Some time ago I was playing and learning to use eagle and designed this board. The intent was to create something to dump roms and read/write saves of Gameboy cartridges. At the time I still had not the Gameboy camera, but I have plans about interfacing it.
I wanted to make everything from zero, and with what I had. If you want something professional, I recommend you to have a look at Reiner Ziegler’s page. There you can find schematic/board files of the his board, as well a software for use with it.
Returning to my board. The main component in the board is the microcontroller, the AVR Atmega32. This board does not have a serial-USB converter, so a external adapter must be used. To connect the cartridge, a game boy color cartridge slot is used.
Game paks, the cartridges, have in their connector pins for address, data and control. As the address bus only allow 32k ROMs to be accessed, bank switching is necessary for most cartridges(Some cartridges can have up to 8MB ROM). Basically, each cartridge can have different sizes of ROM and RAM, and memory bank controllers, which makes reading every cartridge as a special case.
I still don’t have anything coded for it, but I am working on it, hehe. As I have not tested, the board is not guaranteed to work.
If interested, you can download the EAGLE files here.