4 Jul
2016
4 Jul
'16
4:07 a.m.
On Fri, Jul 01, 2016 at 08:47:01AM -0400, William Cheswick wrote:
Actually, MS-DOS was a runtime system, not an operating system, despite the last two
letters of its name.
This is a term of art lost to antiquity.
Run time systems offered a minimum of features: a loader, a file system, a crappy,
built-in shell,
I/O for keyboards, tape, screens, crude memory management, etc. No multiuser, no network
stacks, no separate processes (mostly). DEC had several (RT11, RSTS, RSX) and the line is
perhaps a little fuzzy: they were getting operating-ish.
I seem to recall a whole bunch of DOS's for different systems in the early
80's,
where the term seemed to be used in the sense of a System for Operating a Disk.
DF