Using evolutionary algorithms to let computers play NES
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This project extends the NES emulator from Michael Fogleman to let computers play NES. This repository is forked from .

Evolutionary algorithm iterates through following steps:

  • Use a given button pattern and make random changes (add/remove button presses, cut pieces out of the pattern
  • Let the pattern run in the emulator
  • Rate the success of the button pattern
  • If the actual is better than the original use this pattern for the next iteration


The portaudio-go dependency requires PortAudio on your system:

To build portaudio-go, you must first have the PortAudio development headers and libraries installed. Some systems provide a package for this; e.g., on Ubuntu you would want to run apt-get install portaudio19-dev. On other systems you might have to install from source.

On Mac, you can use homebrew:

brew install portaudio


The go get command will automatically fetch the dependencies listed above, compile the binary and place it in your $GOPATH/bin directory.

go get


nesolution rom_file cmd replay_file

Possible commands(cmd) are:

  • record: play the game and use spacebar to start and end recording to the given replay_file
  • play: replay the button pattern stored in replay_file
  • evolve: optimize the given button pattern


Joysticks are supported, although the button mapping is currently hard-coded. Keyboard controls are indicated below.

Nintendo Emulator
Up, Down, Left, Right Arrow Keys
Start Enter
Select Right Shift
A (Turbo) A
B (Turbo) S
Reset R
Start/Stop Recording Space


The following mappers have been implemented:

  • NROM (0)
  • MMC1 (1)
  • UNROM (2)
  • CNROM (3)
  • MMC3 (4)
  • AOROM (7)

These mappers cover about 85% of all NES games. I hope to implement more mappers soon. To see what games should work, consult this list:

NES Mapper List

Known Issues

  • there are some minor issues with PPU timing, but most games work OK anyway
  • the APU emulation isn't quite perfect, but not far off


Interested in writing your own emulator? Curious about the NES internals? Here are some good resources: