How to replicate the old unix chat?

[joe at actionline.com]

About a hundred years ago, on an old Tandy 6000 unix system that I had,
there was a command line 'chat' utility that allowed an interactive 'chat'
between a host computer and a terminal logged in to the host. It was much
simpler, faster, and (to my mind) more efficient than any graphical 'chat'
program I have seen ... so, I wonder if there might be a way to replicate
that on a current Linux system?

On my current system, in /usr/bin, I see chattr and xchat and in /usr/sbin
I see chat, but I don't know how they work. (I know, I need to try to find
and decipher a 'man' page, and I will.) But just wondered if anyone on our
list knows which, if any, current 'chat' utility works the way the old
unix command line 'chat' worked.

It just allowed two (or more) parties to be "on the same page"
simultaneously and everything that anyone typed appeared on the screen
(and the entire exchange copied to a file).  It was great because anyone
could jump in while another person was typing and (politely) interrupt,
even in mid-sentence. For cooperating folks that worked very well because
no one had to wait 'til another person finished and hit <Enter> to add
something. Our convention was, if someone wanted to "jump in," they would
just type an elipsis (...) and the currently writing party would know that
someone else had something to insert.

I'd like to be able to use this again with one of my team, if it is still
available somehow.