Well, others have made it work. In your original post there is no mention of using the Mac, so that does change thing a little, but it doesn't mean you won't get it working... others certainly have. AFAIK, most of us here use Windows and/or Linux. Just a mild suggestion (and a reminder to myself) the PC in use information is critical.

Do not despair, you got an excellent USB to serial adapter, and that is a big deal.

I'm a winders guy for ham radio stuff, mostly because I use a Flex 3000.

FLRIG is good to have (and many times necessary) as it will diagnose what's going on. You will need to have the XML-RPC part configured correctly, but again, others have done this. Now, I'm a little in the dark, as I don't run a MAC, but computers are just computers.

From other places on the web, a quick search shows this:

Download page for XML-RPC :
https://sourceforge.net/projects/fldigi/files/xmls/

From other forums, there is a bit of background noise as it is for a Kenwood on OSX, but pertinent info here:
https://www.ar15.com/forums/t_10_22/...g_on_OSX_.html

Lastly, the nitty gritty to talk to the Keyspan port at a "low level". You may not have to do this.

But even if the computer "sees" the port, it may not be configured to "talk":
http://kb.unavco.org/kb/article/how-...cable-505.html

A call to other Islanders, who's running this on a MAC? Anybody? Buehler? ;)