On Wed, 6 Mar 1996, Allen Briggs wrote:

> > Is MacBSD's SCSI driver a ground-up construct or a partial takeover?
> 
> It is a ground-up construct.  Actually, there have been a couple...
> There are two available in the tree right now--each with problems.
> Unfortunately, I lack a ZIP or Syquest to reproduce the problems on
> and no one who has been able to reproduce the problems has made any
> attempt (that I know of) to track down the source of the problems.

I'm not sure about the Syquest 135, but my SQ270 still has some problems 
with linked SCSI commands.  I've got my kernel compiled with linked 
commands totally disabled to get around that.  Here's the patch:

  --- /usr/src/sys/arch/mac68k/dev/ncr5380.c	Mon Feb 19 04:28:18 1996
  +++ src/sys/arch/mac68k/dev/ncr5380.c	Mon Feb 19 12:03:15 1996
  @@ -50,7 +50,7 @@
    * that we've already checked out
    */
   u_char	ncr_will_link = 0x00;
  -u_char	ncr_test_link = 0x00;
  +u_char	ncr_test_link = 0x7f;
   
   #endif	/* AUTO_SENSE */
 
Of course, you'll need to be able to compile your own kernel to take 
advantage of this patch.  I think Allen was going to offer a way to patch 
an already-built kernel, but I haven't seen it yet.