I just got on this list today, and I see that Larry McVoy asks:

"I wish Marc was on this list, be fun to chat."

I'd be happy to chime in on SCCS or early PWB questions, to the extent I remember anything.

I did see a thread about PWB contributions in which people are trying to sort out what came from research and what from the PWB group (under Evan Ivie). As I recall, PWB was always based on research. Dick Haight would install the latest research system from time-to-time, and then the so-called "PWB UNIX" was whatever he had taken from research plus stuff we were developing, such as SCCS. Unlike, say, Columbus UNIX, our kernel always matched research at the system call level, so there never was such a thing as a PWB-kernel dependency.

(I think the USG system was run quite differently: They had their own system, and would merge improvements from research into it. I could be wrong about this, as I never worked in the USG group.)

--Marc