Just stumbled over another early TCP/IP for Unix:
http://bitsavers.informatik.uni-stuttgart.de/pdf/3Com/3Com_UNET_Nov80.pdf
It would seem to be a design similar to that of Holmgren's (NCP-based) Network Unix
(basic packet processing in the kernel, connection management in a user space daemon). In
time and in concept it would sit in between the Wingfield ('79, all user space) and
the Gurwitz ('81, all kernel) implementations.
I think it was distributed initially as a mod versus V7 and later as a mod versus 2BSD.
Would anybody here know of surviving source of this implementation?
Thanks,
Paul