After alot of investigation I successfully patched FORMAT/CMD command to remove "motor too slow" error, and now formatting works.
Timing speed is software based by comparing a few values, so simply removing the conditional jump made the job.
This is the code I found:
Code: Select all
5546 2113f4 ld hl,0f413h
5549 19 add hl,de
554a 21685a ld hl,5a68h --> motor too fast
554d d2b256 jp nc,56b2h
5550 2197f3 ld hl,0f397h
5553 19 add hl,de
5554 218e5a ld hl,5a8eh --> motor too slow
5557 dab256 jp c,56b2h --> CHANGE THIS TO NOP-NOP-NOP TO PATCH <--
555a c9 ret
This fix is related to NEZ80 with NE-DOS version G.1.0. I don't know if it's similar to NEWDOS 2.1, but maybe. I'll need to check it.
Now I need to fix the COPY command that has the same problem when copying an entire floppy: infact it makes a formatting at the start, and it returns the same error.
Thank you.
Roberto