🚀 go-pugleaf

Hello,

I'm having a strange problem that I hope someone can help me with.  I have an
A1000 on which I have been running a 1 Meg Starboard2 for about a year.  About
three months ago I added a C Ltd SCSI 1000 host/controller board with an ST-412
and Q504 disks connected through an Adaptec 4000 controller.

For about three months, this system ran perfectly without any problems. 
Recently, I began to get the following GURU:

            00000004.00200ED2

The system boots up perfectly, runs for awhile, then crashes with the above
number.  I have found that I can *always* get the machine to crash if I run
AZComm or VT100 and log in somewhere.  The machine will always crash (again,
with the same number) after about a screenful's worth of data.

I experimented with different versions of Kickstart/Workbench (1.2, 1.3), not
loading the SCSI driver software, loading programs from floppy, etc.  All gave
the same results.  Finally, I discovered that if I leave *only* the Starboard2
or *only* the SCSI host/controller attached to the Amiga, the system will run
fine!  It is only when I have both simultaneously connected that the machine
consistently crashes.

So I have the following questions:

	- it seems obvious that my problem has to do with the expansion bus,
	  but it isn't obvious to me if it is caused by overloading the data/
	  address lines or the power supply; how do I tell?

	- what is it about using the serial port (via VT100 or AZComm) that
	  causes my crash to occur so "reliably"?

	- why did the system run perfectly for months, then begin to fail 
	  consistently

Many thanks for any help anyone can offer!