Just to add more to this discussion.
I used to repair Amigas and also worked for a Canadian Amiga Hardware Manufacturer and wrote SCSI device drivers for their line of Comspec SCSI Controllers.
I have probably configured at least 10 Dirrerent Manufacturers Amiga SCSI Controllers and have found that unlike the PC World no standards were conformed to when it came to SCSI on the Amiga.
Controller Termination is handled differently on almost every SCSI controller I have seen.
The CBM A2091 had the Terminators Soldered onto the controller card, these Terminators should be removed if using both internal and external devices.
The Comspec Controllers used removable SIPP Resistor packs as termintors. Installed if using internal drive only.
Its been years since I have seen the Supra Controllers so don't remember their configuration.
Cheers
Shaf
