I’ve been using MacDoppler for quite a few years. Right now, it’s running on a 9 year old iMac. I also have MacDoppler running on an older (pre Intel) Mac PowerBook G4. I’m only using the program to control the 5400 rotor. I’ve found the program easy to use... update keps using the apps’ pull-down menu, select a satellite, and operate. Bill N5ALO