NES RetroAchievements Adapter Brings Modern Achievements to Classic Games Like Metroid

While you rarely come across M6 demo kiosks out in the wild, the NES RetroAchievements Adapter by Fábio Toledo (odelot) aims to eventually add achievement tracking to all classic games, similar to modern gaming systems. Simply put, the device sits between the NES console and the game cartridge, monitoring memory writes to detect when specific in-game achievements are unlocked (like reaching a score or completing a level).

Unlike a Game Genie, which modifies game values, this adapter observes them passively to track progress. It adds internet capability to the NES via an ESP32 module, allowing it to communicate with the RetroAchievements platform in real-time to log achievements. The design also incorporates a Raspberry Pi Pico for interfacing with the NES, an LCD screen to display achievement notifications, and a buzzer for audio feedback. The goal is to miniaturize it to the size of a Game Genie cartridge in future phases. Interested? You can check out the Github page here.

Most importantly, all documentation, schematics, and code are shared so enthusiasts can build their own adapters (using breadboards or PCBs), suggest improvements, or adapt it for other consoles. A preliminary version already detects hardcoded achievements, validating the concept, though full RetroAchievements integration is still in progress.

The prototypes do not use logic level conversion to avoid signal delays. The bus between the cartridge and the NES is disabled when identifying the cartridge (not affecting the NES), and current levels are within Pico’s limits. In the final version, current limiting will be considered to reduce stress on the Pico. If someone in the community identifies the need for level shifting and develops a test scheme without compromising signals, contributions are welcome,” said its creator.

[Source]