Squareboi is an open hardware cartridge system for the Game Boy Color, made to be as accessible and DIY-friendly as possible. Using a handful of off-the-shelf components, it provides the same functionality as an original cartridge, compatible with the majority of programs. Additionally, an Arduino-based programmer allows for easy transfer of games and save data.
Up to 4MB ROM/32KB RAM storage space
Stores save data without needing a battery
Made of common, off-the-shelf parts
Fully compatible with MBC1 and MBC5 mappers, partial support for MBC2 and MBC3
Programmer works as a general purpose cartridge reader
Easy to build: A basic version can be made with entirely through-hole components
Powered by a single 5V rail
Compatible with third-party programmers, like the widespread GBxCart RW
A thorough explanation of how the system works, and how to assemble it, can be found in the manual file, HERE.
Squareboi's existence is only possible due to the continued efforts of multiple individuals dedicated to reverse engineering and documenting the Game Boy hardware. A full list of those whose work I've built upon can be found within the manual.
Still, I'd like to say it again: Thanks to all of you! I wouldn't have gotten here alone.
Squareboi featured on Hackaday
Squareboi is the work of a hobbyist – And while significant care was taken to make it reliable, I cannot guarantee that it will work in your specific use case, or that it will be compatible with your hardware.
Squareboi is licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0). https://creativecommons.org/licenses/by/4.0/#deed-conditions
In essence, if you share or adapt this work, you must credit the author (ALXCO), and provide a link to the Squareboi repository, at: https://github.com/ALXCO-Hardware/squareboi