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From: jerry@gumby.Altos.COM (Jerry Gardner)
Newsgroups: comp.windows.ms
Subject: Re: 386 Enhanced Problem.
Message-ID: <4737@gumby.Altos.COM>
Date: 26 Mar 91 18:53:40 GMT
References: <77.27DF83E0@bohemia.metronet.org> <13479@helios.TAMU.EDU>
Reply-To: jerry@altos.COM (Jerry Gardner)
Organization: Altos Computer Systems, San Jose, CA
Lines: 29

BE> Why is it that I can run Windows in Real and Standard Mode, but not 386
BE> Enhanced?  My system is a 25MHz 386, 84MB SCSI HD, 2 MB Ram, QEMM 5.11.
BE> Every time I try to run in Enhanced Mode, I get Disk Read Error, Abort
BE> Ignore Retry Fail.  The other modes work just fine!  Also, anybody out
BE> there have docs on the Seagate ST-01 card?  Mine didn't come with them.


The problem is probably your SCSI controller.  If it's a DMA bus master,
it will thoroughly confuse Windows when it tries to start up in 386 mode.

The reason for the confusion is as follows:  when the 386 is remapping
memory to different physical addresses, it doesn't correctly pass this
information along to bus masters.  The SCSI controller will take a virtual
address and use it to do DMA.  Unfortunately, this address may not point
to the correct address in physical memory.

The solution is to use a device driver with your SCSI board that supports
the VDS standard (Virtual DMA Services).  Both Windows 3.0 and QEMM 5.1
support VDS directly.  Adaptec has a driver for its controllers called
aspi4dos.sys.  

If you can't get an appropriate driver, try using smartdrv with the /B 
parameter.

-- 
Jerry Gardner, NJ6A					Altos Computer Systems
UUCP: {sun|pyramid|sco|amdahl|uunet}!altos!jerry	2641 Orchard Parkway
Internet: jerry@altos.com				San Jose, CA  95134
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