Re: Just my 2 penny worth..

[Michael Schwingen <rincewind@tubul.dascon.de>]

On Tue, Jun 23, 1998 at 03:30:26PM -0400, Martin-Eric Racine wrote:
> NOTE:  The TT allows direct access to TT-Ram using DMA, so Steve's
>        idea that HD-drivers should be able to perform faster on 
>        the TT is correct (this only works on the SCSI bus, however;
>        ACSI is still blocking non-DMA, AFAIK).       

I am quite sure that at least HDDriver and CBHD *do* SCSI DMA direct to
TT-RAM on a TT, so I see no way of improving this.

ACSI is DMA (non-blocking when using Magic!) when going to ST-RAM, and is
copied via _FRB to TT-RAM.

>        The Falcon is far more limited over this aspect, as it's 100%
>        ST-ram based. ask Sven or Uwe Seimet, there's been plenty of 
>        details about this, over this mailing list and on newsgroups.

Not quite. The Falcon *can* do Blitter and SCSI/Sound-DMA accesses to
Fastram on the 16-bit CPU Bus - eg. on Magnum/F030 cards.

cu
Michael
-- 
Michael Schwingen, Ahornstrasse 36, 52074 Aachen