[Simh] PCL-11?

[Galen Tackett]

> 
>> Does anyone know anything about the PCL-11 communications stuff
>> and have any plans to implement it?  I can't find too much about
>> it in a quick 20-second look, others will likely fare better.
> 
> I used it on both PDP-11/44 (RSX-11M+) and VAX/780 (VMS) systems
> back in the early 1980s.   I even had to work on the VMS device
> driver so that DECnet would work.
> 
What was the PCL-11? I’m trying to remember if I ever encountered one. (I wouldn’t have anything helpful to offer, I’m afraid—just reminiscing.)

One device I spent a lot of time with, my first year out of college, was the DA-11B, a memory to memory DMA link which we used at Lockheed between several LSI-11 data collection stations running RSX-11S and a PDP-11/60 with RSX-11M that ran a static load test system for us. There were no device drivers for it, or at least none suitable for this purpose, so I wrote the link software we used—partly in Macro-11, of course, but also partly using DECUS C.

A coworker of mine had found a way to use the Connect to Interrupt Vector directive (CINT$) with a program that was mostly in FORTRAN, using some linkage code in Macro. I turned this into something similar for use with DECUS C.

We used a differential-signal version of the DA-11 (maybe that’s what the -B was for?) to go the relatively long distance (for DMA, in those days) from four locations on our big 7 story test stand, into the small computer room located off the 2nd or 4th floor--I forget which for certain, but our office was a room two stories up from that.

As I recall, our DEC Field Service rep. had a bit of work to do, to get this hardware working reliably. There may have been problems involving the flat, wide-ish cables that before installation had been pre-pulled through the trays on the test stand. Perhaps grounding issues?

That was a fun project and a nice challenge right out of college. I constantly had my hands on/in both hardware and software. Ah, the memories...