Progress has been a bit slow but I've finally got some form of video output thanks to Zwenergy's gbaHD project. It's not correctly vertically aligned, which I think might be due to a poor SPS (vsync) connection. I also don't have audio output; it seems hit or miss if your TV is compatible with the audio output format. I'm using a SNES Classic Mini controller as opposed to the original SNES controller and that seems to be working fine. Finally I noticed I'm not getting GameBoy Player features (okay, just rumble really) in games which I have some thoughts on why that's happening, although actually having working rumble is beyond the scope of what I'm planning. I'll be updating the project details slowly with more details on the above developments!