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out of date.
SYS1811
SYS1811Explanation
The program attempted to perform an instruction that the system cannot
perform. The software diagnostic code allows determination of what type of
instruction was attempted.
Action