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From: wahlsten@elixir.lne.kth.se (Jorgen Wahlsten)
Newsgroups: comp.os.msdos.programmer
Subject: Re: DMA questions.
Message-ID: <1991Feb23.013210.16165@kth.se>
Date: 23 Feb 91 01:32:10 GMT
References: <8bl2yqS00WB401Skhj@andrew.cmu.edu>
Organization: Dept. of EE, Royal Institute of Technology, Stockholm, Sweden
Lines: 11

In article <8bl2yqS00WB401Skhj@andrew.cmu.edu> ps2x+@andrew.cmu.edu (Peter John Skelly) writes:
>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.

With a PC it will be hard... There is only four DMA-channels (0 to 3)
and one can only use DMA-channels 0 and 1 (together) to do memory to
memory copies. Unfortunatly they are already used to do memory-refresh...

But isn't it two DMA-chips inside an AT ?!? If so one would be able to
use DMA-channels 0 and 1 in the second DMA.