Small steps. I'm exposing an emulated OPENSTEP 4.2's telnetd to my host macOS. I've learned:
1. It turns out you have to aggressively set TERM=xterm so that macOS telnet can report something OPENSTEP 4.2 understands:
TERM=xterm telnet [IP] [PORT]
2. Once you figure that out, a good AI agent will know what you mean when you say "Run commands on my OPENSTEP 4.2 virtual machine, which I have made accessible via telnet; you login as user: password with TERM=xterm telnet [IP] [PORT]. If you really need to, you can use su with the password [password here], and FTP in on port [port here]".
3. ChatGPT 5.6 makes an enthusiastic but very novice NeXTSTEP sysadmin...
It did teach me, though, that you can get a serial console on an OPENSTEP/x86 host! If you have an emulated serial port, and a corresponding serial device setup in Configure.app, you can also configure a "TTY Port Server" device on Configure.app. Edit /etc/ttys to configure ttya, and bob's your uncle.