FCEUX is available here
You will need to find the Super Mario Bros rom for the NES to be used in the emulator. It is up to the reader to locate said rom by their own means.
You will also need the movie we will be playing back which will beat the game. That can be found on the NES movie list
at TASVideos . Look for "NES Super Mario Bros (JPN/USA PRG0)", but feel free to try out any movie that plays Super Mario Bros. At the time of writing this article, this
movie, made by HappyLee, is currently the fastest Super Mario Bros completion the site has.
Which ever movie you choose, download the .zip file containing the .fm2 file that is the movie.
You will next need the Lua code which will modify the movie for playback on the console. This code will remove any lag frames from the movie file, and the button data in the same directory as the .fm2 file. Download this code and save it somewhere convenient.
Open the emulator and load the rom into the emulator, and press the pause key on your keyboard to pause the emulator. Open a new Lua window (File - Lua - New Lua Script Window), and browse to the lua script you downloaded. Press run.
Then load the movie you downloaded. Go to File - Movie - Play Movie. From the drop down list pick Browse..., and navigate to the movie you downloaded. Press the pause key again to unpause the emulator, and let the video finish playing. If you'd like, you can speed up playback by pressing + or holding the tab key for turbo.
When the movie is finished, pause the emulator again, and stop the Lua script.
You should now have another file in the same directory as the .fm2 file. We will need this later.
We will next load the code onto the arduino.