A very sad PDP-8/S

steven at malikoff.com steven at malikoff.com
Sat Nov 3 21:48:29 CDT 2018

Ethan said
>> If there are any special 8/S lightbulb housings that were plastic, I'm happy to CAD them up and 3D print...
> Nope.  That's now how these worked.  The bulbs had "flying leads"
> coming out of the glass, no bases, and the light barrier was a bit of
> MDF with holes in it (the MDF is visible in at least one of Guy's
> photos).  The bulbs just hovered over the PCB and just hung loose in
> the holes in the MDF.

Ah! ok thanks for clearing that up. It makes me wonder if the 11/15 is much the same. I have not got to
looking at it properly, but I am sure it has a similar MDF base for the bulbs.
> Later PDP-8 models used "bi-pin base" bulbs that had a
> factory-molded-on base and a pair of sturdy pins.

Sounds very /360-ish :)
> There were plastic mounts by the early 1970s when DEC switched to
> LEDs.  I've seen them in the PDP-8/M and the PDP-11/70, among other
> machines.  There's a single and a triple shape.

And also, as I have just found out, a 6-LED shape in the 11/05. I had already drawn up the 3-LED mount for the
11/03 (https://www.thingiverse.com/thing:2829191) but until I unscrewed the switch board from an 11/05 console
a few minutes ago, found it actually has three 6-LED mounts and a single. I'll revise that thing shortly.


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