Actually, TCP/IP was first implemented internally at BBN, but then once
that proof of concept was done, arpa contracted UCB to do the 
implementation in BSD UNIX. The first TCP/IP implementation outside of the 
totally experimental BBN version was the one done at berkeley, in UNIX, 
on a VAX. I dont think BBN did their initial version on a PDP10. 
The arpa internet itself, however, was indeed originally built with PDP10s
and some even older stuff, running the hello protocol. 

Isildur

On Wed, 7 Mar 2001, Johnny Billquist wrote:

> Have to disagree with you here. Unix was a latecomer in TCP/IP. Try
> PDP-10 for an earlier machine...
> But later day TCP/IP development was indeed done on VAXen running BSD.
> Early Unix networking means uucp. :-)
> 
> 	Johnny