3dSen - RetroBIOS¶
Technical notes
Closed-source Unity/C# NES emulator by Geod Studio, sold on Steam and itch.io for Windows, macOS and Linux. Rebuilds NES cartridge games as voxel scenes at runtime. Emulation is compiled into the binary and the NES has no boot ROM, so no external BIOS or firmware is loaded. Cartridge games only, no Famicom Disk System and therefore no disksys.rom: ES-DE lists it under nes and famicom but not fds, and RetroBat maps it to nes3d alone and documents "No specific BIOS is required to play NES games".
Games are registered through the emulator UI, which writes rom.json in the Unity persistent data path (Windows AppData\LocalLow\Geod Studio\3dSen\, Linux ~/.config/unity3d/Geod Studio/3dSen/, macOS ~/Library/Logs/Geod Studio/3dSen/) binding a fixed numeric ID to the user ROM. Launching passes that ID rather than a path: 3dSen.exe -id=N.
Per-game 3D profiles are .3dn files, protobuf-serialized behind a "3dn" title header and a version field (3DNesManager Classes/3DNTools.cs:14-31, 51-58), loaded when a game starts (3DNes_Engine Engine3D.cs:37, Load3DN). The 100 official profiles ship inside the application. Profiles built with 3dSenMaker are optional per-game additions installed from the UI since v0.9, and cover art packs are optional files placed in CoverArt/ under the same data path. ROMs are user-supplied, the emulator ships with no game content.
No BIOS or firmware files required. Generated on 2026-08-23T16:12:05Z