Path: utzoo!attcan!uunet!dino!uxc.cso.uiuc.edu!csd4.milw.wisc.edu!srcsip!jhereg!dab
From: dab@jhereg.Minnetech.MN.ORG (David A. Bright)
Newsgroups: comp.unix.microport
Subject: Help on System V/AT DMA needed
Message-ID: <32@jhereg.Minnetech.MN.ORG>
Date: 21 Jul 89 21:38:59 GMT
Reply-To: dab@jhereg.minnetech.mn.org.UUCP (David A. Bright)
Distribution: na
Organization: Minnetech Consulting, Inc., Mpls, MN
Lines: 19

I have been trying to write a device driver for a tape drive under System V/AT,
but can't seem to get DMA to work.  When I initiate data transfer, it doesn't
seem to work (I get an error indication from the tape drive); sometimes the
residual count is non-zero, sometimes it isn't.  I don't know exactly what is
the problem (from the drive's perspective), because to get extended status, I
need to do DMA (Catch-22!).  The documentation from Microport on writing device
drivers is, to say the least, sketchy.  Any help would be greatly appreciated.

--
David A. Bright
910 W. Burke Avenue		dab@Bright.MN.ORG	(Home)
Roseville, MN  55113		
612 487-2407 (Voice)		612 487-2416 (Data)

-- 
David A. Bright
910 W. Burke Avenue		dab@Bright.MN.ORG	(Home)
Roseville, MN  55113		
612 487-2407 (Voice)		612 487-2416 (Data)