1967). Catalog of Programs for IBM System/360 August 1967 (PDF). p. 5. Retrieved Apr 25, 2023.
  6. ^ Department of Agriculture Appropriations for 1971. 1970. p. 17. Retrieved Apr 29, 2021.
  7. ^ "Thirty years ago . . ". University of St. Andrews. Retrieved Apr 29, 2021.