Yo!
I think I've deciphered my problem. My GVP controller is too old, it's
actually ROM version 1.0, an "Impact" model card. Although it has some kind
of RDB, it's not an official one, which confused me. Another problem was
that I didn't have the A2091 file in my Expansion drawer. Although the
person who gave me the card assured me it wasn't necessary, because they
dropped it in other machines all the time and it worked fine; it turns out
they had the A2091 file in their expansion on the primary drive anyways. I
bought a HardFrame a few weeks ago trying to get my CD-ROM drive attached,
and it wouldn't work with the GVP in place. I was able to get it working
with the A2091 in at the same time. So, the long and the short of it is, I
ordered a new GVP '030 Combo board today, which has a built-in SCSI that
should work with both a dropped-in A2091 card and/or my CD-ROM drive.
I think I'll have a hardware sell-a-thon soon… maybe my present 28 Mhz,
4 meg GVP '030 will go, along with a Micron/ASDG 2 meg board, and the older
GVP SCSI adapter. I'll take $10,000 for the lot of them, or best offer. 🙂