Re: Apple Rev.C SCSI Jumpers

[dempson@actrix.gen.nz (David Empson)]

Stingray <stingray@webzone.net> wrote:

> OK, I set my Rom 3 back up the way it was with the HS scsi card. I then
> exchanged the Rev C scsi card for the HS (in slot 7), changing no settings on
> the GS, and putting the jumper block on the far right set of pins (as
> recomended by Wayne). I got the following:
> 
> 0010170: 00 00                   BRK00
>  A=FF00 X==00C9 Y=0010 S=0171 D=0000 P=B0 K=00 M=0C Q=A8 L=1 m=1 x=1 e=1
> 
> I'm pretty sure I got all that down accurately.

Nope.  There is at least one digit too many in the address on the first
line (it should be six digits, not seven).  There is also only one
equals symbol after the "X" in the second line, and a space between the
"BRK" and "00" on the first line.  The rest might be correct.

> Does this mean anything to anyone?

The processor was trying to execute code at a location which I can't
quite determine (due to the formatting error in the address), and ran
into a "break" instruction, which usually causes the system to drop into
the monitor and display this message.

Guessing that the address might have been "001017", then it is trying to
run code in RAM, somewhere between the normal place where an Applesoft
BASIC program starts and the hi-res screen.  This is not a normal place
for code to be executing if you are booting a card.

(If it was actually "010170" then that is even less likely - running
code inside the stack space in auxiliary memory.)

I suspect your SCSI card's EPROM may be corrupted, or there could be a
hardware fault on the card.

One question: is it actually the revision C firmware?  The EPROM should
be labelled "341-0437-A".  If it says "341-0112A" or "341-0112B" then
you have the revision A or B firmware and should upgrade it.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand