NTSC/PAL variations on composite mod?

[Wayne Venomous]

I've just modded my 2600 Jr (UK market PAL version) to run composite video (Ben Heck's old version at http://benheck.com/phpBB/viewtopic.php?t=1154 not too keen on snipping out resistors just yet!) and although the chroma and audio points are very different, I've managed to trace them.

However, even though I've soldered in the correct resistor and pots and double checked all the connections, I can't seem to get the colours right. For example in Pac Man, Pac Man is very orange, the maze is red and the background is dark blue.

I'm wondering if this is because the original mod is based on an NTSC machine? I'm also wondering if that means if I put in an NTSC cartridge, the colours would be correct? (I've heard colours are a bit weird if you play an NTSC cartridge on a PAL machine and vice versa)

Any ideas?

BTW, I've noticed in my PAL Atari six switcher, the RF section has a whole circuit board soldered over where the NTSC components would normally go - any tips for getting composite out of this? I figured I'd experiment with my 2600 Jr first but I'm starting to think about leaving the six switcher well alone.

[jeroen]

Adjust the potentiometers until the video looks right. Use a game like Pitfall that has a lot of color for a good calibration.

[Wayne Venomous]

Been messing with the mod for nearly a day now, those colours aren't gonna be right no matter how much I adjust the potentiometers. I've tried Pitfall, I was just using Pac Man as an example.

Has anyone attempted this on a PAL machine?

[radfoo]

yes, NTSC and PAL mods are different. I have been told Bens new mod should work, but I had no luck with it.

This is my old mod from 2002 that works sort of ok (look for www . itstoast.co.uk/atari/palav2.htm on wayback machine). It the same as the one you have done but connect the following pins instead

2. centre of phono
5. 1k pot
6. centre of phono
7. 1k resistor

Audio and chroma the same as you have already found.

I think I have found another mod that connects to the 4050 chip, but I need to test it properly.

[Wayne Venomous]

yes, NTSC and PAL mods are different. I have been told Bens new mod should work, but I had no luck with it.

This is my old mod from 2002 that works sort of ok (look for www . itstoast.co.uk/atari/palav2.htm on wayback machine). It the same as the one you have done but connect the following pins instead

2. centre of phono
5. 1k pot
6. centre of phono
7. 1k resistor

Audio and chroma the same as you have already found.

I think I have found another mod that connects to the 4050 chip, but I need to test it properly.

AHA! That's looking a lot better, thanks!

Hmm..... gonna have to try the original mod with an NTSC cartridge and see if the colours are correct and if so maybe put in a PAL/NTSC switch. Need to get an NTSC cart first though - I love Ebay!

[radfoo]

Pleased it worked

I would be interested to know if your NTSC cart works. Please post a message back when you try it.

[Wayne Venomous]

Will do. Need to get one first!

Right, I've had a good play about with the potentiometers and I've concluded that this mod is ok and does the job but, in my opinion for games with no background colour like Yar's Revenge, Asteroids etc look better using RF as there's vertical lines accross the black background that the RF seems to "soften" (this is on a 28 inch CRT TV) plus certain things like the colour of the Yar is a nice whitey-bluey colour with RF whilst it's a more harsh blue with composite. The flicker on Asteroids is much more harsh with composite too.

To me it looks like the vertical lines are more due to the limits of the Atari's technology rather than the mod (I could be wrong!).

Don't think I'm gonna bother doing the mod to my six switcher though, particularly as I've just discovered it's a "heavy sixer" and Pal versions seem to be even rarer.

[radfoo]

Yes, the vertical lines are a problem. I think I have fixed that on a new mod I am working on, still needs some work though (also waiting for a new Atari Junior to butcher).

I would not worry about your heavy sixer being rare, I have yet to see a sixer that is not a 'heavy'. I think its a way of ebay sellers to bump the price up

[Sparkfist]

Well there are two type of "Heavy Sixer". There is the Sunnyville model (identified by more square edges), this thing is a collector's item as there are not millions of them out there. Then you have the Taiwan model (idetified because it's much lighter, cheaper plastic and rounded edges), this was made in the thousands maybe more, not rare.

