Of course. I think it'd be great to have two full SGB emulators, in case certain games only work in one or the other. Plus I could use help with the multi-player support. I'm not entirely sure how you increment to choose the next gamepad. The pandocs method breaks games and seems to increment way too much.

All you really need for my work is supergameboy/interface. The stuff under bsnes/src/chip/supergameboy is just the DLL passthru and my $7800 access trick.

The fun part will be using MESS' GB support instead of Gambatte (which is GPLv2.) You'll need to be able to read out the LY counter, hook DMG $ff00 accesses, and make sure all video up to the current scanline is rendered when reading from $7800.

If you take the easy way like I did, you'll need to feed the S-CPU $2180 access address to the SGB core. And if you take the hard way, please do share if you can figure it out, heh.

Feel free to ask any questions and I'll do my best to explain.