Even though it’s over 30 years old now, the Game Boy platform still has adherents who enter online tournaments. No, the Game Boy itself is not an online device, but players would still like to show off their skills. One way would be to set up a video camera aimed at the gaming device, but then you have to consider, lighting, comfort, staying still, etc.

The Problem Statement

So, Tetris enthusiasts have run into a unique problem: while maintaining their muscle memory and playing competitively, they must use their Game Boys for tournaments. There has previously been no way to stream footage from unmodified Game Boys. Enter the GB Interceptor, a device developed by Sebastian Staacks to solve this problem!

The Solution 

GB Interceptor for Game Boy
The GB Interceptor. Source: Sebastian Staacks
The GB Interceptor is an absolutely ingenious middle-man adapter that connects directly to the cartridge slot of an unsuspecting Game Boy, and then allows you to plug in the equally unsuspecting game cartridge. This allows the Interceptor to intercept a copy of the transferred data without modifying the game itself. To interpret and display this data in a usable format, the device uses an RP2040 microcontroller and emulator firmware to recreate a copy of the Game Boy's Video RAM (VRAM). This involves emulating the Game Boy's CPU and graphics unit (PPU) on the RP2040, a process that requires the microcontroller to be overclocked to 225 MHz.
 
GB Interceptor internals of the board that connects between Game Boy and cartridge.
Inside the GB Interceptor. Source: Sebastian Staacks
Check out Sebastian’s original article here, which links out to his GitHub and all the other resources you need, as he does not sell the fully assembled wizardry himself.

I imagine that, in addition to allowing for the streaming of gameplay footage from unmodified Game Boys, the GB Interceptor also has the potential to serve as a debugging tool for Game Boy software developers. The device could be connected to a laptop, allowing users to examine the data transferred between the Game Boy and cartridge in real-time.

The GB Interceptor offers a unique solution for Tetris (or any other classical Game Boy games, so no color) enthusiasts looking to stream their gameplay footage from their personal Game Boys.
 
The GB Interceptor in action.
GB Interceptor in action. Source: Sebastian Staacks