NeXT SCSI problems
The old 400MB drive on my cube (68030) has finally died so I got hold of an HP SureStore C2490A which is a 2.1GB drive. I have found the details of the drive on the HP site (http://www.hp.com/cposupport/D_index8/hpsurestor9696_6.html) - as far as I can tell the jumper settings on the drive that I've got are the third ones listed.
I have tried various combinations of termination and SCSI ID but to no avail, the cube always gives a 'SCSI Bus error' during boot, I was reading yesterday that the drive needs to using Asynchronous transfer mode but I cannot see how to set this on this drive.
All black machines are strictly SCSI-I. Deviations from this standard render drives unbootable and lead to I/O trouble on heavily loaded systems.
Most prominent disruptive SCSI-II features are "synch negotioation" and "unit attention". To sum it up, the boot code in the ROM-monitor is not prepared to see any SCSI traffic that is not a response to an explicit request, any initiative taken from a bus device has a stunning effect.
this problem looks like the same on my machine (after the installation of a Seagate 2.1 GB HD in my NeXTstation Mono).
Check the termination of the SCSI Bus. After connecting an external SCSI-Terminator on the external! SCSI Port my machine boots correctly.