5 Mar
2026
5 Mar
'26
7:32 a.m.
On Mar 3, 2026, at 9:36 PM, Phil Budne via cctalk
<cctalk(a)classiccmp.org> wrote:
Paul Koning wrote:
The front end thing is called "intercept" which implements a rudimentary form of
routing documented in an appendix of the Phase II spec. PyDECnet implements it (in a
branch at least; I forgot if it's released yet).
But that doesn't use the A::B::C stuff you mentioned. That's a different
mechanism handled in the application (in some of them) using a DEC internal object called
PMR (poor man's routing) or PSTHRU. That actually was carried over all the way to
Phase IV within DEC in order to access "hidden areas".
Some applications would get equivalent functionality a different way. For example, it
would work in DAP if the intermediate node was VMS, because VMS (RMS32) has transparent
network access.
paul
NCP as a standardized element, with its protocol
NICE, arrived in Phase III. I was somewhat surprised to find a predecessor of both the
program and the protocol in Phase II for TOPS-20
I'm 99.44% sure that in Phase III days both PDP-10 operating systems
were still non-routing Phase II nodes with only one link to a
dedicated front end PDP-11 (via the DTE hardware that could handle
upto four). Before Phase III everything had to be manually routed,
A::B::C -- I forget the name of the passthru service that facilitated
that.