Fearless-NES

Fearless-NES is a work-in-progress Nintendo entertainment system emulator written in Rust.

Screenshots

Features

• Cycle-accurate CPU emulation
• Accurate PPU emulation
  • Mostly cycle-accurate, but has some timing bugs
• Good APU emulation
  • Uses the blip buffer
• Basic mapper support
• Basic GUI
  • currently using egui
  • the code is a bit of a mess currently
  • immediate-GUI seems to be great for simple data visualization or simple GUIs, but making a full app with it is quite cumbersome
• Save states
• Gamepad support
• Controllable overscan
• Game loading using the NES 2.0 XML Game Database
• Custom key bindings

Build instructions:

1. Build with cargo run --profile=release-lto and enjoy !

Accuracy

For accuracy tests, see TESTS.md. Run these with 'cargo test'.

Supported mappers

Mapper	Example Games
0 (NROM)	Super Mario Bros, Donkey Kong, Balloon fight
1 (MMC1)	Final Fantasy, Legend of Zelda, Mega Man 2
2 (UxROM)	Castlevania, Mega Man, Contra
3 (CNROM)	Solomon's Key, Arkista's Ring
4 (MMC3)*	Kirby's Adventure, Mega Man 3-6, Ninja Gaiden II: ...
7 (AxROM)	Battletoads, Jeopardy!
69 (FME-7)	Batman: Return of the Joker, Gimmick!

• Some MMC3 games have graphical glitches.

With these mappers, Fearless-NES should support 84 % of commercial NES games.

TODO

• (frontend) user-defined RGB palettes

• (frontend) NTSC / xBRZ filters

• (core) iNES 2.0 support

• (core) advanced mappers such as MMC5, VRC2/4...

• (core) various accuracy tests

Controls

Keyboard

NES controller	Keyboard
A	F
B	D
Select	Space
Start	Enter
Up	ArrowUp
Down	ArrowDown
Right	ArrowRight
Left	ArrowLeft

Gamepad