Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!evax!utacfd!merch!cpe!adaptex!adaptx1!neese
From: neese@adaptx1.UUCP
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: QEMM and SCSI host adaptors
Message-ID: <284500009@adaptx1>
Date: 5 Jan 91 05:55:14 GMT
References: <2262@bhpmrl.oz.au>
Lines: 37
Nf-ID: #R:bhpmrl.oz.au:2262:adaptx1:284500009:000:1890
Nf-From: adaptx1.UUCP!neese    Jan  4 16:16:00 1991


>/* ---------- "Re: QEMM and SCSI host adaptors" ---------- */
>Ive been running QEMM 5.1 on my 386 for a couple of months now, using
>win3, Quattro Pro etc etc with no problems at all. I havent tried WP5.1
>but WP5 works OK. So I canUt really understand the complaints about
>QEMM 5.1 + QPRO + WP5.1.
>
>However, I have recently been trying to get a @#$% Adeptec SCSI adaptor
>to work, with absolutely no success, and I didnt think to suspect QEMM.
>Ill test the hypothesis ... and follow up this posting if ive anything
>interesting to add.

It isn't the adapter as much as it is the environment it is in.  The
adapter is a bus master and as such requires physical addresses to do its
job correctly.  When running Win30/QEMM or any such utility/program
that puts the 386 into virtual mode, the memory addresses are all logical
and no longer physical.  The adapter has no way to determine this and
even if it could it has no way to get the physical address from the 386
processor as those registers are protected and are under the control of
the application.
However, this is becoming all a rather mute point.  There are many ways to
have a bus master peacefully coexist in this environment.  With QEMM v5.0
and later a command line option of /DB:16 allows bus masters to be happy.
With Win 3.0 and later, you can use SMARTDRV.SYS to make it all work.

Or, this is Adaptec specific as I don't know the state of any other products,
you can use the ASW-1410 v2.0 or later driver available through distribution
that has VDS support.  This support is in Win 3.0 as well as QEMM v5.0
and later versions of both.  This solves the problems associated with
running a bus master in a virtual memory environment.

			Roy Neese
			Adaptec Senior SCSI Applications Engineer
			UUCP @  neese@adaptex
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