Strange SCSI behaviour - maybe missing terminator?!?

[JohnFante]

And you can't mix SE and LVD on the same bus. Back when SCSI was popular you'd get servers with an UWSCSI raid controller for the harddrives and another SCSI2 controller for running the optical drives.
 
If you've still not got it sorted and you want to have them on the same bus then you will need to read up alot more on SCSI and do some trial an error adding and removing devices.

My HD's kan do both SE and LVD.

I will se if forcing SE gives any result. If not then I will switch to a IDE CD-ROM and give  my SCSI-problem a rest and read up on SCSI.

I am a bit tired off moving drives and jumpers around .... :-)

[JohnFante]

Well changing the jumpers to force single ended did'nt make any difference.

I have now installed a old IDE CD-ROM and it works flawlessly in OS4.1. Worked out of the box.

Somewhere along my fideling my OS3.9 install broke. And since my OS3.9 boot disk was created with my SCSI CD-ROM I get an error when I try to use it. Any suggestions on how to change a Emergency boot floppy from SCSI CD to IDE CD?

And last but not least thank you very much for all your help. :-D

I will get back back if I - eventually - find a solution to my SCSI-problem.

[Zac67]

And you can't mix SE and LVD on the same bus.

Yes, you can - it may or may not be smart though. A SCSI bus with a single SE device connected to it forces the bus to SE electrically: all return lines are grounded. Unless any of your LVD devices has a problem with SE in general (some - rare - are LVD only, not LVD/SE), everything is fine at UW speed (unless cable length for that mode is exceeded). Since the CSPPC is SE to start with, there's little to gain by forcing SE somewhere else.

On some PC HBAs there were even SCSI bridges to get an SE and an LVD domain in a single bus (e.g. AHA2940U2W).