(DOS) The original
disk operating system
from
IBM.
DOS was the low-end OS of choice on the
IBM 360, the
high-end system was called just "
OS". DOS had a smaller
kernel and less functionality than OS and could run on the
typical 32K 360/30 and 64K 360/40 class machines.
DOS was a successor to
TOS.
(DOS) The name of a number of operating systems which include facilities for storing files on disk,
often used to refer to
Microsoft DOS. Such a system must
handle physical disk I/O, the mapping of file names to disk
addresses and protection of files from unauthorised access (in
a
multi-user system).
A DOS should present a uniform interface to different storage
device such as floppy disks, hard disks and
magnetic tape drives. It may also provide some kind of locking to
prevent unintentional simultaneous access by two processes to
the same file (or
record).