The Zelda Game & Watch Gets a Massive Fan Upgrade
This hacked Zelda Game & Watch was converted into a powerhouse retro emulator that can do what Nintendon’t.
Long before there was a Game Boy, there was the Game & Watch. Released all the way back in 1980, this first handheld game produced by Nintendo was many people’s first experience with gaming on the go. Now that those same gamers have grown up with fond memories of the Game & Watch (and more disposable income), Nintendo has released updated versions of these classic handheld devices.
The new Game & Watch releases are far more capable than the originals, with full-color displays and the ability to play more complex NES titles. However, they still have their limits. Tito from Macho Nacho Productions has a Zelda Game & Watch that can only play a few classic games — yet the hardware inside the device is clearly capable of doing more than that. So, Tito did some hacking to unlock its potential.
The project turns Nintendo’s handheld into a full retro emulation system. Using an ST-Link programmer, Tito first connected directly to the motherboard and dumped the original firmware, preserving the stock software before modifying the device. The biggest challenge was storage: the factory memory chip provides only 16 MB, far too small for a full custom operating system. After carefully removing it with a hot-air station, he installed a 64 MB replacement chip and flashed an open-source firmware called RetroGo.
To actually hold games, the Game & Watch needed expandable storage, which meant adding a microSD card reader. The solution required extremely precise microsoldering — attaching a custom ribbon cable directly to tiny CPU pins and adding supporting components such as capacitors, a resistor, and a voltage regulator. To make the card accessible, a precisely drilled slot was cut into the plastic shell using community-designed 3D-printed guides.
Once completed, the device gained many new features. It still boots into the original Nintendo interface, but a special button combination launches the custom environment. From there, the handheld can run games from systems like the NES, SNES, Game Boy, Game Boy Color, Sega Genesis, and TurboGrafx-16. RetroGo adds modern conveniences too, including save states, customizable display scaling, adjustable brightness and volume, turbo buttons, and even optional CPU overclocking.
There is nothing easy about this mod, so unless you are very experienced with a soldering iron you probably don’t want to try this one at home. In any case, it’s a fantastic hack and the video is well worth a watch.