Commodore 1581 - Appendix B: DOS Error Messages

APPENDIX B
DOS ERROR MESSAGES
Many commercial program diskettes are intentionally created with
one or more of the following errors, to keep programs from being
improperly duplicated. If a disk error occurs while you are making a
security copy of a commercial program diskette, check the program's
manual. If its copyright statement does not permit purchasers to copy
the program for their own use, you may not be able to duplicate the
diskette. In some such cases, a safety spare copy of the program
diskette is available from your dealer or directly from the company for
a reasonable fee.
00: OK (not an error)
This is the message that usually appears when the error channel
is checked. It means there is no current error in the disk unit.
01: FILES SCRATCHED (not an error)
This is the message that appears when the error channel is
checked after using the SCRATCH command. The track number
tells how many files were erased.
02: PARTITION SELECTED (not an error)
The disk partition requested has been selected.
-NOTE
If any other error message numbers less than 20 ever
appear, they may be ignored. All true errors have numbers
of 20 or more.
20: READ ERROR (block header not found)
The disk controller is unable to locate the header of the request
ed data block. Caused by an illegal block or a header that has
been destroyed. Usually unrecoverable.
21: READ ERROR (drive not ready)
The disk controller is unable to detect a sync mark on the desired
track. Caused by misalignment, or a diskette that is absent, unfor
matted or improperly seated. Can also indicate hardware failure.
Unless caused by one of the above simple causes, this error is
usually unrecoverable.
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