DEC M9312 Configs for a 11/40

Josh Dersch derschjo at
Sun Nov 27 11:53:42 CST 2016

On 11/27/16 8:22 AM, william degnan wrote:

> On Sat, Nov 26, 2016 at 5:35 PM, william degnan <billdegnan at>
> wrote:
>> On Nov 26, 2016 2:16 PM, "Josh Dersch" <derschjo at> wrote:
>>> I'll note that the W8 setting described on page A-2 seems to conflict
>> with
>>> the description earlier in the manual (See section 2.8.3) which indicates
>>> it's only necessary for it to be IN if there is an address conflict
>> (which
>>> is probably not the case).  Leave W8 OUT.  (Leaving W8 in will disable
>> the
>>> console PROM).  Sorry for the confusion...
>> Thanks...I will leave out.  The manual could be clearer.
>> Bill
> Follow up -
> I don't think I have issues with my M9312, thanks for your help.   There
> are a number of candidate issues with my 11/40 which are causing my system
> to not be able to initiate a bootstrap of the TU58 ROM using the M9312, or
> bootstrap manually by using the front panel.
> There is at least partial communication between the TU58 emulator (running
> on Comm port 3) of my PC, the M7856's jumpers *I think* are correct to
> serve as the serial card on the PDP 11/40 end.
So you've verified that the vectors on both your SLUs are correctly set?

> I have the LTC turned off.
> There is always more testing I can do, but I suspect my issues are not with
> the serial card.  Taken holistically, I think there is a DMA UNIBUS issue
> somewhere.  Just a hunch.
Can you elaborate on why you suspect this is the case?  Can you describe 
your system in detail?

> If anyone knows of or would be willing to make an XXDP TAP image compatible
> with a 16K PDP 11 I can convert to download via PDPGUI.
PDP11GUI doesn't use TAP files.  You can use PDP11GUI to load individual 
XXDP diagnostics into the PDP-11 without needing to boot XXDP at all.  
Jörg has provided a wonderful database of diagnostics here: Find the 
device you need to test and grab the diagnostic binaries, listings, and 
documentation and go to town.  (See section 5 of 
to see how that's done.)

>   Given I also have
> issues initiating RL11 bootstrap (with known working equipment),
What issues are you having?  Does it hang?  Halt?  How are you 
bootstrapping?  I assume you know the RL11 and the RL02 and the pack 
involved are all known-working?

- Josh

> I have to
> think I should focus on XXDP and somehow get it running using the means I
> know that works, a direct CONSOLE download into core RAM, like I do with
> BASIC.  I have BASIC running in core at the moment, at least there's that.
> Best
> Bill

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