Xref: utzoo comp.dcom.lans:5819 comp.os.os2.programmer:75 comp.os.msdos.programmer:720 comp.sys.ibm.pc.hardware:1269
Path: utzoo!utgpu!news-server.csri.toronto.edu!torsqnt!tmsoft!mshiels
From: mshiels@tmsoft.uucp (Michael A. Shiels)
Newsgroups: comp.dcom.lans,comp.os.os2.programmer,comp.os.msdos.programmer,comp.sys.ibm.pc.hardware
Subject: ISA Bus master cards and 80386+ Virtual 8086 mode
Message-ID: <jdrjb2csq@tmsoft.uucp>
Date: 31 Aug 90 02:37:14 GMT
Reply-To: mshiels@tmsoft.UUCP (Michael A. Shiels)
Followup-To: comp.dcom.lans
Organization: MaS Network Software and Consulting
Lines: 9


How do the multitudes of Bus master cards out there (Madge, Proteon etc)
handle something like QEMM 386 filling in the area from A000-B800 on a CGA
system so that you have ~90K more space for DOS.  The problem is this memory
is not actually at that address for the Bus master card to read it.

I have heard of something called the VDS (Virtual DMA Specifications) which
is part of the PS/2 BIOS to allow Bus Mastering on MCA machines.  Does the same
thing work/exist for ISA machines?