Xref: news-dnh.mv.net comp.os.msdos.djgpp:3734 Path: news-dnh.mv.net!mv!news.sprintlink.net!newsfeed.internetmci.com!info.ucla.edu!nntp.club.cc.cmu.edu!cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!oitnews.harvard.edu!newsfeed.rice.edu!rice!news!sandmann From: Charles Sandmann Newsgroups: comp.os.msdos.djgpp Subject: Re: Getting the physical address of allocated virtual memory Date: Sat, 09 Dec 1995 10:55:01 CST Organization: Rice University, Houston, Texas Lines: 11 References: Reply-To: sandmann AT clio DOT rice DOT edu Nntp-Posting-Host: clio.rice.edu To: djgpp AT sun DOT soe DOT clarkson DOT edu Dj-Gateway: from newsgroup comp.os.msdos.djgpp > These cards use DMA to transfer data to and from the PC's memory, and > therefore require to know the physical address of the data. The full > configuration will require between 1 and 3Mb of data transfer area! Putting DMA buffers outside of the 640K area is a non-trivial task. If you know you are going to be working under a single environment (like CWSDPMI) then there are some specific things which can be done to get this information. In general, you need to look at the VDS specification which describes the various options for this support. But I know CWSDPMI doesn't support VDS itself (it might layered under the appropriate VCPI). This is really a messy area, but it can be solved with some work.