GoNES

An NES emulator written in Go.

Install

Homebrew (macOS)

brew install gabe565/tap/gones --no-quarantine

Binary

Automated builds are uploaded during the release process. See the latest release for download links.

Web

GoNES supports emulation in a web browser by compiling to WASM.
A hosted instance is available at gones.gabe565.com.

From Source

Click to expand

Requirements

Rendering uses hajimehoshi/ebiten which requires OpenGL development libraries to compile. See ebiten install steps.

Installation

Make sure you have Go and the requirements installed, then run:

go install gabe565.com/gones@latest

Usage

Application

When started, GoNES will open a file picker. Choose the .nes file to start emulation.

Terminal

Click to expand

GoNES also supports being launched from a terminal.

gones ROM_FILE

See docs for the full command line usage documentation.

Configuration

A configuration file will be generated the first time GoNES is run. Depending on your operating system, the file will be available at:

• Windows: %AppData%\gones\config.toml
• macOS: ~/Library/Application Support/gones/config.toml
• Linux: ~/.config/gones/config.toml

An example configuration is also available at config_example.toml.

Keybinds

Keys are configurable, but the default values are listed below.

Player 1

Nintendo	Emulator
A	M
B	N
Directions	WASD
Start	Enter
Select	Right Shift
A (Turbo)	K
B (Turbo)	J

Player 2

Click to expand

Nintendo	Emulator
A	Num Pad 3
B	Num Pad 2
Directions	Home/Del/End/PgDn
Start	Num Pad Enter
Select	Num Pad Plus
A (Turbo)	Num Pad 6
B (Turbo)	Num Pad 5

Other

Action	Key
Save State	F1
Load State	F5
Undo Save State	Shift+F1
Undo Load State	Shift+F5
Fast Forward	F (Hold)
Reset	R (Hold)
Toggle Fullscreen	F11
Screenshot	\

Debugging

Click to expand

Action	Key
Toggle step debugging	`
Toggle stdout trace log (when step debug enabled)	Tab
Step to next frame	1
Run to next render	2

Milestones

• CPU implementation
  • CPU is stable, and nestest.nes passes.
• Cartridge implementation
  • Support for mappers
  • Common mappers implemented
    • Supported mappers: 0, 1, 2, 3, 4, 7, 69, 71 (84.34% of official NES games)
• PPU implementation (graphics)
  • Background rendering
  • Sprite rendering
• GUI
  • Rendering works, but menu options need to be added.
• Basic controller support
  • Player 1
  • Player 2
  • External controllers
• APU implementation (audio)
• Save file for games with batteries
• Save states
• Configuration (remap controllers, video config, sound config, etc)
  • Config file
  • Config UI
• Cheats

References

• NESDev wiki
• NESDev 6502 Reference
• NESDev Undocumented Opcodes
• Writing an NES Emulator in Rust
• fogleman/nes
• ltriant/nes
• i82orbom/nesgo
• No-Intro
• NES Composite Palette Project