AT&T "nth Edition" vs. "Release n"

[Guy Harris]

>System V derives from System III which derives from 6th edition (or there
>abouts).

No.  System III derives from UNIX/TS 1.0 or some such thing (I *think*
PWB/UNIX 2.0, or whatever the UNIX release between 1.0 and 3.0 was
called, got in there somewhere; System III was 3.0.1 or something near
to that), which had quite significant V7 content (e.g., the file system,
the "stat()" call, environment variables, Bourne shell), although it had
a V6-flavored tty driver.  System III also had a fair bit of PWB
content. 

(Note: when I say "V7 content", I mean that the items in question first
appeared *in widely-available releases outside AT&T* in V7.  The branch
of the family DAG that contains UNIX/TS 1.0, S3, and the S5 releases
probably first split off from the Research branch before V7, but after
the V7 file system first appeared.

And no, I said "family DAG", not "DAG's family"; as far as I know, Doug
is the only member of the Gwyn family involved with UNIX. :-))