Autobooting 3/180 from sd0 rather than xy0

[Ittai Hershman]

We have a Sun-3/180 with an old 130meg Fujitsu drive on an XY controller.
It came with a SCSI cartridge tape drive, and as a result I was able to
hang a Wren-IV off th external SCSI port.

The problem is that as long as I have physical access to the console I can
boot off the Wren with: B SD(), but I cannot do remote reboots (or a
"shutdown -r") because the system's PROM seems to default to the XY
controller.

Does anyone know how to modify the boot default disk?

Thanks,
-Ittai

PS: Please respond to me, I will summmarize to sun-spots/comp.sys.sun.