I first learned original TECO-based EMACS on the Stanford CERAS DECsystem-20/60 running
TOPS-20 during the summer of 1978 - I'd been using line-editors before that, and
EMACS was a revelation. Heck, "intelligent" (CRT) terminals were a terrific
replacement for teletypes, DECwriters, and "glass" TTYs.
When I got to UCB in the fall of 1980, it took until Winter quarter (1981) to get an
account on the Cory Hall (EECS) PDP-11/70 running 2.8 BSD Unix, through the Berkeley
Computer Club. The Warren Montgomery emacs was available, and since I already knew emacs
keystrokes, that was my editor of choice ... initially. I converted to vi because I really
hated having one finger on the CTRL key all day long.
It was also nice that the BSD tty line discpline displays what you type along the same
lines as TOPS-20 did, including word-erase, though trying to use ^W that way in most emacs
absolutely violates the Principle of Least Astonishment ... which if you've ever
interacted with rms, should not really surprise given what he did with ^S, ^Q, and ^H.
Emacs has been available (in one form or another) on Unix for a very long time.
Erik