The pages on this site contain documentation for very old MS-DOS software,
purely for historical purposes.
If you're looking for up-to-date documentation, particularly for programming,
you should not rely on the information found here, as it will be woefully
out of date.
SYS1231
SYS1231Explanation
An incorrect drive specification was entered or a fixed disk was
specified. A fixed disk is not an acceptable drive for this program.
Action
Retry the command using a correct drive specification.