Odyssey 2 controller mod....

[CRTGAMER]

http://pinouts.ru/Game/genesiscontroller_pinout.shtml

I don't think you'll be able to get the Genesis to work. There's a typo in the diagram; it repeats Up Down instead of having them be Left Right (not sure which maps to which). And overall the way it works is that the Genesis understands the status of the Select pin to determine what buttons are being pressed. The Odyssey2/Atari don't understand that interface.

I heard mixed info that Genesis controller would work or not.

You could get it to work, but it wouldn't be as simple as rewiring a port. You'd have to include a chip to handle the way the select pin works on the Genny controller.

Not worried about the select, would the Genesis controller direction and one fire button work 2600 mode without that chip?

[wclem]

I have the hard wired controller version. Inside though there is a connector to some funky board. I am gonna just unplug it to preserve the controller and wire in that 9 pin as suggested.

[MrPopo]

Not worried about the select, would the Genesis controller direction and one fire button work 2600 mode without that chip?

Now that I think about it the Genny controller works on an SMS. I believe converting an SMS controller to a 2600 controller is just a matter of rewiring a few pins on the connector. You'll have to search up documentation on that.