Reply 16780 of 17314, by kdr
Horun wrote on 2020-09-27, 03:31:
Wow, is that motherboard white ? Can you post a good picture of the motherboard ?
Also: if you did not format that MFM drive with that controller you could have odd issues if formatted with a different but same make/model controller... just a thought.
MFM drive had a fresh low-level format, and as mentioned the issue seems to also affect the floppy. I can reproduce it with two different floppy controllers as well. I'm going to write a small test utility to exercise the floppy (far easier to debug because the controller is so simple) and see if I can find a particular bit pattern in the error bytes.
And yes - it is a pure white soldermask on this motherboard! It looks kind of like a NuXT except manufactured in the '80s. Here's a better photo of the entire board.