2014 12 16 was bugged and was quickly replaced by 2014 12 19 so don't worry about that. A copy of 2014 10 24 can be found here, but make sure you heed the warning!

20141024 firmware contains broken reset button functionality. If you set network settings wrong or are unable to access to the UI/SSH, the controller is considered unrecoverable and bricked. It will have to be sent back to Bitmain to be reflashed manually. Use at your own risk.