[net.micro.apple] a bizarre bug

jbyrd@BBN-VAX.ARPA (06/14/84)

From:  James Byrd <jbyrd@BBN-VAX.ARPA>

I've run into a weird problem, and I'm not sure where to begin on solving
it.  I have a IIe revision B, and a Microsoft Premium Softcard IIe
(80-column 64K CP/M), Super Serial Card, and Duodisk controller.

I have a copy of Apple Access (a ProDos-based disk), and I've run into a
strange problem I've never seen before.  When the disk is booted, it
normally shows one text screen (all in 80 columns), then a second one, and
finally gets into the program.  What often happens instead is that I get the
first screen normally, but then I get garbage overlaid on top of the second
screen.  One fourth of the character position have garbage characters, in a
regular array (every other position on every other row).  Not only that, I
get a sequence of a musical note(??!) repeated a few times.

If I just try rebooting or power-cycling, I tend to get the problem again.
One thing that often works is to run self-test (control-closed-apple-reset),
and then boot.

I've never had any problem with my Microsoft card on any other disk, but I'm
tending to suspect the card.  Can anybody give my any ideas as to what to do
to solve this one?  I'm stumped.

Jim Byrd