Subject: Re: scsi info

From: [email-masked] (Niklas Hallqvist)

>>>>> "Tim" == Tim Newsham <[email-masked]> writes:

Tim> Hi, I will probably be writing a scsi driver for GVP-series II
Tim> scsi cards soon.  I have never written a SCSI driver before.
Tim> What is a good source of information for SCSI in general and
Tim> GVP's hardware in particular?

The draft SCSI-2 spec is available on the net.  Note this is a draft,
the final spec you'll have to write to ANSI and pay for.  However these
documents have helped me alot gaining understanding about SCSI issues.
I no longer remember where I got them, and if noone else knows and
speaks up, I could mail them to you.

GVP is another issue.  AFAIK, I'm the only one who've produced any
doc on it.  GVP themselves has never been very helpful with technical
info.  I had to read gvpscsi.device myself to get that info.  Anyway
the chip GVP uses is well documented (33C93) and manufactured by both
WD and AMD.  Both to me and Markus Wild, AMD has been very helpful in
their respective national offices.  I suggest you call your local AMD
representative explaining you're doing and most likely they will send
you the databook for free.  I can not find my databook right now, as it
is packed in some box since we moved this summer.  Maybe Markus can
provide you with your local representatives phone no.

Regarding the GVP DMA I did produce a small text file at that time.
Since then I have had a disk crash from which I never completely
recovered.  It's very possible I may have the doc on another computer
or on a tape somewhere, but I can not promise anything.  However
I did send this doc to someone, I think he used it to write a Minix
driver.  Does someone on this list know who made the Minix GVP driver,
if there is one, that is?  However you might as well read gtsc.c,
the DMAC isn't very complicated.  It's even simpler than the A2091 &
A3000 DMACs.  It's almost just an address register and a start/stop
toggle if I remembered things correctly.

Get back to me if you get any problems or have further questions.

Niklas