s&Famicom

A NES emulator running inside s&box. Running it Press Play. You land on the ROM browser, which lists every `.nes` file it finds and lets you pick one. Filenames don't matter - whatever is in the folder shows up. Leaving a game with Tab parks it rather than shutting it down - the whole console state (RAM, PPU, mapper banks) is kept, and the game shows a RESUME tag in the list. Picking it again drops you back exactly where you were, so you can switch between several games freely. Parked sessions live in memory only; they don't survive closing the game. Adding ROMs Drop `.nes` files into the game's data folder, roughly: ``` <steam>/steamapps/common/sbox/data/rosner/s_famicom/roms/ ``` Press Tab in the browser to rescan without restarting. The emulator logs every ROM it finds on each scan, so if something isn't showing up the console will say what it did see. ROMs are not included - supply your own. Controls D-Pad -> WASD/Arrow keys A button -> X key B button -> Z key Start button -> Enter key Select button -> Backspace key Pause emulation -> P key Reset console -> F5 key Back to the game list -> Tab key In the browser: up/down to move, Enter or X to play, Tab to rescan. The mouse works too. Known limitations - Undocumented 6502 opcodes (LAX, SAX, DCP, ISB, SLO, RLA, SRE, RRA) execute as no-ops. Most commercial games never touch them, but a few do. - No battery-save persistence. MMC1/MMC3 carts get their 8K of work RAM, but it isn't written to disk between sessions. - NTSC only - no PAL timing. - No colour emphasis (the top three bits of `$2001`). Rarely used, and mostly for full-screen tints. - No save states. Credits - nes-sharp - the C# NES core this was ported from. - psxemu - the reference for how to host an emulator inside s&box: texture upload path, `SoundStream` handling and frame pacing. - NESdev Wiki - hardware documentation, particularly for the APU channels and mixer, which were written from scratch here.