Here's a similar thread:

http://chipmusic.org/forums/topic/9505/ … ge-to-dmg/

and kitsch was working on a converter board at one point:

http://chipmusic.org/forums/post/155783/#p155783

Hi all. I'm new here, and am looking for some mod help. While I'm not a chiptune creator, I am a DJ and a retro game collector who's been recently bitten by the modding bug and I know that chiptune dudes are the best GameBoy modders around, so I figured I'd try and harvest your knowledge...

I came up with the wacky idea to cram a DMG into an NES Advantage controller. I don't have a mockup image of the design yet (it's just scetched onto a notebook) but essentially, The top half of a DMG (including screen and both boards) will stick up out of the top of the Advantage case's top left corner, add an internal rechargable battery, relocate speaker and headphone jack toward bottom of the controller, and preferably backlight the screen.

The biggest problem I'm running into is trying to figure out the controls. I know I could just solder contacts from the NES Advantage board to the DMG board, but I would like to keep all of the functionality of the Advantage (mainly turbo... slow is stupid) so I was wondering how I would connect the actual NES controller cable to the DMG board (inside the case of course)... But how would I go about making the connections? Is there some kind of oscillator IC chip that I need to convert the signal?

And a lesser question, what are my options on power? I want it to be internal and rechargable... Just looking to draw from the experience of others.

Thanks for taking the time to read all this!