PDP-11 info needed.

At 00:26 08-07-98 +0100, ard(a)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