ZFDC Format, Read, and Write question with 1.44 mb 3.5" diskettes

I have a problem I am hoping someone can point me in the right direction…

On my ZFDC board I have it configured for 2 1.44mb 3.5” Teac drives. (System boots from IDE CF)

I have configured and compiled my bios (HFL3.ASM) to initialize drive C and D as “CPM144”.

Here is what happens…
1. I boot the system and start ZFDCDIAG and set the format of Drive C to ’16’ and then FORMAT the diskette.
2. ESC to CPM
3. I can type C: at the prompt and log to drive C
4. I can copy files to and from the new disk
5. I can run programs from the new diskette
6. I can RESET the computer and still do everything in steps 3 – 5

If I POWER OFF the system, however, and then turn it back on and start at step 3 above I get an I/O error and I am never able to read the disk.

In other words everything continues to work well with the newly formatted disk until I power off the system, and then I must start over with a FORMAT etc.

What am I missing here? Is my BIOS not recognizing the format I am writing during a FORMAT and this causes a problem at power up, but not a reset?

Also – if I use a standard pre-written DOS disk I can power up the system and log to drive C – it is only the disk I have written that are the problem, and only after power-down. This tells me my Bios is working in the INIT and READ sections at least..

Both drives have the same behavior so I don't think it is a drive hardware issue.

I appreciate any and all suggestions -

Thomas