[radfoo]

I own 2 heavy sixers from the USA (I thought it was sunnyvale not sunnyvile?). The only other type I have seen is the 4 switch versions from Ireland. Juniors seem to come from everywhere though, seen Taiwan(or maybe it was Hong Kong or both?), Ireland and Australia.

Perhaps rarity varies between PAL/NTSC?

[Wayne Venomous]

Mine is definatly a "heavy" sixer as it was built in Sunnyvale, California and has the thicker edges. I've compared it with a Taiwan sixer and it's different although not that much difference in weight, certainly wouldn't say it was "heavy" in any sense of the word. Wasn't expensive, bought it for £30 with loads of games.

I'd be really interested in your new mod, let me know when it's ready.

[SgtBowhack]

You can usually soften the video with a capacitor. What you're seeing is likely signal overshoot. If you throw a cap in there between the video and ground, the lines should soften out. Try a variable capacitor (I think something along the lines of 1000-3000pF is good for this, so find one that's in that range if possible).

Basically, the signal shoots from black to a bright color too quickly for the TV to handle, so the TV's color reproduction is funky (ringing/aliasing and other abberations occur). Many game consoles have this problem, and some TVs actually have "game modes" on their AV inputs to soften it internally, because game consoles generally don't bother (too "expensive")

[A.J. Franzman]

I would not worry about your heavy sixer being rare, I have yet to see a sixer that is not a 'heavy'. I think its a way of ebay sellers to bump the price up

You're wrong, there is a difference. The problems are- A: A lot of eBay sellers call their consoles "heavy sixers" just to get higher bids, whether the console is or not, even if they know the difference. And B: The Atari Age 2600 Hardware page calls the heavy sixer the "Sunnyvale Edition" which is inaccurate and highly misleading. Heavy sixers were made in Sunnyvale and Taiwan, and "light sixers" were made in both places too!

The weight difference is less than a pound, not really enough to tell by feel. The extra weight of the "heavy" version comes from extra thick plastic in the case bottom. Internally, both versions are nearly identical.

PAL heavy sixers are quite rare; I would definitely not modify one!

[A.J. Franzman]

Well there are two type of "Heavy Sixer". There is the Sunnyville model (identified by more square edges), this thing is a collector's item as there are not millions of them out there. Then you have the Taiwan model (idetified because it's much lighter, cheaper plastic and rounded edges), this was made in the thousands maybe more, not rare.

Your description sounds backwards. Here's a link to pictures, and description of how to tell them apart adapted from one of my other posts:

Atari 2600 Consoles and Clones
Follow the link above and click the thumbnail images of the first two consoles in the table to see larger versions, and compare them. Note that the "Sunnyvale edition" term used there for the heavy sixer is incorrect and misleading - "heavy sixers" were made in Taiwan too, and some "light sixers" were made in Sunnyvale.

The easiest way for the inexperienced to tell them apart is to look at the black molding at the lower edge of the front woodgrain panel. On the heavy sixer this molding is slightly curved along its entire length, and has a fairly large radius curve at the corners. On the light sixer, the molding is narrower, runs straight across, and is rather sharply angled at the corners.

Also, looking at the ridged top surface of the console, notice on the heavy sixer that the wide molding continues back along both sides. On the light sixer, the side moldings are very thin.

The backs of the consoles where the controllers plug in are not shown but they are very different too.

Also, these consoles were made by the millions, not just thousands! Best estimates are that around 1-2 million heavy sixers were made, and about 20 million Atari VCS and 2600 consoles total of all versions. So by these figures, for about every 10 to 20 light sixer, 4-switch, vader and Junior consoles (together), there was one heavy sixer made. The 4-switch woodgrain model appears to be the most common, but I don't know how many were made. I would guess somewhere between 6 and 10 million.

[Wayne Venomous]

You can usually soften the video with a capacitor. What you're seeing is likely signal overshoot. If you throw a cap in there between the video and ground, the lines should soften out. Try a variable capacitor (I think something along the lines of 1000-3000pF is good for this, so find one that's in that range if possible).

Excellent! Thanks

A friend did mention adding a capacitor but I really didn't have a clue about which bit to connect it to or what size. Will have to see what it looks like on an LCD screen now as CRT TVs are starting to get more difficult to get in the UK.