On 12/15/2018 11:19 PM, Rod G8DGR via cctech wrote:
However I began to think would it be possible to create a close copy of an 8/e
out of modern parts.
Finally the big one – Omnibus and the connectors its made from. A 3D printing
candidate?
I’m going to autopsy a busted connector and see how they are constructed inside.
Yup, this will be a problem. A couple decades ago, there
was a very common technology, press-fit backplanes. You
made a PC board with all the interconnect on it (power +
signals) and pressed-in contact fingers. Then, connector
housings were pressed onto the contacts. I don't know if
anybody still makes these contacts. It would be hugely
expensive to have custom ones made, but if they are still
being made they might not be too bad. I'm not sure
3D-printed housings would be strong enough for this, but
maybe if ABS they would. Of course, there might actually
still be somebody making clones of the DEC connectors. They
used basically the same design for PDP-8, PDP-11, KL10, VAX,
etc. Certainly, there were people cloning them back in the
1980's. Winchester made the official ones for DEC.
Objectives
The basic board set as original. M8300, M8310, M8320 etc.
Same form factor
Plug compatible – but board contents can differ from original
Well, this could all be done with one FPGA, but if you want
to do each PC board separately, a modest CPLD or small FPGA
would certainly do each board's functionality.
Jon
