PDP-11 info needed.

From: Allison J Parent <allisonp_at_world.std.com>
Date: Wed Jul 8 18:52:30 1998

At 00:26 08-07-98 +0100, ard_at_p850ug1.demon.co.uk (Tony Duell) wrote:
< On another subject, in several of the PDP machines here there's an M7856
< module (the DL11-W option) designated as "SLU and realtime clock". What
< exactly does SLU mean in this case? Serial Line Unit?

Correct SLU= serial line unit and a DLxxxx is a standard serial interface
for PDP-11 software.

< "CONSOLE". It does have a cable running from the module connector out to
< 25pin "D" connector bolted to the back of the cabinet which in turn has a
< ten or 15-foot cable attached.

Yep, serial console usually a printing console (la120) as printed logs
go to console for some OSs (rsts and RSX-11)
 
< There are a group of 16 D25 connectors on the back panel of the machine
< (cabled to the two M7819's) obviously for the user terminals. Unlike the

Yes, user serial lines one per.

< IBM 9370 and HP 250/30 machines I have, on which the operator's console i
< attached to one of the corresponding group of user terminal connectors, i
< seems there typically is a separate serial console connector for the DEC
< world just for the system operator. Is my thinking correct here?

The system console is a unique device and all (rare exceptions) pdp11
systems expect it and its address and interrupt will always be the same.

< The second M7856, what could that be for? The cable attached to that othe
< M7856 has a connector on the other end with, IIRC, 6 or 7 pins inside a
< flat, white nylon shell. Length of the cable is about three or four feet.
< The nylon shell end connects to nothing that I can see anywhere.

another serial line with a current loop (20ma) for some terminal or printer.

Allison
Received on Wed Jul 08 1998 - 18:52:30 BST