Well I got some extra cash today so I decided to go back into this project hard. I originally wanted to just dive strait into a small PCB to fit in a Gameboy cartridge but there is so little room to work with. I have decided to continue to use my Terasic DE1 board with the Altera Cyclone II on it. I will still use a Actel ProASIC3 nano in my final design though.

So what do I need to do know? I am going to design a custom board that will plug into the DE1 boards two 40 pin sockets. I will fit the board with a Atmel ATXMEGA32A4 to handle SD Card access and file transfer. A Everspin MR0A08BYS35 1MBit MRAM will be added to act as nonvolatile storage for the games SRAM until next bootup were it will be backed up to the SD Card, It will also hold the bootloader. A Cypress CY62167EV30LL 16Mbit SRAM will be added to hold the games ROM data. Some buffer chips will be added to drop the 5v logic from the Gameboy to 3.3v for the FPGA also. Going to try and design the board using gEDA.

Not sure if I will need the MCU right now but going to add it into the design anyway for now. I am going to try and see if I can get the Gameboy to access the SD Card and handle the FAT filesystem in software on the Gameboy. Not sure how fast the file transfers will be but it would save board room on the final design and also cut down on cost. Worst comes to worst I will have to do a 4 layer board and only make a few.