Don’t know, there was the “brain damaged” Hazeltine mode even in V6. I suspect there
were a lot of random things kicking around that got hooked up after the initial model 33
and 37 ttys.
I’ve found several early pictures, one of Ritchie, and another of Thompson (though Ritchie
is in the background) sitting with what appear to be Tektronix 4014s.