[Simh] IMP interfaces

[Phil Budne]

> >Can the IMP software and the H316 simulator talk TCP/IP to an ehernet card?

If we had TCP-era IMP code, one could, in theory, but as I recall the
structure of the TCP ARPAnet (net 10) address was that one octet was
the IMP number, and another the port on the IMP, which was severly
limited (four host ports?), and if that limitation was "well known"
you might only be able to attach to four hosts over Ethernet.

Most often, the system attached to the IMP acted as a router, and
connected to the local internet.