How do you start a newsgroup (NNTP) server?

Back in the old days, when Usenet and Gopher ruled the Earth, I had thought about setting up servers for various things, just in case the urge to be an ISP overcame me.

I managed to figure out how to set up a server for just about everything except NNTP. I mean that I could set up the server for it, but I could never figure out where to get the feed from.

Since I’ve spent the night sleepless again I thought by now there might be enough information out in the wild that would let me know since Usenet isn’t really relevant anymore. I was wrong.

I was wondering if anyone here knew about it. So, if I wanted to lose my mind, where would I go to get an NNTP feed from?