A modder's customized watch runs Game Boy Color games using its original hardware

Chris Hackmann, who goes by LeggoMyFroggo, has managed to cram a fully functional Game Boy Color into a 38 mm wristwatch, which he proudly calls the Time Frog Color. The Game Boy Color watch uses actual GBC hardware rather than emulation and can run tiny physical game cartridges. It’s a less-than-optimal way to play GBC games, but the idea baffles and intrigues modders and gamers alike.

Right from the get-go, Hackmann set three very strict rules. The watch had to use the original Game Boy Color CPU, support physical cartridges, and still tell the time when it was turned off. So his go-to solution was a classic Sharp SM83 processor paired with its video RAM and a 1.12-inch color display.

Since the tiny LCD screen isn’t compatible with the GBC chip, he had to use a Raspberry Pi RP2040 microcontroller for signal translation. While the tiny coprocessor can run circles around the GBC’s own CPU, its size and thermal profile also help everything fit perfectly inside the 38 mm aluminum case, which looks right at home alongside the latest smartwatches.

However, the project wasn’t without its fair share of headaches. Given the restrictions he imposed on himself, Hackmann refused to use an SD card containing legally dumped ROM files. Instead, he decided to create mini GBC cartridges that would slide into an M.2 slot. As for the battery, Hackmann somehow managed to encase it in the watch's silicone wristband and connect it via a flexible circuit, which sounds quite dangerous in practice. 

The Time Frog Color or Game Boy Color watch is controlled via tiny tactile switches housed under 3D-printed caps. The case, adorned in metallic Nintendo purple, is CNC-machined from aluminum. For proof, he ran a tiny cartridge of Pokémon Gold on the GBC wristwatch, and it ran perfectly.

A technically sound, if slightly impractical, proof-of-concept smartwatch

However, the trade-offs are pretty obvious. Despite being a fully functional GBC on your wrist, the screen is too small to clearly see on-screen visuals, the control scheme is clunky, the battery life is shorter than a regular GBC's, and, to top it all off, there’s no audio. 

Despite all these setbacks, it’s a pretty awesome proof of concept, capable of running Game Boy titles on your wrist and still telling the time when you’re not playing anything, provided your battery doesn’t run out.

To close out the video, Hackmann said, “If this all sounds needlessly complicated, have you even thought about this? It’s a Game Boy Color with a less-than-optimal experience, shorter battery life than most, and a right to exist just ahead of macaroni and cheese with ketchup. But in the end, I’m still shocked that I have a real, playable Game Boy Color, in at least a technical sense, on my wrist.”

With renewed Game Boy Color consoles already fetching north of $100 on Amazon, this might a somewhat expensive hobby to tinker with but one that is sure to pique some interest thanks to the unique approach taken by the modder, especially when it comes to its own 'cartridges'.