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BC08H Cables

anders_bzn

Experienced Member
Joined
Jan 27, 2016
Messages
232
Location
Sweden
Hi,

I need a pair of BC08H cables for expanding my pdp-8a omnibus. Are those hard to find? I have drawn a new set of boards that I intend to order if I can't get the real thing. Is there anybody that would be interested if I make some boards?

The boards that I plan to build uses regular flat cable instead of the flexprint cable that I can't find anywhere, just FFC cables which is much thinner and super expensive at long lengths (like 500mm) .

And at last, yes I do have the KK8E processor (otherwise expansion isn't possible).
 

Lou - N2MIY

Veteran Member
Joined
Apr 1, 2008
Messages
1,306
Location
Albuquerque NM / Potomac MD
I'm surprised there had been no responses so far. I would be interested in one set if you made a run of boards. I was looking into such in the past when I wanted to connect a hex-height 8/a 12-slot backplane chassis to my 8/e so that I could neatly install the RL8A.

Lou
 

anders_bzn

Experienced Member
Joined
Jan 27, 2016
Messages
232
Location
Sweden
It's ok. There is one set of boards for each of you.

I have already ordered the boards and I made ten of each (M936/M937). To build one extension set two boards of each are needed. I'll keep at least 2 sets for myself, which means that there is one left.

Those could be used for connecting two back planes together in one PDP-8e box as well, but a little different setup is needed.

I'll upload the documentation later.
 

anders_bzn

Experienced Member
Joined
Jan 27, 2016
Messages
232
Location
Sweden
The boards arrived today, this is what they look like. I have to order the components so I can built the cables. The card edges must be chamfered of manually.

M936-pcb-small.png


M937-pcb-small.png
 

m_thompson

Veteran Member
Joined
Jul 8, 2014
Messages
1,627
Location
Rhode Island, USA
Those boards would plug into the FlipChip tester that a group of us are working on. Each of the signal wires would be connected to a SPI GPIO pin on tester. Using the FTDI drivers and DLLs you could write a program to talk to anything on the end of the cable.
 

anders_bzn

Experienced Member
Joined
Jan 27, 2016
Messages
232
Location
Sweden
Look good to me. Nice silkscreen! Hand-chamfering is a well-honed technology known to many of us :->.

paul
Yes, this is not the first time.

Those boards would plug into the FlipChip tester that a group of us are working on. Each of the signal wires would be connected to a SPI GPIO pin on tester. Using the FTDI drivers and DLLs you could write a program to talk to anything on the end of the cable.
Yes it would be possible. But this is not a project from me, to many other projects. But anyone can download thee gerbers: http://www.pdp-9.net/docs/BC08H/M936-gerber-rev1.zip and http://www.pdp-9.net/docs/BC08H/M937-gerber-rev1.zip

Anders,
I like how you even put holes for mounting handles! The "FLIP CHIP" and M936 and M937 give them the look of authenticity.
Lou

Thanks, I try to do things as good as possible.

I'll order some cables and connectors and some other things that I need to finish the expansion box.
 

anders_bzn

Experienced Member
Joined
Jan 27, 2016
Messages
232
Location
Sweden
Those are really nice. Have you yet "used them in anger" :->?
They just need some rub marks on the fingers, dinged corners, and a few stains for that authentic look!
Interest-level for a set of these remains high, here.

Haven't tested them yet. Don't know why, but I had only bought four PCB-flat cable connectors so I need four more to build the second cable. There is still some small work to do on the expansion box as well.
 

anders_bzn

Experienced Member
Joined
Jan 27, 2016
Messages
232
Location
Sweden
Ok, the cables are tested in together with my homebrewed expansion box. Works OK!

It's built from a PDP-8a/100 chassis with a 10-slot backplane. I had no regulator board for this so it's equipped with modern switch mode power supplies for 5V +15 and -15V (no new holes drilled). I had to build a very simple powergood circuit that holds down the signal in the backplane.

DSC_2205_00001.jpg

I have a couple of boards left, two kits containing four boards (two kits have been promised to Paul and Lou). They are $50 each including shipping worldwide (almost self cost price). Send me a PM if you are interested to bye a set of four boards.
 
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