(BOS) An early [when?] IBM
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.
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