If there was any RFC734 supdup in BSD, then I'm
guessing that would have
been a different one written by David Bridgham. The PC/IP one seems to
be targeted specifically at MS-DOS, although cross compiled from BSD.
Maybe Bridgham was involved in that one too, though. I have asked, and
will report back.
Bridgham answered:
"I wrote both of those clients as well as the BSD server. That's long
enough ago that I don't recall if I shared any code between them. I
don't think did, other than the fact that I wrote both so they probably
share similarities just because of that."