From: Charles Sandmann <sandmann AT clio DOT rice DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Using UDMA with DJGPP
Date: Sun, 29 Jun 2003 16:49:54 CDT
Organization: Rice University, Houston, TX
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> I want to use UDMA, but I don't know how to get the physical address of
> the buffer I allocate for that purpose

It all depends on the environment you plan to run with - if you are under
DOS then you can use techniques which are DPMI provider specific to get
the physical address.  Under CWSDPMI you can query the page tables, see:

  http://clio.rice.edu/djgpp/cwsdma2.zip

under PMODE, if EMM386 isn't loaded then paging isn't turned on, and it's
a really easy calculation.