An open-source, cheap, non-reprogrammable GameBoy cartridge design. I figure most people who use the GameBoy as a music medium only use one or two different applications, so it makes more sense to own one or two $25 non-reprogrammable cartridges with the necessary apps loaded rather than a $60 reprogrammable cartridge which the user might only program once. It's actually a project I'm thinking about doing myself.
I just want nanoloop to not be 80. And also have the ease of saving/backing up/transferring nanoloop data as easy as LSDJ is.