BESYS

BESYS (Bell Operating System)
DeveloperBell Labs
Written inIBM's FORTRAN and North American's Symbolic Assembly Program (SAP)
Working stateDiscontinued
Initial release1957; 67 years ago (1957)
Latest releaseBE90 / 1968; 56 years ago (1968)
PlatformsIBM 704

BESYS (Bell Operating System) was an early computing environment originally implemented as a batch processing operating system in 1957 at Bell Labs for the IBM 704 computer.