Subject: Re: kern/2841: NCR 53c810 driver is slow. Here's a faster one
To: None <netbsd-bugs@NetBSD.ORG>
From: Jim Howard <jiho@mail.c-zone.net>
List: netbsd-bugs
Date: 10/18/1996 11:05:38
At 07:23 PM 10/16/96 -0500, Dave Huang <khym@bga.com> wrote:

> I don't have wide either, but I did see a lot of places where (something &
> 7) was changed to (something & 0xf).

Those places increase the number of targets (devices) supported from 7 to
15.  That would be useful for some people, it has *no* bearing on your
performance case.

I've deduced that the 53C860 is a narrow Ultra SCSI chip.  So here's the lineup:

   53C810    8-bit Fast SCSI-2           full support in NetBSD 1.2
   53C825   16-bit (wide) Fast SCSI-2    full support in NetBSD 1.2
   53C860    8-bit Ultra SCSI            new in your patch
   53C875   16-bit (wide) Ultra SCSI     partial support in 1.2, full in patch?

Your patch seems to fill out the device support.  But I'm *still* at a loss
as to why you would need it to get your Fast SCSI-2 Quantum Atlas running at
normal speed with a 53C810.


--Jim Howard
  jiho@mail.c-zone.net