KIM Uno /PiDP-11 plans...

[Ethan Dicks]

On Fri, Oct 23, 2015 at 7:49 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
> We have plenty of the original bezels, from which it would be easy to cast molds
> (the same part is used on the 11/45 and 11/70, unlike the rest of the front
> console).

Casting is one option.  Another is CNC out of dense PVC foam.

> The real issue in any front panel recreation is going to be the switches (not
> the plastic toggles, the actual electrical device). Both the /45 and /70 used
> the now-apparently-unobtainium version with the intergral metal plate to hold
> the switch in place in a metal holder plate.

It's probably possible to find small quantities of the right switch,
but not 2 dozen per panel.

> So a recreation front panel is
> going to have to have some new mechanical design, to allow use of standard
> micro-switches - and that's probably going to mean a re-design of the plastic
> toggles, as those attached to side-plates on the original toggle switches.

The pivot and attachment method is "standard" for C&K paddle switches.
You can still get switches with that arrangement, but with a different
mounting method.

> I wonder how big an order of switches would be required before some
> switch-making firm could be convinced to do a run? Maybe whoever made the
> 'back in the day' still has the tooling to do so gathering dust in an old
> room....

Good question... is it 1,000?  5,000?

> To do that is going to require exactly emulating the interface to the CPU,
> which is not going to be entirely trivial. Physically, the signals all come
> over flat ribbon cables to standard Berg connectors, so that won't be hard,
> but I doubt the interface is documented, someone will have to puzzle it out
> by reading prints - and probably looking at a working one with a logic
> analyzer.

It's been done at least twice

6809-based interface (I happen to have 2 of these, so I'm good here)
  http://www.pdp-11.nl/homebrew/cons1170/cons70startpage.html

Blinkenbone.
  http://retrocmp.com/projects/pdp-11-70-panel-on-blinkenbone
  http://retrocmp.com/projects/blinkenbone (more than just 11/70)

> Also, powering the front console requires an unusual AMP connector shell,
> although that may still be available? And of course one could always bodge
> the power connection...

That's a "standard" shell as used in several DEC power supplies and
for 20mA TTY connections.  They get brought up on the list from time
to time.  I happen to have a basket of them, but they are somewhat
rare on the open market.

-ethan