He managed to intercept and reconstruct Game Boy gameplay from its memory bus

If you thought you knew everything about the Game Boy, Nintendo’s portable console released in 1989, well, think again! A passionate developer has achieved an impressive and unexpected feat: Reconstructing Game Boy gameplay simply by “observing” the data flowing on its memory bus. This technical achievement, which dates back to last year (yes, I’m a bit late ^^), opens up fascinating new perspectives for the preservation of this cult console.

But how on earth is this possible?

The answer lies in two words: reverse engineering and a lot of perseverance. Our tinkering genius designed a small adapter that plugs between the console and the game cartridge, capable of spying in real-time on all the information exchanged on the Game Boy’s memory bus.

By meticulously analyzing this seemingly incomprehensible data stream, our genius tinkerer managed to reconstruct the state of the console’s memory at every moment. Then, he “simply” had to emulate the Game Boy’s graphics processor to recreate the image displayed on the screen. The result is astounding: you can play the game as if nothing had happened!

Of course, in practice, it’s obviously a bit more complicated than that. It required handling numerous specific cases related to the Game Boy’s internal functioning: decoding processor instructions, synchronizing everything, dealing with the console’s famous bugs… A true masterwork.

The adapter, named “GB Interceptor,” connects via USB and behaves like a webcam, allowing the game to be recorded or streamed without any specific drivers. The capture is done at 640×576 at 60 frames per second, all within a casing barely larger than a cartridge. In short, it’s beautiful, and it works!

You can now capture game sessions on original hardware with ease, delighting speedrun enthusiasts and other retro challenges.

Of course, the method has its limits: no audio, some graphical glitches here and there, and incompatibility with certain exotic games, but there’s no doubt that the technique will be refined and extended to other retro platforms.

And to conclude, I’ll leave you with this magnificent video that has nothing to do with this interception technique except that it deals with Game Boy hardware. I found it very cool!