I'm having problems with compatibility. Have not been able to have Tx function cause the transmitter to transmit but I do get receiving working OK. I note comment about drivers not available for HRD which would be the program of choice.
No problem with HRD, at least not the current paid version. Just create a PTT port in CAT and set DM780 to use that. Set the mode to DIGU, and select the DAX button for transmit and you should be good to go.