GB Operator and SN Operator: Real Nintendo Cartridges via USB-C

A 26-year-old copy of Pokémon Pinball recently lost its save file — the Charmander caught for a daughter, the high scores set together, all gone. It is an increasingly common fate for original Nintendo cartridges, whose tiny watch batteries were never designed to last this long. The GB Operator, a $50 USB-C cartridge reader made by Romanian company Epilogue, had backed up that save months earlier, which is precisely the point.

Epilogue makes two devices currently available to consumers. The GB Operator is a transparent trapezoidal reader that connects Game Boy, Game Boy Color, and Game Boy Advance cartridges to Windows PCs, MacBooks, and devices such as the Steam Deck via USB-C. The SN Operator, priced at $60, performs the same function for Super Nintendo and Japanese Super Famicom titles. A Nintendo 64 version is also in development, according to the company.

How the hardware works

Neither device contains original Nintendo chips nor field-programmable gate arrays. When a cartridge is inserted and play is initiated through Epilogue's Playback software, the ROM is saved to the host computer and run inside an emulator. The software is designed to make that process nearly invisible: plug in the reader, insert the cart, press play, and the game appears on screen. When a player saves within the game, Epilogue's software is designed to write that save automatically back to the physical cartridge. Removing the cart causes the game to close immediately.

That bidirectional save functionality is one of the more practically useful features. A user can begin a session on a PC, move the cartridge to a Steam Deck, and then slot it into an original Game Boy or Super Nintendo and continue from the same save point on original hardware. For users who do not need automatic save-writing, an alternative emulator core offers RetroAchievements support, save states, and the ability to rewind gameplay.

The SN Operator's clockspeed is factory-calibrated using satellites on every unit, which Epilogue says allows it to dump certain SNES games without errors. The company also built a CRT filter into the Playback software — co-founder Petru Sebastian Toader told The Verge he wrote that filter himself — and online multiplayer support is described as a work in progress. Epilogue contributes both money and code to open-source emulators, and has partnered with the developers of the Delta Emulator so that real cartridges can be used directly with a phone. The company's own Flashback app allows a Game Boy Camera cartridge to function as a camera on a smartphone.

There is also a peripheral emulation feature in the SN Operator. Games that originally required the Super Scope light gun or the SNES Mouse — titles such as Metal Combat: Falcon's Revenge and Mario Paint — can be played using a standard PC mouse cursor or a controller's gyroscope, mapped to those inputs in software.

Limitations the company does not prominently advertise

The Operators do not work with multi-game flashcarts and are incompatible with the Super Game Boy adapter. Cartridge detection is reportedly less forgiving than original hardware: carts in less-than-perfect condition, including some Japanese releases, can drop connection mid-session if nudged. The counterfeit cartridge detection feature, which Epilogue markets prominently, was described by The Verge as unreliable in testing. The Game Boy Camera webcam function, also advertised by the company, operates as an OBS screen-recording workaround rather than a native webcam input.

There is a broader urgency to the product's appeal. Watch batteries in second-generation Pokémon cartridges — Gold, Silver, and Crystal — power real-time clocks in addition to save memory, and those batteries are reported to have drained within a decade for many carts, making save recovery likely impossible. Even first-generation Game Boy cartridges are approaching end-of-battery life, with saves on decades-old copies of titles such as The Legend of Zelda: Link's Awakening disappearing in recent months.

While open-source alternatives such as the Open Source Cartridge Reader exist alongside a range of Game Boy readers, The Verge assessed Epilogue's hardware as offering high build quality relative to its price, with circuit boards visible through polycarbonate casings. The hardware is described as proprietary, but the company's broader contribution to the open-source emulation ecosystem distinguishes it from purely commercial cartridge-reader products.

Related coverage: Nepal Flood Death Toll Rises to 1,127 with Nearly 4,900 Missing One Week On.