This is a toy NES emulator in Rust, which uses generators for control flow. NOTE: It uses nightly features (check commit history to see working versions of rustc in case something breaks)


Compatibility is very poor! It doesn't support audio output, scrolling, or most NES ROM mappers. Games that use the NROM or UXROM mappers should be loadable, and games that don't use scrolling should be mostly playable.


You'll need to install SDL2 before using Lochnes (see the README for rust-sdl2 for different installation options based on on your platform)

Lochnes can be started with:

$ cargo run --release -- rom.nes

Or, if you want to use a bundled version of SDL2:

$ cargo run --features sdl2/bundled --release -- rom.nes

If 256×240 is too small for you, use --scale to make the window bigger:

$ cargo run --release -- rom.nes --scale=3

If you want debug output, pass -v multiple times (warning: 5 v's makes everything really slow, don't even bother with 6)

$ cargo run --release -- rom.nes -vvvvv


Input bindings is not currently customizable, so here are the current input bindings:

  • Exit: [Esc]
  • A: [Z], (Xbox: A)
  • B: [X], (Xbox: B or X)
  • Start: [Return], (Xbox: Start)
  • Select: [\] (Backslash key), (Xbox: Back)
  • Up/Down/Left/Right: [⇧]/[⇩]/[⇦]/[⇨] (Arrow keys), (Xbox: D-pad)