OK, I can see it working better in principle, but, without software
writing, how do I do it???

I've never seen a PSK modem chip. I had a tough time finding an MSK
chip! It seems that software is the only presently accepted way to
create a psk decoder. I have googled for PSK MODEM, and found mentions
of it, but I cannot find a hardware solution.

Do you know of a chip that does it (public domain)?

Thanks.

Art