from
The Free On-line Dictionary of Computing (8 July 2008)
DOS/360
<operating system> The {operating system} announced by {IBM}
at the low end for the {System/360} in 1964 and delivered in
1965 or 1966.
Following the failure of {OS}, IBM designed DOS for the low
end machines, able to run in 16KB(?) and 64KB memory.
DOS/360 used three {memory partitions}, but it had no serious
{memory protection}. The three partitions were not
specialised, but frequently one was used for {spooling}
{punched cards} to {disk}, another one for {batch job}
execution and another for spooling disk to printers.
With DOS/VS, introduced in 1970, the number of partitions was
increased, {virtual memory} was introduced and the minimum
memory requirements increased.
Later they released DOS/VSE and ESA/VSE. DOS/360 successors
are still alive today (1997) though not as popular as in the
late 1960s.
Contrary to the Hacker's {Jargon File}, {GECOS} was not copied
from DOS/360.
(1997-09-22)