Editing BOS/360 (section)

== Origin ==
BOS was one of four System/360 Operating System versions developed by the IBM General Products Division (GPD) in [[Endicott, New York]] to fill a gap at the low end of the System/360 line when it became apparent that OS/360 was not able to run on the smallest systems. [[IBM Basic Programming Support|BPS (Basic Programming support)]] was designed to run on systems with a minimum of 8&nbsp;KB of main storage and no disk.  BOS was intended for disk systems with at least 8&nbsp;KB and one [[IBM 2311|2311]] disk drive.<ref>{{cite book |last1=IBM Corporation |title=IBM System/360 Basic Operating System Programmer's Guide |date=Sep 1967 |url=http://bitsavers.org/pdf/ibm/360/bos_bps/C24-3372-6_BOSpgmr_Sep67.pdf |access-date=Jan 24, 2022}}</ref> [[DOS/360 and successors|DOS and TOS]] were developed from BOS for systems with at least 16&nbsp;KB and either disks (DOS) or [[Magnetic tape|tape drives]] only (TOS).

BOS was released in October 1965, nearly two years before OS/360,<ref>Pugh, Emerson, et al. "IBM's 360 and Early 370 Systems". MIT Press, 1991, p. 331</ref> thus BOS was the only disk based operating system available at launch for a machine that was marketed as disk based.