Old Unibus PDP-11 XXDP diagnostics

From: Pete Turnbull <pete_at_dunnington.u-net.com>
Date: Tue Dec 21 13:09:38 2004

On Dec 21 2004, 9:14, Guy Sotomayor wrote:
> On Tue, 2004-12-21 at 08:27, Ashley Carder wrote:
> > Does anyone have any info/documentation on the XXDP diagnostics for
> > older PDP-11 systems and peripherals? I'm looking in particular for
> > the 11/40 (11/35), RK05, DZ11, RL02, MM11 core memory, RX01, RL01
> > diagnostics. I have found some info on Henk's site, but would like
> > know if anyone has a comprehensive list and hints on how to run
> > what the output means, how to answer the prompts, etc.

It would be a big list :-) I had a whole box of microfiche of them,
once. Later diagnostics use a common set of "switches" to tell them
whether to halt on error, loop on erro, produce lots of reports, etc;
alsmost all diagnostics have specific settings to determine what they
do in detail. If they halt on error, you need the isting to determine
exactly what caused the halt -- they don't, in general, print much
informative info.

> OK, the "magic decoder ring" for converting the MAINDECs to XXDP
> is quite simple. The MAINDEC # is of the form:
> MAINDEC-11-Dxxxx-*
> To convert this to the XXDP diagnostic name keep only the xxxx part
> the MAINDEC #. To run it, do:
> R xxxx??
> The first letter in the diagnostic name tells you what processor it's
> for. If I remember correctly C=11/40, Z=any

B is 11/40; C is 11/45

> There's a document that tells all about it (but I can't remember
where I
> found it at the moment).

That would probably be mine, at
XXDP.ps is the same content, just a different format.

The bits from page 6 to 12 are from V2.4, but the rest is mostly

> The pack images that you're talking about don't have the correct
> diagnostic, but I've found that ZMSDD0 (wow! from memory...can you
> I've used it a bunch?) works OK enough to be able to find bad memory
> you'll know when you hit bad memory. I've also found that having a
> hardcopy terminal is preferable to a CRT when you're getting
> If a diagnostic loads and then gives you a prompt like "DB>", START
is a
> good choice as a response.

Pete						Peter Turnbull
						Network Manager
						University of York
Received on Tue Dec 21 2004 - 13:09:38 GMT

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