There is a later patch release of 2.9BSD that includes TCP/IP support but I have not had any luck getting a compiled kernel to boot. My recommendation would be Ultrix 3.1 which does run on the smaller machines.

I think it is possible that 2.10BSD could be made to work but I have never had any success booting it in SIMH. If anyone has booted it or has any suggestions, I would be interested to hear it.

-Henry

On May 19, 2017 11:15 AM, "Noel Chiappa" <jnc@mercury.lcs.mit.edu> wrote:

I'm trying to find out if there is any existing Unix for the PDP-11
which supports TCP/IP on /40-/34-23 class machines (i.e. non-I+D
machines)?

Does 2.9 BSD with TCP/IP (assuming such a thing exists) fit on those
machines? (I know 2.9 does run on them, but I don't know about the TCP/IP
part.)

The reason I ask is that MIT did a TCP/IP for V6 which would run on them
(only incoming packet de-mux is in the kernel - the TCP is in with the
application, in the user process), which has recently been recovered from a
backup tape.

I'm trying to figure out if there is any use for it, as it would take some
work to make it usable (I'd have to write device drivers for available
Ethernet cards, and adapt an ARP implementation for it).

Noel