Subject: Re: SCSI info with i386 port
To: Brian Moore <ziff@eecs.umich.edu>
From: Ken Hornstein <kenh@entropic.com>
List: current-users
Date: 09/28/1994 11:12:00
>I have a question that I was wondering if anybody could give me some info
>about. Does NetBSD-1.0 Beta support Wide SCSI-2, or SCSI-3? I have seen a fe
>w
>machines come out recently that say they support Wide SCSI-2, and one that
>claimed support for SCSI-3. While I doubt the claim of SCSI-3 compliance (
>Last I heard, the SCSI-3 committee was still a long way away from agreeing on
>the standard, but I could be totally wrong about that ), I would be interested
>in getting a Wide SCSI-2 board if they were supported. Does anybody know of
>any SCSI board, of course with the exception of the 'evil, wicked and nasty'
>Adaptec boards, that support Wide SCSI-2?
I am pretty sure that "wide" SCSI-2 requires a differential interface or a
special cable (78 pins). The end result is that you have to buy special "wide
SCSI" peripherials that aren't compatible with other host adapters (I _think_
you can run both normal SCSI and wide SCSI peripherials on the same bus
with some funky cabling, but I'm not sure).
I know Buslogic makes a differential controller, and it should "just work"
with the bt742 driver, but I don't think anyone's tested it. I don't know
if the higher-level SCSI code would have to be modified to support Wide
SCSI or not.
Unless you have some really huge I/O requirements, I would advise against it;
there are many unknowns here and you'd have to spend a lot of money and time
to get it all working. Most of the mid-to-high range cards support FAST
SCSI, which is pretty cool and is supported by most newer drives.
--Ken