Titan, Thanks for the reply. Reading the LJ4100 manual more carefully, I see it's really a 15-pin and:
"Accessory port for some paper handling accessories (this is not a serial port)."
I guess it would not work for connecting to a computer data path, as I thought.
I have never shared computers, so I will have to poke around about this. I do recall seeing the option, I guess in Control Panel. My LJ4100 does not have an ethernet port, only an empty place for one. If one computer feeds through the other computer in order to print, that means both must be on. That's not optimum, but perhaps the only alternative short of a new printer, and maybe unavoidable next year.
Next year I plan to have an offline W7 computer and an online W10 computer, unless I can find a way to run XP Mode on the W10 computer for a critical DOS database. And I could not find how to activate needed expanded memory in DOSBox. Currently I have two monitors on one computer, and I run XPMode for DOS on one, and Internet on the other for my research. This all gets messy. W7 forever!