4-switcher A/V mod?

[ubersaurus]

I was wondering how do you mod the 4-switcher correctly? The description in the faq is kinda vague.

[ubersaurus]

any help on this one?

[Alex]

This raises a good point. I think it's high time someone makes a very detailed, very clear tutorial on modding a 2600 for composite output. Made for newbies, not other engineers. Other engineers don't need a guide. With lots of nice, high quality pictures. Anyone looking for a useful project?

[Albert]

At CGE2K1 this year, Chad Schell was using a 2600 Jr. with an S-Video modification by Chris Wilkson. It's a small board that appears to piggyback onto an existing chip (I don't know if the 2600 Jr.'s chips are socketed), with audio and video jacks right on the board. I believe Chris has plans to make this mod available at some point in the future, but I don't know for sure.

 

If I could get s-video output out of a 2600 Jr. I'd be quite happy, especially when coupled with a Cuttle Cart.

 

..Al

[ubersaurus]

Well, my friend is in his 2nd year in electronics, and Although he could read the schematics, they aren't good enough for him to figure out the video. We got a really crappy picture, but that just isn't good enough to do much of anything. This atari is a little project of ours. It had a few things wrong with it, such as the busted controller port, which we've repaired, and this is the last thing we want to do to it.

[jsoper]

The video mods in the FAQ aren't that bad, I've built them. The chroma/luma (S-video) one is the best, it looks incredible. If you only want composite video, just run the 6.8k resistor to the same point as the luma lines, not into its own transistor.

 

I think two of the luma resistors should be swapped, it's been awhile. The three luma resistors values should increase in the same order as the three resistors on the board.

 

The audio mixer needs to be opened to have a sharp picture. I usually cut the Q201 transistor base and bend it up. That way, you can solder it back together later if needed.

 

If you're still having trouble, run all the signals to a protoboard and stuff the circuit there. You only need sync and one luma to get a black and white picture. Then you can add the other lumas, chroma, and audio.

 

Last option, print out the schematics and instructions, buy the components, and take it all to a small tv/vcr repair shop and see if they'll do it for a reasonable price.

 

DISCLAIMER: I am an engineer

John

[jsoper]

Oh yeah, you can leave out that 4050 buffer. A 4-switcher still looks good without it. The 6-switchers and 2600jrs already have a 4050 on board, so you might as well take the signals from it.

 

John