Hi Derek,
Is that an unmodified DIO board?
If so, can you confirm if LEDs show differently when you're just running CP/M and swap between different drives on the CF card? Also, if you hold down any of the buttons and do a DIR in a drive that you know has files in it, do the files show up?
The reason I ask is that I was doing some testing yesterday, in particular trying out the
diode fix that gfcwfzkm posted a couple of days ago. I found that I could use CP/M fine, and use the unmodified DIO module fine within mBASIC. However, within CP/M itself, I would have different LEDs lit depending what drive I was in, or if I copied everything from drive C to drive B then disco mode was activated. Holding down a button when doing a DIR normally resulted in a empty directory reply (although release the button, DIR and all the files are back).
The diode fix did indeed cure that, and after swearing a lot at ED, ASM and LOAD, I was able to write short code that could read the buttons and control the LEDs from CP/M itself.
Cheers
Spencer