The farthest I got with this setup was a man-in-the-middle setup (as shown below) where I could intercept the CPU's commands to the LCD passing them through the microcontroller and then to the LCD board. I had to move up to a ~11MHz crystal (not shown) on the microcontroller just to come close to allowing the signals to pass through unhindered. The best I managed was a slightly distorted picture...I'll need something faster to actually read the signals so I can reverse engineer them. I've also removed the GameBoy's oscillator so I could clock the GB at a slower speed. This did work but I haven't taken a ton of time to work on the coding side.
The goal when I can work on it again is simply to replace the CPU PBC outright. I will keep the LCD, Voltage Converter and Audio Jack PCBs interfacing them with a newer microcontroller. This would allow all manner of interesting hacks...I could use it as a wireless remote for things, a desktop clock w/ USB, get some emulated or custom games running...endless possibilities. For now I have to put it in a box and try to forget it.
|LCD PCB Front||LCD PCB Back|
|CPU PCB Front||CPU PCB Back|
|Audio Jack Front||Audio Jack Back||Voltage Converter |
|Voltage Converter |