Computing Dictionary
Basic Operating System definition
operating system (BOS) An early [when?]
IBM operating system.
According to folklore, BOS was the predecessor to
TOS on the
IBM 360 and it was
IPL'd from a
card reader. It may have been intended for very small 360's with no disks and limited tape drives.
BOS died out really early [when?] as disks such as the 2311 and 2314 became common with the
IBM 360, whereas disks had been a real luxury on the
IBM 7090.
(1999-01-29)