S-video mod?

Retromaster · Post by **Retromaster** » Sat Feb 17, 2007 9:04 pm

is there a guide to modding the atari 2600 4-switch to outputting S-video?

this is one of my last posts before I leave benheck for a while.

vskid · Post by **vskid** » Sat Feb 17, 2007 9:13 pm

Wait, since when were you here:

south carolina- the land of semi-old people...right next to shockslayer...SAVING THE WORLD....

I thought you lived in Florida.
Did you check Ben composite mod? It might say if you can.

Retromaster · Post by **Retromaster** » Sat Feb 17, 2007 9:18 pm

I changed that for shockslayer.
I wanted something different.
I was reading through the composite video mod guide and didn't really find anything......
lemme check again.

Post by **bicostp** » Sat Feb 17, 2007 9:30 pm

Do the composite mod, but don't combine the signals. They're your luma and chroma signals for S-video.

Retromaster · Post by **Retromaster** » Sat Feb 17, 2007 9:33 pm

OK. is luma and chroma a certain pin on the ICs?

EDIT: or are they audio and video?

vskid · Post by **vskid** » Sat Feb 17, 2007 9:45 pm

Retromaster wrote:OK. is luma and chroma a certain pin on the ICs?

EDIT: or are they audio and video?

Its the video signals, they form composite when put together in the same wire, S-video when separate (I think). I bet you get the signal from the pins of an IC, don't ask which, I don't know.

Retromaster · Post by **Retromaster** » Sat Feb 17, 2007 9:50 pm

alright, off to the schematics I go.
I want to avoid putting +5 volts in the wrong place, so if any of you have a pinout or something, that would be great....

mean boss from the movie office space wrote:....yyyeeeaaahhh....if you could come in this weekend that would be greeeeaaaattt.........

Ditto · Post by **Ditto** » Sat Feb 17, 2007 10:53 pm

Here is a rundown for you retro....

Composite video is Croma (what colour somthing is) and luma ( how bright) tied together.

S-Video is simply composite video with croma and luma not tied together.

D

Retromaster · Post by **Retromaster** » Sat Feb 17, 2007 10:57 pm

what you said helped a lot.

does anyone have a pinout with chroma and luma labled?
I NNNEEEEDDDSSS me a way!

Gump-in-space · Post by **Gump-in-space** » Sat Feb 17, 2007 11:57 pm

I just read somethin like this at another forum, and let me put it to you this way. "The difference in quality is only there if the GPU/PPU outputs the signal in that format. That's why S-video on the Atari wouldn't be better if you just split the signal. You need to actually output the S-video signal. This is also why most LaserDisc players S-video, while great at the time, is actually worse than what you can do with a TV's comb filter and the composite connection, as the S-video output was simply composite that was split and comb filtered, in no specific order."

If you are are looking for crisper video quality, this is probably not the way to go.

Retromaster · Post by **Retromaster** » Sun Feb 18, 2007 12:08 am

well....I wasn't really going to DO it....I was just gathering info for atari2600a. i'm a moderator on his website (the one in my sig)
and he was saying that it was possible to do. I was just wondering how.
I'm doin' a composite video mod anyway because my rf box is bad (i think).

thanks people, but dont lock this yet because I still need a pinout or something.....

atari2600a · Post by **atari2600a** » Sun Feb 18, 2007 12:16 am

Gump, the Atari's Stella GPU outputs S-video virtually natively. Think about it, Stella doesn't create a composite signal so that it can hog up more silicon to split it up into 4 seperate signals.

LaserDiscs are a different story. LaserDiscs are a composite format; there's already dotcrawl & bleeding on the disc itself.

Post by **bicostp** » Sun Feb 18, 2007 9:49 am

<img src="http://img264.imageshack.us/img264/7936/duhxh0.png">

This is the diagram of the old 4-switch Composite mod, modified to have the two signals seperate. Do this and you should have S-video. (Refer to the 4-switch mod instructions in the sticky for a complete rundown.)

jeroen · Post by **jeroen** » Sun Feb 18, 2007 10:11 am

Btw. I think i've read that to combine chroma/luma you have to use a cap. But that doesn't apply for s-video of course since your not combining them.

Retromaster · Post by **Retromaster** » Sun Feb 18, 2007 10:44 am

bicostp wrote:<img src="http://img264.imageshack.us/img264/7936/duhxh0.png">

This is the diagram of the old 4-switch Composite mod, modified to have the two signals seperate. Do this and you should have S-video. (Refer to the 4-switch mod instructions in the sticky for a complete rundown.)

do you happen to know what pin chroma is?

also, what IC is this? describe.

jeroen wrote:Btw. I think i've read that to combine chroma/luma you have to use a cap. But that doesn't apply for s-video of course since your not combining them.

what uf? (if I happen to do that....)