NES Emulator

A Nintendo Entertainment System (NES) emulator built in Rust.

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Showcase

Note

This project was created purely as a hobby, a personal challenge, and an opportunity to practice low-level programming and system architecture in Rust. So for the foreseeable future it is not intended to compete with established emulators but rather serves as a proof of concept and a deep learning experience regarding low-level programming and the NES hardware.

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How to Run

Make sure you have Rust and Cargo installed on your system.

# Clone the repository
git clone https://github.com/Polar-404/NES_Emulator.git

# Navigate to the directory
cd NES_Emulator

# Compile and run
cargo run --release

Controls

NES Button	Primary	Secondary
D-Pad Up	W	Up Arrow
D-Pad Down	S	Down Arrow
D-Pad Left	A	Left Arrow
D-Pad Right	D	Right Arrow
A	J	Z
B	K	X
Select	N	C
Start	M	V

System Commands:

• Volume Up: +
• Volume Down: -
• Pause/Menu: Esc
• Change Color Palette: . (Period)
• Paste ROM Path: Ctrl + V

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Current Features

• Ricoh 2A03 (6502) CPU (including indirect JMP bug support).

• PPU (Picture Processing Unit).

• Partial APU (Audio Processing Unit).

• Controller input implemented.

• Supported mappers:

  • NROM (Mapper 0)

  • MMC1 (Mapper 1)

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Tech Stack

• Rust: Main language used for the project.

• Macroquad: Core library for graphics rendering and input handling.

• Cpal: Library for audio processing and output.

• Ringbuf: Lock-free circular buffer for audio.

• Arboard: System clipboard access.

• Others: image, lazy_static, sysinfo.

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Roadmap / To-Do

As this is an ongoing learning project, several areas still need improvement:

• User Interface: Improve the start menu and add more graphics and audio configuration options.

• Audio (APU): Implement the DMC (Delta Modulation Channel).

• Synchronization: Sync audio with FPS to maintain a more stable frame rate, faithful to the original console.

• Mappers: Add support for more mappers (e.g., MMC3) to increase game compatibility.

• Saves: Implement Save/Load states functionality.

• Code Quality: Refactor and clean up the codebase, and potentially add documentation and internationalization (EN/PT-BR).

• Accuracy & Testing: Fix known bugs (e.g., failing test 3 in official_only.nes) and run/create more accuracy tests.

• Unofficial Opcodes: Implement undocumented 6502 instructions.

• Scripting: Implement user script support with Lua.

• More Palettes: Implement the ability for the user to insert their own palettes via interface and/or a designated folder with .pal files (maybe even .hex files).

• Custom Graphics Pipeline: Transition from Macroquad to OpenGL/Glow for

  • lower input latency
  • better frame synchronization.
  • Custom CRT/NTSC shaders.

• WebAssembly (WASM): Browser-based emulation — play directly without installing anything.

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Acknowledgments & References

This project would not have been possible without the incredible emulation community and the educational resources available online. Special thanks to:

• Nesdev: The Nesdev wiki and community are the absolute standard for NES development. Practically all technical knowledge here came from them.

• javidx9 (OneLoneCoder): His excellent video series on creating an NES emulator was the starting point and main architectural inspiration.

• bugzmanov/nes_ebook: The e-book "Writing NES Emulator in Rust" was a fundamental reference. Parts of the CPU implementation and Design Patterns were heavily based on his code to understand Rust's nuances applied to emulation.

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Licenses

Distributed under the MIT License. Feel free to study, modify, and use this code in your own experiments.