slot Turns Anbernic's RG SP Into a Deliberately Single-System Game Boy Advance Handheld

Brandon Kowalski creates slot for Anbernic's RG SP clamshell, transforming the multi-system emulation handheld into a focused, cartridge-style Game Boy Advance experience.

The retro-handheld scene has spent years celebrating devices that can emulate as many systems as possible. A new project called slot takes exactly the opposite approach. Created by Brandon Kowalski for Anbernic's RG SP, slot is a custom frontend dedicated specifically to Game Boy Advance software. Rather than presenting dozens of emulator folders and thousands of ROMs, the interface treats each game like a physical cartridge inside a virtual collection. Players move through a carousel with the shoulder buttons, select a cartridge and begin playing. A tap of the A button resumes the latest save state, while holding A starts the game cleanly. Holding Menu ejects the virtual cartridge, automatically saves the current state and returns to the collection. The RG SP's clamshell design is integrated into the experience as well. Closing the lid saves the game and turns off the display; opening it resumes play, while leaving the system closed for several minutes powers the handheld down so it can resume from the automatically created state on its next boot. Fast-forward and rewind are mapped to the triggers, and users can maintain multiple save states through a dedicated switcher. Perhaps most interestingly, link play between two RG SP units is supported when using gpSP, allowing a pair of these modern handhelds to recreate part of the multiplayer experience associated with original Game Boy Advance hardware. Users can choose between mGBA and gpSP depending on their needs. The project runs on an AGS-102-derived minimal operating environment built from BaseOS rather than Anbernic's ordinary stock interface. That supporting OS retains useful hardware features such as Wi-Fi, Bluetooth and graphics acceleration while trimming the background environment and boot process. Kowalski is also unusually transparent about AI use: the Rust frontend and some SVG material were generated with Claude Opus and then manually reviewed. The real conceptual value of slot is not technical extravagance but focus. Choice overload has become a strange side effect of modern emulation handhelds. A device capable of running twenty consoles can contain tens of thousands of games, leaving users browsing menus longer than they actually play. slot deliberately recreates the smaller mental model of owning a handful of GBA cartridges. The RG SP can run much more software than this, but the project asks whether deliberately pretending it cannot might actually make the handheld more enjoyable.