> At 10:40 AM -0500 1/7/00, Allen Briggs wrote:
> > One of the issues was dedicated to 6502/8502 assembly/machine
> >code and had an article or two on the undocumented instructions (mostly
> >formed by figuring out which bits drove which functions and finding
> >"unused" combinations).
> Ah, the days before "illegal instruction trap" :-)

Yup.  You could totally wedge the processor, too, I think.

> >Do you have code that can be integrated so that other people might be
> >able to pound on it some and help out?  Is it basically functional for
> >some models?
> 
> Unfortunately, everything is in sort of a "pile". I have a thousand
> snippets of code, test programs, annoted ROM disassemblies, and a huge
> folder full of information, specs, notes, and little tiny slips of paper
> with offsets, bitfield guesses, etc.

<grin>  Well, I know how that goes, but it would be Really Cool /
Totally Rad / Most Awesome / etc., if you could find some time to digest
at least some of it for others.

> The guts of the drivers tend to conern me less. These are trivial pieces of
> code if I'm just doing monitor probing and DAC support.

Trivial pieces of code that people could be using to get color X on
their internal video devices...  :-)

> This is why I'm glad we now have wscons since I believe it takes us a step
> closer to a better API and internal framework for graphics.

Definitely.  I like the idea that we might be eventually in the position
of having a unified API across all architectures.  Kudos to Scott for
working on this for the mac68k!

> I know I have to sync with the vertical retrace but I've
> been having trouble since the interrupt handler needs to write a location
> and then the driver needs to poll that location and I'm not sure that's
> something that's germain to the NetBSD device model.

Do you want to do it that way, or install an interrupt handler for the
video (which is already there, right?), and have it test to see if there
is any work to do (i.e., reload the palette)?  I'd be happy to fool some
with this if I had the rest of the code.  :-)

> This is why I'd like to go "back to basics" and just write the smallest set
> of stuff I can write for all machines and submit that. That gives me a
> springboard to work off of. When I come back at the code for a second pass
> I can concentrate on less mundane problems.

I'd be happy with stuff that isn't quite "the smallest and/or cleanest"
that other people can work on -- probably with you answering some
questions.  Ideally, you could write a treatise on the mac video.  For
the NetBSD/mac68k web site--or an article for DaemonNews or some such.

> Stay tuned. I've been feeling lucky since I got linux back up on my
> PowerMac again :-)

:-)  Cool!

-allen