Our goal is to make a MBC5 cart with 32Mbit ROM and 32Kbit RAM + Batt, that is compatible with almost all GB/GBC commercial games. MBC5 is backwards compatible with MBC1 and MBC2, so all software based in this two mappers will work aswell. The first one I built, in order to test the programmer, was a MBC1 cart with 4Mbit ROM + 8K SRAM + Batt. Pic:
Next I have built a 32Mbit Cart, the same procedure as the 4Mbit one. The best chip suited for this modification is an AM29F032 Flash in SO44 package, easiest to adapt and solder.
It works very nice. The cart is built from a Zelda DX, so we have a MBC5 cart with 32Mbit Flash and 32Kbit SRAM + Batt.
After this cart, I have made a design for a flash cart to send it to a pcb manufacturig service:
The first PCB's have arrived! We're testing it:
Take a look at: Cart's architecture