I have 3 SCSI buses on my computer.  They are driven by PCI controllers.
Counting from the slot closest to my CPU, they are:
1) external narrow single-ended bus; Bustek BT-946C
2) internal narrow single-ended bus; ASUS PCI-SC200 (based on NCR chipset)
3) external wide differential bus; Bustek BT-958D

Note that the Asus motherboard has a SCSI BIOS on it, and the PCI-SC200
apparently uses that chip (it was an inexpensive add-on card).

Unfortunately, the BIOS seems to boot from the drives on the PCI-SC200.
I'd like it to boot from the higher-performance BT-958D.

The order of the boot-time messages is as follows:
1) PCI-SC200
2) BT-958D

Note that there is no boot-time output from the BT-946C controller.

NetBSD's autoprobe finds them in this order:
1) BT-958D
2) PCI-SC200
3) BT-946C

Does anyone know what controls these orderings?
I'd like to be able to control them; mostly so that I could boot with
the root on a higher-performance drive, but also because having different
orderings is confusing.

Thanks
VaX#n8