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BC08H Cables

anders_bzn

Experienced Member
Joined
Jan 27, 2016
Messages
239
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).
 
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
 
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.
 
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
 
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.
 
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.
 
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.
 
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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