strange number corruption on pdp11/34

[Jacob Ritorto]

    I just found and installed another m9312.  That's the board that houses
the power-on diagnostics, right?
    Assuming that's true, I may have a clue: the machine now halts with
177021 showing when I power it on.  I can still enter 165200 via the front
panel and CNTRL-START it and it then behaves just like before, with the
corrupted numbers.  Does that shed any light?

thx
jake

On Tue, Jan 27, 2015 at 10:00 PM, Jacob Ritorto <jacob.ritorto at gmail.com>
wrote:

> I moved the console down a notch and replaced the (2) 11/34 board with the
> (3) 11/34a boards.  Got a lovely BUS ERROR, couldn't get control of panel
> with CNTRL-HLT.  So I put the original (2) 11/34 boards back in and it's
> running as it was before.   Ho Hum.
>
> On Tue, Jan 27, 2015 at 9:20 PM, Jacob Ritorto <jacob.ritorto at gmail.com>
> wrote:
>
>> Awesome, I'm just going to swap cpu boards and try again, then.  Never
>> hurts to have floating point, I guess (actually, in the pdp11 world, I bet
>> there are cases where it hurts :\ )
>>
>> Thanks Noel!
>>
>> On Tue, Jan 27, 2015 at 9:03 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu>
>> wrote:
>>
>>>     > From: Johnny Billquist
>>>
>>>     > Is noone paying attention to the fact (and my previous comment)
>>> about
>>>     > using 0 for CSR and vector???
>>>
>>> Err, no. :-)
>>>
>>> But seriously, I'm a bit boggled that a diagnostic program would _not_
>>> have
>>> as default the 'standard' vector/address. So I'm kind of assuming that
>>> the
>>> 0's are somehow bug results.
>>>
>>>
>>>     > From: Jacob Ritorto
>>>
>>>     > I grabbed a set of pdp11/34a boards ... Can I plug them straight
>>> into
>>>     > this blackplane that's currently housing my misbehaving 11/34?
>>>
>>> Yes, if the backplane is some flavour of DD11-P (I don't know of any
>>> backplane that supports the 11/34 but not the 11/34A, but I only have
>>> direct
>>> confirmatory documentation on the DD11-P, and it supports both).
>>>
>>> My vague recollection is that one can use _either_ the M7265/M7266 (but
>>> as
>>> paired set) _or_ the M8265/M8266 set, but you can't mix and match them.
>>> But
>>> don't depend on that (I'm too tired to dig into this tonight, I'll do so
>>> tomorrow).
>>>
>>>     > Backplane markings are very faded but seem to say dd11-pk.
>>>
>>> Yeah, that's the 11/34 backplane (actually, the DD11-P part - the -PK is
>>> the
>>> version with the wire harness to work in a BA11-L or BA11-K; the -PF is
>>> for
>>> the BA11-F or BA11-P).
>>>
>>>         Noel
>>>
>>
>>
>