The serial ports for the different radios is normally an RS 232 connection (I have used a converter in the past).
I have been studying this problem and found out that basically I need a serial to USB converter if I want to try communicating through USB to the radio. However apparently there is A fair amount of complexity with the HMI interface, drivers, etc.
This particular radio, and ICOM IC-705 also has a Bluetooth interface so I am planning on trying that. My only quandary to get started is how to set up the Arduino IDE to download to the ESP32 board. I’ll have to figure that out.
Thanks for the reply.
Sir Michael