[COFF] [TUHS] conventions around zero padding in ip4

[Lars Brinkhoff]

Noel Chiappa writes:
> [The Terminal Interface Unit TCP/IP] is an interesting implementation,
> because it was definitely one of the first 4 TCP implementations done
> (before any UNIX ones); likely one of the first two, along with the
> TENEX one.

Any idea when the TENEX implementation was made?

These files seem to be from 1982:
https://github.com/PDP-10/tenex/blob/master/135-tenex/tcpip.mac