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Re: Let's pay a developer to make a VGA output card



js@cimmeri.com wrote:
> Alex Freed wrote:
>> S-video is only different from composit video in one respect - the color
>> information comes on a different wire than the luminance. The way video
>> is generated in apple 2, they are inherently mixed. So it doesn't matter
>> much if you try to separate them at the computer side rather than inside
>> the TV. A modern TV will likely do a better job with a comb filter.
> 
>    The Apple II/+ was designed for composite or RF, and likely would
> best be utilized there forever.   But, looking at the schematics for
> the Apple IIgs, I found that they used an MC1377 Color Television to
> Pal/NTSC encoder chip after the VGC.    The VGC supplies RGB+Comp/Syn
> to the RGB connector directly, and also supplies the MC1377 for
> eventual composite video output.
> 
>    Looking at the specs for the MC1377, there is revealed some circuit
> mods to allow this same chip provide S-Video!   The specs also discuss
> the comb filter idea mentioned by Alex above.  But, the s-video sounds
> like a very interesting prospect.    S-Video on my vid equipment is
> significantly better than composite.   Does anyone have a feel if it
> would be adequate for 80col display?
> 
>      My aim here with all the VGA stuff is not to get VGA resolution,
> but rather, to find a monitor that will work with the GS down the road,
> after these 1986-1988 RGB monitors die.   Prospects look dim so far.
> Hooking up the IIGS to even my composite input LCD TV, produces
> horrible results.   CRTs seem best.   CRTs made now use S-Video.
> 
> ~ J
> 
Why not just get all the video information from ram / softswitches and
generate VGA signal on the card?

V/R
Mark Frischknecht

-- 
si vis pacem, para bellum
http://www.appleiiguy.net
Apple ][ Forever!

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