Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!tut.cis.ohio-state.edu!sei!fs7.ece.cmu.edu!o.gp.cs.cmu.edu!netnews From: Ralf.Brown@B.GP.CS.CMU.EDU Newsgroups: comp.os.msdos.programmer Subject: Re: DMA questions. Message-ID: <27c52136@ralf> Date: 22 Feb 91 12:48:38 GMT Sender: netnews@cs.cmu.edu (USENET News Group Software) Organization: Carnegie Mellon University School of Computer Science Lines: 15 In-Reply-To: <8bl2yqS00WB401Skhj@andrew.cmu.edu> In article <8bl2yqS00WB401Skhj@andrew.cmu.edu>, Peter John Skelly wrote: }Does anyone know if it is possible to program the dma chip used in pc's to }do memory to memory copies. I've heard both ways, but if someone knows for }sure either way, I'd like to know. } }If it is possible, some suggestions on how would be useful. My understanding is that memory-memory DMA is only possible using channels 0 and 1, and channel 0 is used for DRAM refresh. That would make things rather tricky even if possible at all. -- {backbone}!cs.cmu.edu!ralf ARPA: RALF@CS.CMU.EDU FIDO: Ralf Brown 1:129/3.1 BITnet: RALF%CS.CMU.EDU@CMUCCVMA AT&Tnet: (412)268-3053 (school) FAX: ask DISCLAIMER? Did | It isn't what we don't know that gives us trouble, it's I claim something?| what we know that ain't so. --Will Rogers