HOWTO: cups config for printer on Netgear PS121 print server

A while ago I bought one of these Netgear print servers and had a real
problem configuring cups to use it. So, after a search I found the
firmware for the gadget at the Netgear site and hexdumped it. Doing a
cursory study I found that the default print queue seems to be P1.
Although nmap shows that a cups server is alive at port 631, attempts
to configure cups using IPP failed (for me), for example, test pages do
not print. But configuring as lpd worked. The magic string is:

lpd://<put IP of PS121 here>/P1

I'm posting this in the hope that it will help some other Linux users
who have this device.

Regards, Bob L.