On 2019, Dec 6, at 12:33 PM, Noel Chiappa <jnc@mercury.lcs.mit.edu> wrote:

From: Lars Brinkhoff

PARC's MAXC appears in the mid-1970s.

Maybe this is a good time to ask if anyone knows whether any of those
diverse systems has software preserved? Specifically, the
implementation of the NCP and 1822 Host-to-IMP protocols?

Both MAXC's were PDP-10 re-implementations, and ran TENEX. So the basic
system is still around, not sure if they had any interesting local hacks
(well, probably PUP support; MIT tried to put it in MIT-XX, so it may
still exist on thats backup tapes).


I am pretty sure that the NCP implementation for the MAXCs was the TENEX version, with local mods by Ed Taft.

I designed the Alto BBN-1822 interface, which was used for connecting to the  Bay Area Packet Radio network and also used for PARC-MAXC2.  MAXC1 had a Nova as the front end, about which I know nothing, but MAXC2 used an Alto. Both machines were  40 bit word microcoded machines programmed to be PDP-10s.  Corporate wanted PARC to use SDS but the CSL folks wanted a 10, so they had to build one.

The software specifically for the Alto 1822 survives, oddly enough, because Marc Verdiell (CuriousMarc)’s 
Alto Restoration project showed my old 1822 development disk pack in  https://www.youtube.com/watch?v=LxFv2JNNW-A  I found the bits at 
http://xeroxalto.computerhistory.org/Indigo/Alto-1822/.index.html

I only tested my own code up to successful loopback to the local IMP, then Ed took over.  I did the low level code for the PRNet interface, which was not NCP, and hooked it up to  Hal Murray’s Mesa implmentation of the Pup stack.

-Larry