[TUHS] Unix NCP protocol stack for ARPANET

Clem Cole clemc at ccc.com
Mon Oct 25 03:24:34 AEST 2021

On Sun, Oct 24, 2021 at 12:57 PM Lars Brinkhoff <lars at nocrew.org> wrote:

> Has any other NCP implementation for Unix survived?  From old host
> tables I think there may have been some VAXen online before the switch
> to TCP/IP.
Hmmm... I find that interesting because  Stan Smith and I wrote the
original IP/TCP for the VAX in 1979/1980 when we were at Tektronix(in
BLISS-32, BTW -- which I gave back to CMU, and CMU added mailer and
eventual DNS support, and then distributed it as the Tek-CMU TCP/IP - DEC
eventually used it to start their in-house effort - I have that code on
9-track and may have it on a CD somewhere).   When Stan and I started that
work, I had looked everywhere I could think to find an NCP implementation,
and never found one.   Our Vax was connected to the Teklabs 11/70 running
V7 and the 3Com UNET stack that Bruce Bordan and crew wrote.

The reason was that IMP's ports were a rare commodity and free ones almost
non-existent.  So when Vaxen started to roll out, the IMPs were
usually filed with PDP-10s at the research sites.   Vaxen also tended to
have Xerox 3M Ethernet boards.  I also don't know of anyone connecting a
DR-11B to an 1822 for a Vax - could have been done, but I don't know of
one.   At both CMU and UCB, we used Xerox boards until the real ones from
3Com, Interlan and DEC showed up and that was not until 1981-82 and the IP
transition has already begun.

You tell me, but I was under the impression, that you folks at MIT did a
ChaosNet interface, IIRC, so there may have been some sort of conversion on
your LAN, but I really doubt there was a real NCP running.

FYI: CMU had Vax serial #1, and it was never on the ARPAnet.  It was in the
same machine room as the IBM 360s, PDP-20s, and Univac 1108, not the CS
PDP-10s where the IMP was.

My guess is that people had Vaxen assigned in the host tables, but never
connected for lack of an NCP implementation.  And until the Tek stack for
VMS and the BBN stack for 4.1 BSD, I don't think there were any Vaxen yet
on either the NCP based ARPAnet much less the later IP-based one.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://minnie.tuhs.org/pipermail/tuhs/attachments/20211024/76f4bd12/attachment.htm>

More information about the TUHS mailing list