Ok a couple of questions about modding a Genesis model 1.

[Urzu402]

http://img141.imageshack.us/img141/9950/cimg0260y.jpg

Thats the Mobo it has, Can I do a composite output mod without flipping the board over? Also what solder do I use?

[shadowkn55]

What's so difficult about flipping the board over? If you just want composite, it's much easier and cheaper to buy a set of a/v cables. Now if you want s-video or better, that's a different story.

I still use leaded solder so a 60/40 or 63/37 with rosin core flux will work nicely.

[understatement]

I think he wants to start with something simple if that's the case, your left and right audio will need to be taped from the stereo jacks board and the comp video is pin 2 where the a/v out is on the underside of the board.

[shadowkn55]

Composite video is pin 3. Pin 2 ground. If you are going by the gamesx pinout for the genesis, it's labeled incorrectly. The pin descriptions are correct but the numbers aren't. The neo geo pinout matches the markings on the board.

http://www.gamesx.com/avpinouts/neoav.htm

[Urzu402]

I need to know what chip is what.
Also I need to know if I need any resisters or what not.

[shadowkn55]

If you just want composite video, you can get it from pin 3 of the a/v port. No need for resistors or anything else. Stereo sound can be taken from the pins on the headphone jack.

[Urzu402]

Ok one last question.
Where are grounding points I can use?

[shadowkn55]

Pin 2 on the a/v port is suitable for grounding.

[understatement]

Composite video is pin 3. Pin 2 ground. If you are going by the gamesx pinout for the genesis, it's labeled incorrectly. The pin descriptions are correct but the numbers aren't. The neo geo pinout matches the markings on the board.

http://www.gamesx.com/avpinouts/neoav.htm

:oops: Did not know that I have never modded a model 1 genesis, just did a quick search and that was what I found.

[Urzu402]

Ok I apologize but I have some more questions.

By the headphone jack, which spot is white and which is red?
For the yellow video, what do you mean by the pin 3 of the AV out, the pin on the connector or the one that connects the connector to the motherboard.
Also I'm going to be doing a US/JPN switch and I need to know how much do I need to cut open the cart slot for a nice fit for Mega Drive games