[Coco] Re: S-video Prospects...

Roger Merchberger zmerch at 30below.com
Sat Dec 17 16:46:28 EST 2005

Rumor has it that Torsten Dittel may have mentioned these words:
> > Also, according to the manual, the GIME chip in the NTSC & PAL CoCo3s are
> > the exact same chip; so saying that chroma & luma are generated totally
> > internally on the NTSC CoCo3, whilst true, seems to be also true of the PAL
> > CoCo3 as well...
>AFAIR the corresponding pin of the GIME isn't connected on the PAL

What I'm saying is this: Some people (as I understood it) were saying that 
Chroma & Luma were available on the PAL CoCo3, but not on the NTSC CoCo3 
due to those signals solely being internal to the NTSC GIME. Yet, the GIME 
is the same between both machines. Therefore, I think the GIME has nothing 
to do with it.

Can you get Chroma & Luma on a PAL CoCo3 that *doesn't* have the PAL 
daughterboard? My hypothesis is: "No." I think that the PAL daughterboard 
is generating Chroma & Luma from the RGB signals, and as such, with a 
similar daughterboard with crystals for NTSC frequencies, S-Video is a 
viable possibility, assuming there's a source for said boards.

I have the schematic & artwork for the boards, and if the 3 ICs necessary 
are available, it might just be a matter of getting some built.

>Why not create a daughterboard with Roy's VGA design?

I'm not trying to generate VGA (which is an analog RGB design just at 2x 
frequency from NTSC, not Chroma/Luma); my Sony TV doesn't have a VGA port 
on it.... and those of us in the US don't have sets with SCART ports on 
them, either. :-/

I don't have anything against Roy's design, but at this point it's not 
going to enable me to do what I want with my CoCo3. I'd like to have more 
options available, and S-Video seems to me like the best way *for me* for 
better display options.

Since when is it bad to have *more* options? ;-)

Roger "Merch" Merchberger

Roger "Merch" Merchberger   | "Bugs of a feather flock together."
sysadmin, Iceberg Computers |           Russell Nelson
zmerch at 30below.com          |

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