> V6, as distributed, had no networking at all. There are two V6 systems with > networking in TUHS: > > https://minnie.tuhs.org//cgi-bin/utree.pl?file=SRI-NOSC > https://minnie.tuhs.org//cgi-bin/utree.pl?file=BBN-V6 > > The first is an 'NCP' Unix (unless unless you have an ARPANet); the second is > a fairly early TCP/IP from BBN (ditto, out of the box; although one could write > an Ethernet driver for it). I’ve also done a port of the BBN VAX stack to V6 (running on a TI990 clone), using a serial PPP interface to connect. Experimental, but may have the OP's interest: https://www.jslite.net/cgi-bin/9995/dir?ci=tip > There's also a fairly nice Internet-capable V6 (well, PWB1, actually) from MIT > which I keep meaning to upload; it includes SMTP, FTP, etc, etc. I also have > visions of porting an ARP I wrote to it, and bringing up an Ethernet driver > for the DEQNA/DELQA, but I've yet to get to any of that. I’d love to have a look at that and compare and contrast the approaches. I’m finding that BBN’s original design, with a separate kernel thread for the network stack, is elegant but difficult to tune: too much priority and it crowds out user processes, too little and the slow PPP line is not kept busy. I think I’m beginning to understand why CSRG (and later also BBN) moved to the interrupt driven structure of 4.2BSD: perhaps it was also difficult to tune for a VAX with ethernet.