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Cable for DZV11 (BC11U-25) or something similar, where to obtain

Scrub

Experienced Member
Joined
Apr 15, 2023
Messages
81
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USA
Is there anyone that makes or sells these cords, its a 40 pin berg to 4 x DB25 RS232. Can't seem to find it anywhere, anyone know where to buy this or is there an alternative. Thanks
 
Another alternative is to find a 70-19964-01 distribution panel that is used for both the M7957 DZV11 and the M3106 DZQ11, and then use a straight through ribbon cable to connect to it. Sometimes they show up on eBay for a reasonable price, for example this one that sold back in February for $15 (plus shipping):

https://www.ebay.com/itm/295525863662?orig_cvip=true

(Note that the 70-19964-01 distribution panel that is used for both the M7957 DZV11 and the M3106 DZQ11 is different than similar looking H3173-A distribution panel that is used for both the M3104 DHV11 and the M3107 DHQ11).

70-19964-01-Front.png
70-19964-01-Back.png
 
Here's a listing for a M7957 DZV11 distribution panel for $100 (plus shipping). That's a bit much. You could always try a lowball best-offer. You never know, they might bite, but probably not...

https://www.ebay.com/itm/133243188664
I could probably have a bunch of PCBs made up for that price, the board doesn't look very complex. $15 is pretty reasonable, this is really not an urgent matter but it would be nice to make use of that m7957 that I have in my pdp-11/23+ eventually. I am just slowly learning how to use the different operating systems right now. I will keep an eye on ebay if one of these goes up again for a reasonable price.
 
I have the one for the DHV11. I have no use for it, but don't know if it could be made to work in your case.
 
my "lowball" offer was ignored, i guess i'll take that as a no. Interestingly enough the same seller has the M7957 board for sale for the same price
 
Judging by the schematics, the berg connector pinout is the same.

So if someone can take measurements of the metal part (this one), I can extract the relevant PCB section from my larger design and add the extra mounting holes to the circuit board, so it becomes a 1:1 functional and nearly identical physical design.

-Alon.
 
Judging by the schematics, the berg connector pinout is the same.

Which schematics, and which connector pinouts are the same?

As far as I understand things, the M7957 DZV11 and the M3106 DZQ11 use the same breakout panel as each other, and the M3104 DHV11 and the M3107 DHQ11 use the same breakout panel as each other, but breakout panels used by the (M7957 DZV11 and the M3106 DZQ11) and the (M3104 DHV11 and the M3107 DHQ11) are not the same, and not compatible.

Those previously posted photos were of the 70-19964-01 distribution panel. I also have a 70-19964-00 version of that distribution panel, which is slightly different in that it has DB25 Pins 5, 8, 15, 17, 22, 24 populated, which are not on the 70-19964-01 version. I haven't tried checking the continuity yet to see exactly how it is wired up.
 
I checked the continuity of the 70-19964-00 bulkhead breakout panel that I have.

The connections match the table in the DZV11 Field Maintenance Print Set.

http://www.bitsavers.org/pdf/dec/qbus/MP-00462_DZV11.pdf
Page 44, Cable Assy BC11U, Wire Table

Code:
70-19964-00 Bulkhead Breakout Panel

       -  A   B   -  P1-2
P1-3   -  C   D   -  P1-20
P1-22  -  E   F   -  P1-25
P1-4   -  H   J   -  P1-5
P1-7   -  K   L   -  P1-8

       -  M   N   -  P2-2
P2-3   -  P   R   -  P2-20
P2-22  -  S   T   -  P2-25
P2-4   -  U   V   -  P2-5
P2-7   -  W   X   -  P2-8

P3-8   -  Y   Z   -  P3-7
P3-5   -  AA  BB  -  P3-4
P3-25  -  CC  DD  -  P3-22
P3-20  -  EE  FF  -  P3-3
P3-2   -  HH  JJ  - 

P4-8   -  KK  LL  -  P4-7
P4-5   -  MM  NN  -  P4-4
P4-25  -  PP  RR  -  P4-22
P4-20  -  SS  TT  -  P4-3
P4-2   -  UU  VV  -

P1, P2, P3, P4 - Pin 1 - Connected to panel metal frame and connector shells
P1, P2, P3, P4 - Pin 7 - Connected to Berg Pins A, K, M, W, Z, JJ, LL, VV
P1, P2, P3, P4 - Pins 6, 11, 12, 15, 17, 24 - Populated but not connected

70-19964-00-Back.jpg
 
Looking at the schematic for the H3173-A distribution panel that is used for both the M3104 DHV11 and the M3107 DHQ11:

DHQ11 Field Maintenance Print Set
http://www.bitsavers.org/pdf/dec/qbus/MP02380_DHQ11_sch_Jul90.pdf
Page 30 of the PDF, Connector Module Assy

It appears that the only conflict with using one of those on a DZV11 is that Berg Pins K, W, Z, and LL are wired to DSR inputs on the H3173-A distribution panel, but on the DZV11 the Berg Pins K, W, Z, and LL are wired to Ground.

So if an H3173-A distribution panel was used with a DZV11, and something connected to the H3173-A distribution panel was driving the DSR inputs, its drivers would have to be able to handle driving its DSR outputs when they were connected to ground. Maybe most RS-232 drivers can probably handle that. And if nothing was connected to the DSR inputs on the H3173-A distribution panel, then it would be a non-issue.
 
So if an H3173-A distribution panel was used with a DZV11, and something connected to the H3173-A distribution panel was driving the DSR inputs, its drivers would have to be able to handle driving its DSR outputs when they were connected to ground. Maybe most RS-232 drivers can probably handle that. And if nothing was connected to the DSR inputs on the H3173-A distribution panel, then it would be a non-issue.

The RS232 standard requires that any pin can be shorted to ground indefinitely.
On any occasion it is an easy modification to convert between the distribution panel designs.
-Alon.
 
OK found it, the document name is EK-LSIFS-SV-005-vol2.pdf, the mechanical measurements are all there.
-Alon.

1685008440226.png
 
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