The Game Boy has remained popular among console modders and hackers for many reasons. First, its simple Z80-based processor is easy to work with. The entire instruction set can be memorized by a single person (try that with the x86-64 instruction set!) so it’s easy to write programs and decompile existing ROMs. Getting modified or homebrew software onto a Game Boy can be difficult, and so many just use emulators which may or may not perfectly emulate the real hardware. This RP2040-based Game Boy Cartridge is an awesome way to interact with the hardware of the Game Boy!
It’s easy to load ROM files using a web app called WebUSB. And with 16MB of QSPI flash, it can hold a few different ROM images. The only limitation is the speed at which the RP2040 provides data to the Game Boy — it’s fast enough for all original Game Boy games, but the Game Boy Color used a double data rate that this version can’t keep up with (though I suspect the RP2040 firmware could be modified to speed things up?) and so most Game Boy Color games won’t work.
Of course, we have to remind you not to use items like this for anything illegal. However, if you’re purchasing something like this, you’re probably either developing your own games, or you’re more than capable of reading the ROMs from cartridges you own! What I’m looking forward to is seeing what else this cartridge can do — the RP2040 has a lot of horsepower compared to the Z80, and with different firmware, you could probably do some pretty creative and wild things.
One last note from the seller — this cartridge naturally draws more current than a standard cartridge, as most cartridges just have a ROM chip and maybe some decoding logic rather than a dual-core ARM Cortex-M0+ running at 133MHz… so consider this when using it in conjunction with other Game Boy mods. You might need to beef up your power supply or mod your Game Boy with lithium-ion batteries or something!