Look again. The colophon in my copy of The UNIX Programming Environment
(first paperback printing of the first edition) says
This book was typeset in Times Roman and Courier by the
authors, using a Mergenthaler Linotron 202 typesetter driven
by a VAX-11/750 running the 8th Edition of the UNIX operating
system.
I don't have a copy of the latter-day (now contains ISO) C book, but
if I recall correctly when it was written, it was probably typed in
on a VAX 8550 running the 9th edition system. Probably it was the
latter-day 9th, which had crept along quite a bit beyond the hasty
9/e manual. After I made some radical changes to the way device
drivers plugged into the kernel, I changed it to print `9Vr2' when
it booted, partly to distinguish the old system from the newer one
and partly to annoy enough people to reach critical energy to produce
a 10/e manual. The tactic took a while but was ultimately successful.
For those who don't know the historic chain, the systems loosely
called V8, V9, and V10 were never real releases in any sense; they
were just names hung on the continuously-evolving system we ran in
the 1980s in the Computing Science Research Center at Bell Labs.
Brian and Dennis and Rob (and, for six years, I) used that system
for everyday work as well as as a sandbox for systems work; hence
the credit in the books. There were tapes called V8 and V9 issued
to a few specific places under special on-off letter agreement, but
they correspond only approximately to the like-numbered manuals.
Norman Wilson
Toronto ON
(which feels a lot like New Jersey this evening)