[272] in linux-scsi channel archive
Buslogic SCSI and floppy problems
daemon@ATHENA.MIT.EDU (Leonard N. Zubkoff)
Wed Jun 21 03:48:30 1995
Date: Tue, 20 Jun 1995 23:51:14 -0700
From: "Leonard N. Zubkoff" <lnz@dandelion.com>
To: sbw%tapestry.UUCP@cs.arizona.edu
Cc: linux-scsi@vger.rutgers.edu
In-Reply-To: Steve Wampler's message of Mon, 19 Jun 1995 19:51:52 -0700 <m0sNtPs-000GtUC@tapestry>
From: sbw%tapestry.UUCP@cs.arizona.edu (Steve Wampler)
Date: Mon, 19 Jun 1995 19:51:52 -0700
Hmmm, I have a similar problem but figured it was something I'd done.
I have Buslogic 445C VLB controller, an IDE VLB controller, and an
ATI VLB GUP graphics cards (3 VLB slots), running under Linux 1.2.10.
I haven't tried much with the floppy, but ftape (2.03b) isn't working
correctly - tapes are sometimes not recognized, and when trying to
do a backup, ftape begins to lose track of where it is on the tape
after a few minutes and starts performing long seeks across the tape.
This is with the floppy and floppy tape attached to the IDE card. I
figured I would try it attached to the Buslogic card next.
In thinking about this problem further, I really doubt the controller would
function at all in a non-bus-mastering VLB slot, so I tend to think the
motherboard DMA may be broken.
Nothing in the 445C docs said it needed a bus-mastering VLB slot - how
do I tell if my MB has one, and which one slot it might be?
The very first sentence in my 445C manual mentions that it is a bus-mastering
controller, though the need for a bus-mastering slot is left as an exercise to
the reader.
Ideally, your motherboard manual should document this, but few of them seem to.
My Genoa TurboExpress 486 motherboard has a manual that's comparatively quite
good, but it still omits this vital info. Typically, the slots closest to the
CPU socket are the bus-mastering ones. The SiS 471 chipset in my Genoa
motherboard only supports two bus-mastering slots even though there are three
VLB slots total; I identified the bus-mastering slots by trying the 445C in
each one in turn and seeing if the system booted successfully (I know that the
SiS 471 chipset only supports two such slots).
Leonard
