Cheap board guy

Mark G. Thomas Mark at
Fri Aug 21 13:13:33 CDT 2015


On Fri, Aug 21, 2015 at 11:54:52AM -0400, Noel Chiappa wrote:
>     > From: Ethan Dicks
>     > That looks like a great haul.
> We're talking about the guy on eBay whom I posted a pointer to a couple of
> days back, the one with large lots of QBUS CPUs, memory, DLV11s, etc?
>     > I hope they are working cards.
> All the ones I've gotten from the guy above which I was able to test (couldn't
> test, e.g. the RK05 cards 'cause I don't have a working RK05 yet) were OK -
> QBUS memory, 11/23's, etc.

I picked up a bunch of the boards too. My results have been mixed, but
for the price and description, I expected some wouldn't work.

1x M8028 - DLV11-F SLU works.
1x Plessey 32kW memory, works.
2x M8186-YA - KDF11-AA, works.
4x M8192 - KDJ11 (AA or AB?) -- two work, two fail POST, with LEDs lit.
4x MMS1132-N3-128 Motorola 128kW memory - undetermined if works.
1x MMS1102-34 Motorola 32kW memory - undetermined if works.

I haven't figured out the jumpers on the Motorola memory boards yet.
As provided, if I plug one in with the KDF11-AA, I fail to even get 
an ODT prompt.

I picked up a chassis with bridged 2x8 and 2x12 Qbus backplanes in it
at a hamfest (with a good KDF11-AA and 4xM8044s), so my goal is to 
make a pair of small working 11/23 or 11/73 systems. So far, I've got
PDP11GUI successfully running memory tests using microODT via the SLU and 
a Windows PC, enough to test out the hardware as per above.

1) I was hoping I could boot XXDP or RT11 from an RX33/RQDX3. The RX33/RQDX3
works in my 11/53, but so far I'm not having much luck with the KDF11 above.
I picked up a M9058 RQDX3 signal distribution board on e-bay from seller efi
(he has one more listed). It's only got one jumper on it, labelled RX50,
which I have in the non-RX50 position. Since none of this has a bootstrap,
I run the bootstrap from ROM provided by a Dilog SCSI card here, but typing 
"DU" or "DU0" at the * prompt spins the floppy ever-so-briefly, then kicks 
out an error about no boot media found. Suggestions? Maybe I should try
other bootstrap?

2) I could use PDP11GUI, or other tools to load XXDP via the SLU. If anyone 
has already done this and wants to talk to me about it, I welcome some help.

I'm a little confused about what should work and what should not work, with
just the 18 bit qbus. Do I need to wire wrap the additional address lines
to be able to do anything with these KDJ11 CPUs? Does anyone have good
instructions for this modification -- I'll probably want to do it. Do I just
add the additional address lines, or are there other considerations?


Mark G. Thomas (Mark at, KC3DRE

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