zetr - nes emulator

A Nintendo Entertainment System (NES) emulator written in Rust. Currently supports basic ROM loading and CHR data visualization.

features

• iNES ROM format support
• Full 6502 CPU emulation with 80+ instructions
• Advanced PPU with background rendering
• Authentic NES timing (CPU/PPU sync)
• Complete memory mapping system
• NMI and interrupt handling
• Controller input with all buttons
• 60 FPS rendering with SDL2
• Support for Donkey Kong and other NES games

controls

• Arrow Keys: D-pad
• Z: A button
• X: B button
• A: Select
• S: Start
• ESC: Quit

building

Requires SDL2 to be installed:

# macOS
brew install sdl2

# Build and run
cargo build
./target/debug/zetr <rom_file>

example

./target/debug/zetr donkeykong.nes

current status

This is a functional NES emulator capable of running Donkey Kong and other NES games. The emulator features:

• Complete 6502 CPU: All essential instructions for game logic
• Advanced PPU: Background tile rendering with authentic NES graphics
• Real-time Emulation: Proper CPU/PPU timing synchronization
• Game Controls: Full controller support for gameplay

architecture

• cartridge.rs - iNES ROM loading and memory mapping
• ppu.rs - Picture Processing Unit with authentic rendering
• nes.rs - 6502 CPU emulation and system coordination
• main.rs - SDL2 windowing, input handling, and main loop

future improvements

• Sprite rendering and animation
• Audio processing (APU)
• Support for more mappers (currently supports mapper 0)
• Save states and rewind functionality
• Game-specific optimizations
• Debugger and development tools