Only an 8.1 boot floppy can see everything.

[CelGen]

Running into a weird problem.

My Quadra 950 has a CD-RW, zip, MO and a SCSI disk attached to the external bus and two drives internally. I'm running 7.6.

Even if I boot in the base extensions mode I can only see the two internal drives and the CD drive. Lido by the way gets halfway through seeing the ZIP drive before completely going nuts and saying the drive needs a format, there is a cartridge in an empty drive, the bus is on fire, etc. If I boot say my 8.1 CD it does the same. Only two internal drives and CD.

If I however boot from my 8.1 boot floppy I can see everything, the MO will mount sans driver and I assume the zip would too if I could fit the driver on the floppy. All the other drives though won't mount because they are over 4gb. Snooper can see everything on the other hand.

There are no ID conflicts. The pram has been cleared. All devices show visual indications of being probed prior to boot.

 

[Charlieman]

See the link below for info about the strange Q950 SCSI bus:

http://support.apple.com/kb/TA27979?viewlocale=en_US

 

[CelGen]

I was aware that the 950 has a weird dual SCSI arrangement but I'm seeing devices on both the internal and external. Just not all of them will show up as useable under non-test conditions. The MO drive sits at the very end of the external bus so it means the cabling in between should be intact.

 

[uniserver]

i guess what i would do is disconnect them all... then connect them up one by one, and figure out what device might be causing the issue.

 

[CelGen]

SCSI Voodoo it was.

The bus had been going:

[internal drive 1 - internal drive 2]{CD-RW 4 - Zip 6 - external drive 3 - MO 5}

...with [] being the internal bus and {} being the external bus. The entire bus worked when reorganized to:

[internal drive 1 - internal drive 2]{Zip 6 - external drive 3 - MO 5 - CD-RW 3}

The only change was a HD50 cable with an HD50-Centronics 50 cable that was longer. Bizarre. :-/