Composite Video mod, lift two pins on the TIA?

[Pipercub]

OK, I did the composite mod to my 2600 and it works great, two RCA females on the back and it is all tied into my 6 way switcher with the other classic video game systems. I have all that fed into the input on my PC and life is good.

 

I have noticed on a few games a strange distortion where a small section of the screen may be out of alignment. Clearly RF issues are not present. I did read in a few mod descriptions and how to-s that someone discovered that if you lift two pins on the TIA those problems go away. It further mentioned that Atari had these problems when they were using composite to demo the units trying to avoid RF problems. NATURALLY, the two pins are never named.

 

Anyone know what two pins are being refered to? And more importantly, why?

[cwilkson]

I'm pretty sure you're talking about the mod I did for Glenn Saunders when he was producing the Stella at 20 videos. I don't remember which pins I lifted, but probably only the color pin....PIN 9.

 

Glenn, can you help answer this? Do you remember what I told you?

 

This isn't necessary for most mods. If you're not sure which pins to lift, you're probably not going to gain much by doing it. Actually, I'm not sure how much you gain by doing it, even if you know why you want to.

 

In short...I wouldn't recommend it. Don't bother.

 

-Chris

[cwilkson]

Reading your post again, if you are having alignment issues, with only a small part of the screen, it's probably internal to the TIA chip. If that's the case, there isn't much that can be done about it

 

Can you post an annotated screenshot? If you can point out the particular problem that you're seeing, I can probably tell you what's causing it and how to fix it.

 

-Chris

[Pipercub]

Sweet, will do tonight when I get home. It only does it on some games. So I will snap a few.