DEC M9312 Configs for a 11/40

william degnan billdegnan at
Sun Nov 27 10:22:15 CST 2016

On Sat, Nov 26, 2016 at 5:35 PM, william degnan <billdegnan at>

> 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.  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.

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.  Given I also have
issues initiating RL11 bootstrap (with known working equipment), 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.



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