From:	DavMac AT iname DOT com (Davin McCall)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: mem to mem DMA transfer
Date:	Mon, 14 Jun 1999 11:45:54 GMT
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A while ago, I was trying to find info about doing this myself. I
scanned documents from the web, found something that looked
interesting, contacted the author and they told me they'd given up
trying as it isn't the most efficient way to copy memory anyway (if
memory reads/writes are being done, it's still taking up processor
time: you might as well just do it in the conventional way).

I also remember reading that the DMA chip itself is capable of
mem-to-mem transfers, but in the PC the wiring makes this impossible.

In any case, I never managed to do it.

Davin.

On Mon, 14 Jun 1999 08:37:34 +0200, "Max Breganze"
<max AT target33 DOT 8m DOT com> wrote:

>Do you think it's possible doing a DMA transfer from system mem to video mem
>leaving the CPU free of doing something else in the meanwhile?
>Some time ago I heard about this possibility for the screen update, but
>someone said it's useless for many reason I don't remember.
>Do you think it's possible and useful?
>Please, give me your opinion and maybe some useful information about it.

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