There are new ROM chips available for the A2620 and I believe they are
supposed to smooth out some rough edges. I think they help the 2620 exist
with an AT BBoard in your machine. Also Dave Minnich has said they should
smooth out some of the odd things I've noticed with my machine. Things
like it not really going to the GURU, mine will just hang up on me! I
think the new chips help that. The new ROMs have the following part
numbers: 390282-04 and 390283-04 My dealer was finally able to order them
for me, he had a problem with Commodore but has that resolved now. I'm not
sure of the prices on them as a friend of mine OWNS the dealership and I'll
not be paying list prices on them. Hope that helps you a little bit. If
you need more info let me know as I should have the chips in about a week
and I could report to you what gets fixed if you'd like!