50 & 68 pin SCSI-2

From: Richard Erlacher <edick_at_idcomm.com>
Date: Sun Jun 9 09:05:56 2002

You're right, of course, but it's also possible to configure your wide SCSI
devices to work on a narrow controller. I have that configuration working
with SCA devices, which make it somewhat easier (at least less costly) but
it's necessary that you consult the documentation for your wide drives to see
about configuration details. The drives (several types) that I have all allow
for "narrow" configuration with a single jumper. That's necessary, but not
sufficient, since you also need the adapter cable, or an adapter board. If
you configure the drive for narrow transfers, I doubt it matters whether you
terminate the upper part of the bus appropriately, but if you have the option,
I'd terminate the upper bus anyway.

If you don't have an adapter and can't find one that's cheap enough, you could
use one of the 3-way adapters that abound on the web for attaching SCA drives
to a WIDE controller or a Narrow controller. There are at least three types,
and what you want is the one that has BOTH the wide and narrow connectors.
You're not required to use the SCA connector, though that's how the boards are
intended to be used, and can then connect both a WIDE cable and a NARROW cable
to the board, presumably with the NARROW cable going to your controller. I've
done this with complete success, so you should have no trouble.

Dick

----- Original Message -----
From: "Bob Lafleur" <bob_lafleur_at_technologist.com>
To: <cctalk_at_classiccmp.org>
Sent: Saturday, June 08, 2002 10:18 PM
Subject: 50 & 68 pin SCSI-2


> I've got 50-pin SCSI-2 connectors inside my MicroVAX 3100. Is there a
> way to use 68-pin devices? The RZ26L and RZ28's in it are 50-pin, but I
> have some RZ29's that are 68-pin and I'm wondering if there is in
> adapter? I suspect not, but just asking.
>
> If I'm not mistaken, it is possible to "go the other way" and use 50-pin
> devices on a 68-pin cable with an adapter that terminates that "extra"
> lines, correct?
>
> - Bob
>
>
Received on Sun Jun 09 2002 - 09:05:56 BST