Right. My AppleCD 300i Plus appears to be shot. Also, I found that the drive config was set incorrectly on this system in the first place. Both CD-ROM and HDD was set to SCSI ID0 and they were on the same cable (the secondary, which can only do 5MB/s).
I've now put my Plextor Plexwriter PX-R820Ti on the secondary cable, and activated internal termination.
I've also attached the HDD to the primary (FastSCSI) port, and put a terminator on the end of the cable. This gives me a booting OS9 system with working CD-ROM drive.
I tried swapping out the HDD for my brand new BlueSCSI v2, with two 2GB HDD imaged (correctly named HD00_512, HD10_512 etc.) and since there's a terminator on the end of the cable, I set the jumper to "Term Off". I boot the system with my Power Macintosh 6100/7100/8100 System Software CD in the CD-ROM drive, and... No HDD. Setting the jumper to "Term On" however, makes the Mac see the drive images on the BlueSCSI.
But, surely this would cause double termination, and potential issues? It didn't seem to want to work with "Term On" and no terminator on the cable when I tested earlier, so this seems a bit strange to me.
Any BlueSCSI wizards here who can explain this?