RustyGB 🦀

RustyGB is a high-performance, cycle-accurate Game Boy (DMG) emulator written entirely in Rust from scratch.

This project is a clean-room implementation created solely for educational purposes to study hardware architecture and emulation development.

⚠️ IMPORTANT: This emulator does not contain any Nintendo proprietary code, BIOS, firmware, or copyrighted assets. It mimics the hardware behavior through original code written in Rust.

⚖️ Legal Disclaimer & Anti-Piracy Policy

Please read carefully before using:

1. No Nintendo Code: No code from the original Game Boy BIOS or official Nintendo software has been used, reverse-engineered from leaked sources, or included in this repository. All logic is based on public hardware documentation and independent research.
2. No ROMs Provided: This repository does not and will never provide, distribute, or link to commercial ROM files (game images).
3. Use Legally Owned Games: Users are expected to dump their own cartridges from games they legally possess. We do not condone piracy.
4. Trademarks: "Game Boy", "Pokemon", "Tetris", and "Zelda" are trademarks of their respective owners (Nintendo Co., Ltd., The Tetris Company, etc.). This project is not affiliated with, endorsed by, or sponsored by Nintendo.

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Features 🚀

Core Emulation

• CPU (SM83): Full implementation of the instruction set, built from scratch with cycle-accurate timing.
• PPU (Graphics):
  • Pixel-perfect rendering (160x144).
  • Supports Background map, Window overlay, and Sprites (8x8 & 8x16).
  • Precise VBlank/HBlank timing and LCD status interrupts.
• APU (Audio):
  • 4-Channel Audio: Square 1 (Sweep), Square 2, Wave, and Noise.
  • Full volume envelope and frequency sweep implementation.
  • Audio sync algorithm to prevent crackling on modern hardware.
• Timer: Accurate DIV, TIMA, TMA implementation including "falling edge" behavior (critical for Tetris RNG).

Cartridge Support

• ROM Only: 32KB games.
• MBC1: Bank switching logic.
• MBC3: Advanced banking.
• MBC5: Modern Game Boy games support.
• SRAM: Battery-backed saves (.sav files are compatible with other major emulators).

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Installation & Usage 🎮

Prerequisites

You need to have Rust installed. If you don't have it, get it at rustup.rs.

Building from Source

git clone [https://github.com/lear94/rustygb.git](https://github.com/lear94/rustygb.git)
cd rustygb
cargo build --release