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