Capcom CPS1 Digital RGB Out

[Bibin]

In trying to fix my CPS1's fried (literally!) DAC circuitry, I stumbled across the digital RGB pins here:

This all came from here.

http://mikejmoffitt.com/wp/?p=77

 

[Mr. Hooker]

I'm guessing the ??? is for the black & white / grey scale.

 

[Bibin]

Yeah, I didn't know it did greyscale output. What's the point of that?

 

[Mr. Hooker]

Sin City, the Andy Griffith show, that sudden flashback scene, this page, or just normal grey scale shadowing used in everything.

 

[Bibin]

What? What in the world are you talking about? There is no reason to have a dedicated greyscale channel when you have discrete RGB.

 

[Mr. Hooker]

meh, was worth a shot. get it working then cut the traces on the ??? lines to find out.

 

[Bibin]

The mod is finished.

 

[superben51]

Did you wire up the gray scale?

 

[ttsgeb]

*looks at breadboard*
*looks at thread*
*sees THREE channels worth of DACs built*

Did you wire up the gray scale?

So have you tried doing anything with that fourth set of pins to see what it is?
It doesn't look to be redundant, and it doesn't look like a NC, so I'm kinda curious.
Like you said, a greyscale channel would make little sense, but if that's what it is; it's pretty neat.

edit: read this
Now I see what's going on... That's pretty neat, actually. You should replace it and find a way to hook up a spotlight or something to it as well.