MS-DOS 1.25

MS-DOS 1.25 was released in 1982-08 as the first general release to OEM customers other than IBM, so it was used by all the first clone manufacturers. Some OEMs labeled their release with different version numbers (e.g. COMPAQ), but they are all based on version 1.25.

It supported both single sided (160KB) and double sided (320KB) 5.25" floppies and there was no sub-directory support (all files must be located in the root directory). As a result of that,,   and other symbols can be used in file names.

Versioning
in this release should always report version 1.25 and  will report version 1.17, 1.18 or custom versions depending on the revision. The original non-OEM MS-DOS 1.25's  reports version 1.17 according to the source code released by Microsoft.

Some OEM releases has an extra  or   at the end of the version string. means the source was assembled with the  switch and   means the   switch was used.

Changes from MS-DOS 1.24
MS-DOS 1.24 corresponds to IBM PC-DOS 1.10 and there is only one minor change between the two versions as described by the writer of DOS, Tim Paterson. The change was a marker being placed at end of the directory to speed up searches.

Internal commands
The Command Interpreter,, supported these commands: