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Mail Archives: djgpp/1996/02/10/18:36:50

Xref: news2.mv.net comp.os.msdos.djgpp:940
From: ulfg AT groundhog DOT phy DOT nist DOT gov (Ulf Griesmann)
Newsgroups: comp.os.msdos.djgpp
Subject: how to allocate DMA pages ?
Date: 10 Feb 1996 20:59:53 GMT
Organization: NIST
Lines: 18
Message-ID: <4fj109$o5f@dove.nist.gov>
NNTP-Posting-Host: groundhog.phy.nist.gov
Summary: [Q] allocating DMA pages with DJGPP
Keywords: DMA pages and DJGPP
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

Hello All,

The 8237 DMA controllers in a PC can only perform DMA transfers to the 
lower 16MB of physical memory. This makes it awkward to allocate 
buffers for DMA transfers on machines with >16MB of memory because a 
simple 'malloc' is no longer guaranteed to allocate DMAable memory.
Does anyone out there know of a good strategy for allocating DMA buffers 
which works on large memory machines ? (Will take source code...)

Thank you,
  Ulf

-- 
  Ulf Griesmann                       \\\   Tel.: (301) 975 3212 (x73220)
  National Institute of                \\\   Fax.: (301) 990 1350
  Standards & Technology                \\\   e-mail:
  Atomic Physics Division, Bld. 221/A167 \\\   ulfg AT groundhog DOT phy DOT nist DOT gov
  Gaithersburg MD 20899, U.S.A.           \\\   ulfg AT aeldata DOT phy DOT nist DOT gov 

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