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out of date.
Cannot Set Tabs Notification
An ASCII file that contains tabs is currently loaded in
memory, so you can't use the Display Command's Tab Stops
Option to change the value of a tab stop.
Unload the ASCII file, then change the Tab Stops option.