Special IBM MCA system (Mopar) Help

This is slightly off-topic (as the system itself is from ~1991), but most of the hardware I'm dealing with dates to 1989 or so... I'm working with an IBM-built MCA-architecture machine called the MDS - Mopar Diagnostics System. You'll probably find one at your local Daimler-Chrysler fixemupper dealership. Anyway, the box at a local dealership here decided to take a crap - specifically, one of the SCSI 1x CD-ROMs seems to have died. I've tried replacing it with a standard 4x SCSI - trying every jumper permuation I could think of, to no avail. Either it wankers the SCSI bus, or just isn't recognized by the system. The system seems to run (at least) a chunk of DOS, then boots from *both* of the CD-ROM drives to have all the functions available. Anyone here deal with non-IBM scsi drives in an IBM MCA box? (BTW, the System # is 7785-110, the IBM part # for the SCSI card is 66g1080. I've tried searching the web for darned near anything (including a few PS/2 FAQs) to no avail.) Thanks for any and all help you may be able to provide, Roger "Merch" Merchberger -- Roger "Merch" Merchberger --- sysadmin, Iceberg Computers Recycling is good, right??? Ok, so I'll recycle an old .sig. If at first you don't succeed, nuclear warhead disarmament should *not* be your first career choice.