50 & 68 pin SCSI-2

From: Bob Lafleur <bob_lafleur_at_technologist.com>
Date: Sun Jun 9 09:11:16 2002

Dick,

Thanks for the info. I'll look into these adapters your talking about.

The specific wide drives I have that I'd like to connect to the narrow
bus are RZ29's. So I'll have to see what I can find out about
configuring them for narrow bus.

   - Bob

-----Original Message-----
From: cctalk-admin_at_classiccmp.org [mailto:cctalk-admin_at_classiccmp.org]
On Behalf Of Richard Erlacher
Sent: Sunday, June 09, 2002 10:06 AM
To: cctalk_at_classiccmp.org
Subject: Re: 50 & 68 pin SCSI-2


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 - 09:11:16 BST