Or should I have said not before December, to manage expectations better? I am making baby steps and haven't accomplished anything to show yet.I looked at it today and I think I can write a new gmc300 app based on this.
One HUGE caveat: I am chronically lacking spare time.
I will order one or another GQ GMC and then try this. But don't expect any real progress before November.
One thing which dawned on me is that I probably should concentrate on getting something up and running on Linux first, and not distract myself with questions of portability to Windows for the first stage. It looks like a port to Windows will either require quite some extra code, or moving the application from MinGW (which was used by the Radac developers so far, AFAICT) to Cygwin. Windows' lack of a POSIX programming interface to properly open COM ports might be the reason why the existing gmc300.exe doesn't work unless one first accessed the GMC via a different GQ GMC compatible program.