Re: cine -> wg adapter

> >So how does the Color Card interpret the 12-bit color data it get from the
> >CPU ??? This has been bugging me (no pun intended) for some time.
>
> Zonn's latest hardware description talks a bit about the color conversion.
> Since I have to do clipping now, looks like i'm just going to implement
> the whole thing now with a uP and two DACs, and do the whole thing in
> software. It does have the advantage that you can use it as a test pattern
> generator, too :-)
>
> My current thought is to have two 12 bit input ports, and have the uP
> watch the state of the start, end signals and an intensity port.
>
> One thing I was wondering, Zonn, is if the 12 bit start/end values are
> ever not at the endpoints of the vector being drawn. Do they ever
> send endpoint data farther out than the actual line end, and use the
> line timer to clip to the visible endpoint.

Every line is drawn by extending the end-point beyond the place where the
beam stops. Larry Rosenthal actually pattented the technique. Timing is
critical to turn off the beam and the analog switches to stop the beam,
that's the whole purpose of the line timer. It's kinda funny to know that
even those short lines that make up the ships in Space War are extended
to a length comparable to the monitor size and then stopped before they
draw too much...

If you're going to put a processor in there, why not run an emulator on
it and replace ALL the cinematronics hardware :-)

BTW, if Larrys pattents are not on the web, I could get Frank to scan
my copies in ;-)

--
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|   \ /  \ | | | || |       phkahler@oakland.edu     Engineer/Programmer
|  _/| || || |_| || |__     " What makes someone care so much?
|_|  |_||_| \___/ |____)      for things another man can just ignore. " -S.H.