The History of UNIX 1975-1984

Thanks to Chris
for this link.

Ian Darwin and Geoffrey Collyer have written A History of UNIX
before Berkeley: UNIX® Evolution, 1975-1984

It explains how some of UNIX commands were created and who was
involved in various parts of the Genesis of UNIX.

“This article traces some of the intermediate history of the
UNIX Operating System, from the mid nineteen-seventies to the early
eighties. It is slightly updated from an article that appeared as
“The Evolution of UNIX from 1974 to the Present, Part 1” in
Microsystems[Darw1984a]. It was intended as part 1 of 3;
unfortunately, that issue was also the last issue of Microsystems.
This article discusses “Research UNIX”: V6, V7 and V8; and tells
the tale of many programs and subsystems that are today part of 4.4
BSD, System V or both. Subsequent articles were planned to discuss
in more detail the history of Berkeley UNIX, System V, and
commercialized UNIXes. We have not written those other articles;
this article is being submitted to DaemonNews in hopes that those
who have written other histories of other parts of UNIX’s history
will come forward.”