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DEC/X11

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pbirkel@gmail.com

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What does the expression "DEC/X11" designate? I've come across this referent on multiple occasions now and they don't seem to add up to any coherent context other than that the expression doesn't seem to relate to any specific system, system configuration, or hardware option ... although in general it seems to be hardware-related.

While the DEC-developed Unix-based X11 Windows software-system is often referenced as "DEC/X11" I have encountered the expression in many contexts that (IMO) have absolutely no, even distant, relationship to the X11 Windows software-system.

I'm befuddled regarding alternative meanings for "DEC/X11". Can someone please "put me in the picture"?

- paul
 
Aghh I remember that..
To save others a bit of reading... It allows you to build a diag exerciser for (usually / almost) all the XXDP diags for a specific PDP-11 hardware config and test most of the system at once for a good simulation of real world use, rather that running one diagnostic at a time...

Takes a bit of setting up - but was a very good overall soak test for a complete system.

I think it uses a different version of the diag tests (different file extension) rather than the ones run individually...

Robin
 
I see that this got answered. A diagnostic exerciser was my best guess was based on seeing DEC X8 running on what would eventually become my Straight 8. This was in 1975 or 76 and the service tech was repairing the DF-32 and when all done ran this. I had never seen the machine look so busy. What struck me at the time was that all three DECtape drives were spinning at the same time which never happens in normal use. I need to run down a copy and figure out how to run it. I asked if I could get a copy but at the time he would not let it out of his sight. I would imagine that the 11 version was closely held as well.
 
DougIngraham said:
I see that this got answered. A diagnostic exerciser was my best guess was based on seeing DEC X8 running on what would eventually become my Straight 8. This was in 1975 or 76 and the service tech was repairing the DF-32 and when all done ran this. I had never seen the machine look so busy. What struck me at the time was that all three DECtape drives were spinning at the same time which never happens in normal use. I need to run down a copy and figure out how to run it. I asked if I could get a copy but at the time he would not let it out of his sight. I would imagine that the 11 version was closely held as well.
Click to expand...

To my knowledge DEC/X11 was distributed with the same rights and restrictions as were all the other DEC XXDP diagnostic binaries and listings.
DEC/X11 basically consisted of a linkable .OBJ file for each device to be exercised, and they were all combined with the master control program to create a custom exerciser image for a given system configuration.
The standard DEC XXDPv22 and XXDPv25 diagnostic packs contained all these .OBJ files.
The documentation in .PDF is available under here: http://bitsavers.org/pdf/dec/pdp11/xxdp/ including listings for each .OBJ module.

Maybe DEC/X8 was treated differently, but I really would not think so, given PDP-8 diagnostics were delivered the same way PDP-11 were.
I think more likely it was a quirk of that F/S guy.
 
I would think that given how our aged hardware fails over time that it would be useful to be able to run a single "all systems check" after a period of power-down, rather than wait for anomalous behavior and then start a differential diagnosis procedure. Maybe setting up a configuration-specific exerciser is just too painful compared to the anticipated system confidence by being able to run it as needed/desired? Did commercial installations run a system exerciser on a regular basis as part of a PM plan?
 
I looked after several 11/70's in late 80's to early 90's running RSX-11m. After any odd failures we would run IOX (I/O exerciser) that was on the RSX-11m boot disk.
 
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