Mutant01 IP = 205.138.39.180

From: John Wilson <wilson_at_dbit.dbit.com>
Date: Wed Mar 15 15:02:47 2000

On Wed, Mar 15, 2000 at 06:35:58PM +0000, Tony Duell wrote:
> > Anyone here have any vintage software to run on a PDP-11 as a front end
> > connection server? Waterloo University used a PDP-11/45 back in the '70s in
> > front of their *huge* cluster of some 3-500 DEC minicomputers. I've got
> > heaps of DZ,DL,etc.. from the warehouse so serial ports are not a problem.
>
> Cambridge Universtiy (UK) did something similar as a frontend to their
> IBM 3084 mainframe.

RPI did the same kind of thing on their mainframes (3033, 3081D, 3090,
ES/9000). The first system (since I was there) used PDP-11/34(s) and was
called simply the FEP (front end processor), it was dependent on the host
system for help with scrollback buffers etc., so if the mainframe went down
so did the FEP. Then later they switched to a bunch of 11/73s called NIMs
(network interface machine), running software developed at UBC (in the
PLUS programming language, for which a PDP-11 cross-compiler existed on the
mainframe). They had lots of their own memory and were independent from the
mainframe, essentially they were big fat terminal servers. IIRC they spoke
X.25 to the mainframe (with the "VTP" virtual terminal protocol running on
top of that, or optionally X.29 (??)), but they also could do TCP/IP for
talking to everyone else.

But I don't understand what the goal is here. Just a reverse terminal server
to hook up to a bunch of non-TCP/IP-aware PDPs using serial lines? I don't
know of anything like that, although it shouldn't be *that* hard to write.
I've never played with the MINITS system but AFAIK it's just some kind of
TAC system, maybe it could be turned around backwards and adapted for this?
Anyway last time I put a non-TCP/IP-aware PDP-11 compatible system on the
net I just used a Linux box with a version of telnetd hacked to use serial
ports instead of PTYs, it's cheating but it was very fast and at least it
spoke "modern" TCP/IP.

John Wilson
D Bit
Received on Wed Mar 15 2000 - 15:02:47 GMT