[Jose Torres] sent in his latest attempt at creating a custom Gameboy game cartridge. We’ve featured his projects before, and he’s come a lot closer over the last 2 years. He’s aiming to create an easy interface for homebrewers that doesn’t require any other special equipment. In this revision, he’s using a PIC and a memory controller to interface between an SD card and the Gameboy. The cart also has USB support for uploading files to the SD card and reprogramming the PIC. Because it’s just USB mass storage, it will work on almost any modern OS. He’s currently testing the device, but hopes to be selling them soon for $40.