This was wildly helpful. I found an Atari Flashback Blast! controller without an HDMI dingle for 50¢ at a thrift store and was hoping I could find a way to use it. Not only can I do that, but I can use it as the P2 controller to the $1 Blast...
sorry, beein trying to find this file that's been right in front of me for a month now, only to find broken links, and google to prove that it's completely worthless.