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From: wlsmith@valve.heart.rri.uwo.ca (Wayne Smith)
Subject: Re: IDE vs SCSI
Organization: The John P. Robarts Research Institute, London, Ontario
Date: Mon, 19 Apr 1993 03:52:29 GMT
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In article <1993Apr18.035941.14697@grebyn.com> richk@grebyn.com (Richard Krehbiel) writes:
>
>Heck, if IDE used DMA, then you'd hear all kinds of complaints about
>ISA bus systems with more than 16M RAM not working with their IDE
>drives.  16M is the DMA addressing limit of the ISA bus, and if IDE
>did DMA there would be trouble.

There would be no problems as long as the OS didn't set up a DMA transfer
to an area above the 16 mb area (the DMA controller probably can't be
programmed that way anyways, so there probably isin't a problem with this)

Besides, like I said before, the FDD controller uses DMA channel #2.
And I don't yet believe that the HDD controllers (any of them, MFM, RLL,
etc) don't also use DMA.

