#nes #emulator #toy #flow #generators #control

nightly bin+lib lochnes

A toy NES emulator in Rust

2 releases

Uses new Rust 2021

0.1.1 Jul 2, 2022
0.1.0 Oct 20, 2019

MIT license

6MB
5K SLoC

Lochnes

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This is a toy NES emulator in Rust, which uses generators for control flow. I wrote a blog post going over some of the implementation details here: https://kyle.space/posts/i-made-a-nes-emulator/

NOTE: Lochnes uses nightly features! The project is pinned to a specific working nightly version of Rust in rust-toolchain.toml. Rustup should ensure that an appropriate version of Rust is installed when building or running the project from the repo root.

Compatibility

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.

Usage

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 256Γ—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

Controls

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)

License

Licensed under the MIT license

Dependencies

~17MB
~364K SLoC