On Thu, 12 Feb 1998, Ken Nakata wrote:
> When I stopped by at Allen's house last weekend, he told me that Dave
> (Huang?) was working on esp driver that uses DMA on Q840AV.
> 
> As I'm now an 840AV owner as well, I'm very interested in how things
> are coming out.  Any word on it yet?

Hi :) I'm planning on working on it, but I've been busy and haven't
actually gotten anywhere yet. The first thing I was going to do was
implement the bus_dma(9) interface (and get the MACE driver to use it).
Hopefully, that'd provide a nice framework for the other DMA things (SCSI,
serial, sound, whatever else :)

> Also, I'd like to get my hands on whatever technical documentation
> available on the custom chips on board, i.e. CIVIC, Endeavor, VDC,
> Sebastian, etc.  It would be really cool to be able to run X server on
> this machine in 16-bit or 24-bit color depth.

I put what little info I could find on the PSC's DMA engine in
mac68k/psc.c and psc.h. Some examples of how to use it are in
dev/if_mc_obio.c. Basically, you set some magic bits in some control
registers, load in the physical address and length of your buffer, then
set some other magic bit to make it go. At least that's how it works for
the ethernet; I haven't looked at anything else yet.
-- 
Name: Dave Huang     |   Mammal, mammal / their names are called /
INet: khym@bga.com   |   they raise a paw / the bat, the cat /
FurryMUCK: Dahan     |   dolphin and dog / koala bear and hog -- TMBG
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