SCSI can be a major pain. I have a Blizzard SCSI-IV and it has given
me quite a bit of grief.
I suspect most of the trouble I've had is due to it being manufactured
by DCE and there being a bit of tarnish on the contacts - however I'm
sure my cabling is just as much a problem.
The problem is that SCSI-2 is so fast the data becomes a radio wave
and noise can bounce down the cable, reflecting back off all adaptors
in the chain. The terminators sort of filter or regulate things but
TermPower is another spanner in the works.
The big trouble is going from a 50-pin ribbon to a scanner and back
(since a scanner will either require a terminator block or a pass-thru
cable for more devices.
I've managed to get hold of a Honda 50-pin internal SCSI ribbon with
an active terminator on the end, which is handy, as I have no idea if
my CD-ROM drive is supplying active or passive termination and
TermPower (and the SCSI-IV must be using active as it's
SCSI-2).
Also, whilst I have kept my chain relatively short (under 2m) I get
horrible data unreliability with Synchronous mode (7MB/s).
AmigaOS 4 has a special HDToolBox section dedicated to SCSI bus tests,
the rest of us just have to get pot lucky!
:-)
