KIM Uno /PiDP-11 plans...

[Ethan Dicks]

On Fri, Oct 23, 2015 at 11:17 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
>     > Alas, it's DPDT, not SPST.
>
> Ooops; the ones in the PDP-11 front panels (/05, /45, /70 and almost
> certainly the /40 too) are SPDT, not SPST

Yes.  The footprint for the existing front panel PCBs are SPDT.

> I looked at the data sheet for the ones you found, and it's actually a sheet
> for the whole series, from which it looks virtually certain that the right
> ones (both pemanent and momentary contact) can be ordered from C+K. It's just
> a matter of working out what the part number would be!

Part number and availability.  From a quick look around, I see low
availability numbers (one part was "3 remaining" and a notice that
they would not be restocking that part).

In the larger scheme, I think it's fine to find these switches for
restoring real machines, but I think we are better off finding
alternate sources for a new design.  The benefit of the "real" panel
mount switches is that if we make a replica PCB with PCB-mount, the
panel mount switches will still work, given the DEC mounting frame
(and that's another kettle of fish - I have one, and I think it's
stainless steel because it's quite "lacy" with 12mm square holes and
1mm of metal between them.  That would be exciting to reproduce in a
home shop).

-ethan