On Fri, Sep 13, 2019 at 05:45:51PM -0400, Clem Cole wrote:
>    It does leave us an interesting question, when did the original roff(1)
>    show up and when did nroff(1).  The original, roff(1), was early, and
>    of course not until after the original PDP-11/20 port.  But was it as
>    early as first edition?   roff was the first formatting program.  nroff
>    replaced it later on, although roff lived through the 6th edition (I do
>    not believe it is on the v7 tape).

There was a roff on PDP-7 Unix:

    By the spring of 1971, it was generally agreed that no one had the
    slightest interest in scrapping Unix. Therefore, we transliterated
    the roff text formatter into PDP-11 assembler language, starting from
    the PDP-7 version that had been transliterated from McIlroy’s BCPL
    version on Multics, which had in turn been inspired by J. Saltzer’s
    runoff program on CTSS.

>From "The Evolution of the Unix Time-sharing System"

http://www.read.seas.harvard.edu/~kohler/class/aosref/ritchie84evolution.pdf

Cheers, Warren