On Thu, 16 Feb 2012 16:55:52 +0000, David WE Roberts wrote:
The cables and
terminator came with the scanner - previously used with Apple hardware,
I believe.

Check what SCSI device ID the scanner is set to; in the SCSI world it was
typical to have the *controller* set to ID 7, but I have a feeling Apple
were different and sometimes (often / always, even?) set their controller
to ID 6 - which means there's a chance your scanner's set to 7 and is
conflicting with the PC's controller.

I am arranging to get hold of the bits so I can have an extended play.

Good

The connectors between card and scanner are D type (68 pin rings a bell)
and the terminator is markes Passive (which may not be a good sign) and
in IIRC Centronics style.

If they're 68 pin then it's a wide bus; you need to make sure[1] that the
high side of the bus is terminated as the scanner's likely a 50 pin
narrow device and will only be able (either by itself or by a terminator
connected to its narrow pass-through port) to terminate the low side of
the bus.

[1] the cable you have might do it, or that might be why you have that
weird terminator with the two connectors, or on many Adaptec cards it's a
BIOS option to terminate just the high side of the external wide bus.

Heck, there's even a wikipedia entry for it:
http://en.wikipedia.org/wiki/SCSI_high_byte_termination

Just Googling now suggests that I may need an active terminator.

I think you'll probably be OK with passive terminators - the scanner's
not particularly high-speed (compared to say, a hard disk), and it's the
only thing on the bus (other than the Adaptec itself), and you'll be
connecting it all with a shielded cable (things can be a bit more picky
when it comes to ribbon cable internal to a machine).

Even with the cabling and termination less than perfect, I think there's
a fair chance it should still respond to device identify at startup (even
if it subsequently proved flakey during use), so I think you've got some
more fundamental problem at play (hardware fault, cable fault,
configuration setting etc.)

cheers

Jules