Download this template .csv file which you can use to fully customize your 30-team roster. Share your rosters and check out others on reddit.
For help on formatting the .csv file, visit the help page.
Tip: The above spreadsheet, without any modification, will generate an end-of-2013 season ROM file.
This is most definitely a work-in-progress. If you find something that is broken or not behaving as you'd expect, or if you can envision a killer feature, please submit an issue to our Google Code issue tracker.
Upload a copy of the original 1990 R.B.I. Baseball 3 ROM, along with your .csv file. Declare a filename for your modified version of the game. Hit "Upload" and you should have your ROM in seconds!
Tip:The R.B.I. Baseball 3 ROM you're looking for is about 192 kB. Other files are not going to work. You should be able to find a copy quite quickly on your favourite search engine.
Maybe you're playing someone's excellent R.B.I. Baseball 3 ROM that was generated with our tool, and you'd like to tweak the lineup or adjust some parameters. This tool will accept a .nes file and return to you a .csv file, that you can tweak and feed back into the gamefile generator above.