A hardware creator has developed a compact Game Boy emulator utilizing an e-paper display with an "actually playable" refresh rate, demonstrated through a playthrough of Pokémon Blue. This project challenges the common perception that e-paper displays, known for their slow refresh rates and ghosting, are unsuitable for gaming.
Wenting Zhang, the creator behind the device, previously spent four years developing an open-source e-ink monitor capable of a 60 fps refresh rate. This earlier work involved using significantly more memory than typical e-paper displays and employing greyscaling and dithering techniques to achieve smoother visuals. Zhang then leveraged this experience for the smaller emulation device.
The pocket-sized emulator is built using an ESP32 SoC and a M5Stack PaperS3 ereader. The custom high refresh rate driver makes it well-suited for games like Pokémon Blue and The Legend of Zelda: Link's Awakening. Emulation for Game Boy Color titles remains a work in progress due to hardware and emulator software limitations.
Creative solutions were also applied to address the M5Stack PaperS3's limited speaker. Zhang implemented audio engineering techniques to filter iconic Nintendo soundtracks into a single, crunchy tone, giving the audio a distinct character. While the initial result is detailed but underpowered and quiet, the approach adds a unique flavor to the retro experience.
The e-Ink emulator performs best with slower-paced, visually simpler games. For more action-oriented classics like Tetris, an input device separate from the M5Stack PaperS3's touchscreen is beneficial, although Bluetooth integration is currently not ideal. Zhang is also exploring the potential of the open-source repository to adapt the "Paperboy" device for visual novels.