New Gen3 RGB Mod->Not needed *mt*

[shiett]

Hello,

    I was just reading the new Genesis 3 S-Video and RGB modification page and thought it was odd that there is an RGB modification as I have two Genesis 3's that happily output RGB without any modification.
I have one that looks like the picture in the tuturial and another version that has the main chip in a baseball diamond shape placement.  I have used both on my Atari SC1224 monitor with the lm1881/220uf cap combination without problem.  I connect it with a cable I made from a connector from a RF adapter so I can use the original 9 pin connector on the console (also works with the Genesis 2).  

Would the author of the tutorial please verify fom the multi-out connector that the RGB line are not connected to the RGB lines on their version of the Genesis 3 as this modification is not needed in all cases of the Genesis 3.  I can take some picture of the mainboards of the two I have if this will help identify different revisions.

Please note that the RGB lines on the one I have similar to the revision pictured in the tutorial  are not connected to the Mult-Out via the CXA1645M RGB output, but from the original source of the RGB signals.  The outputs from pins 21,22, and 23 are just the passthough signals from the input RGB signals from pins 2,3 and 4.    For some odd reason the other revision I own does have pin 23 running somewhere, but not 21 or 22 (doesn't affect the RGB though).

If anymore information is need please let me know.

Shiett

[NFG]

That's an interesting thing...  I was told the system didn't output RGB but I never tested it to be sure.  I looked at the chip and there were no pins coming off the 1645, so I just used that as confirmation.  I'll have a look at mine and verify the situation.

[matt]

Yes, I've run several Gen3s in RGB, and they all work fine.

I have found, though, that the video quality isn't the best - they have the same "vertical line problem" as some Neo-Geos.  Probably something can be done about this.

Some other stuff about the Gen3:

With the S-Video mod, I've found that you get a nicer picture if you don't add a 75ohm resistor to the Chroma line.

As far as sound goes, all the Gen3s I've tested don't have stereo.  The mono and left audio pins are connected together, and the right audio pin is empty.  There's only one sound driver chip, so even if stereo is possible somehow, it'd be so much work that it wouldn't be worth it.  To make things a little nicer, you can solder together the right and left audio pins on the motherboard, and at least you'll get sound from both speakers that way.  This is really easy to do, since they're right next to each other.

It appears that there are at least two different Gen3 motherboard revisions, with totally different region jumper placements.  The other model (not shown on the Genesis mod page) has the main IC placed diagonally, and the jumpers are up near the cart port (easy to spot if you look).

[shiett]

Hi Matt,

  Would you elaborate on the "vertical line" problem as I do not see this on my Gen3's with the Atari SC1224 monitor I am using.  I compared the output from a Gen 1,2 and 3 and all look the same without any interference. Do you have a picture that show the problem as this is curious?

Thanks,

Shiett

[matt]

I believe Lawrence has a page up showing comparisons between the various Neo-Geo models.  The effect on the Gen3 is basically the same.

Mind you, your mileage may vary depending on the console.

[Arakon]

I can confirm that the genesis 3 outputs RGB just fine.