I may have found an undocumented Commodore command for PET.
"SCRATCH *,8" and "SCRATCH *,9", if I recall correctly from when the command broke my computer, doesn't error out on a PET 4016 Model-N with pet basic 4.0 and a 2031 single sided 5.25" floppy diskette drive, but does seem to glitch a possible PLA (programmable logic array) in the drive.
The two commands seem to have no effect other than lock out directory listing, and it stays locked out permanently until a file is successfully loaded off the same diskette that was in place when it was locked. Apparently, a person can't even load off a different diskette.
Power cycling the drive and computer and even waiting for the capacitors to all bleed off doesn't seem to fix it either.
"SCRATCH *,8" and "SCRATCH *,9", if I recall correctly from when the command broke my computer, doesn't error out on a PET 4016 Model-N with pet basic 4.0 and a 2031 single sided 5.25" floppy diskette drive, but does seem to glitch a possible PLA (programmable logic array) in the drive.
The two commands seem to have no effect other than lock out directory listing, and it stays locked out permanently until a file is successfully loaded off the same diskette that was in place when it was locked. Apparently, a person can't even load off a different diskette.
Power cycling the drive and computer and even waiting for the capacitors to all bleed off doesn't seem to fix it either.