Through bus snooping using a Saleae Logic 8, we determined:
The official software required is Motorola GM950 RSS (Version R02.00.00 or higher) . This is a DOS-based application. It is text-driven, non-graphical, and relies on function keys (F1-F10) for navigation.
Because the software is proprietary and old, obtaining it is the hardest part of the process. Motorola Gm950 Programming Software
If you have spent three hours trying to force a USB adapter to work in DOSBox and are ready to throw the radio out the window, consider these alternatives:
CPS Crashes or Fails to Read
Incorrect or Missing Features
Corrupted Configuration After Write
Driver Issues (Unknown COM Port, Code 10)