pdp8/e frontpanel lamps

Vincent Slyngstad vrs at msn.com
Sun Oct 25 21:35:45 CDT 2009

From: "Philipp Hachtmann":
>>> (I have another box with lamps for RK05 etc. They have the part 
>>> number on the box and "OL-1" directly on the lamps.)
>> Now *those* are much rarer, and are the correct ones for the 8/i.
> Are they? Perhaps the PDP-10 uses them in their header panels?

Well, they are rarer at least in my personal experience.  It is of 
course possible that there are thousands out there that I don't 
know about.

If the PDP-10 panels are 54-08458 Peripheral Indicator panels, then 
those use OL-2.  The only thing that I am positive uses the OL-1 
is the 8/i (and presumably the PDP-12?).

>> If I am remembering correctly, they seemed to have the usual 
>> corporate amnesia about obsolete products and referred me to 
>> their US distributor, Wamco.  Wouldn't hurt to ask someone else 
>> within the company, though.
> Hm...  Did you ask there?

I didn't ask at Wamco, and reviewing the correspondence, it is 
possible that they didn't answer my questions because they wanted 
their disti to do it, rather than because they really didn't know.
It ended up not mattering much -- there are other bulbs made by 
Chicago Miniatures that are probably close enough to the original 

>> They should be.  I have some spare OL-2, but would happily trade 
>> a few for OL-1 :-).
> Hm. I have 26 OL-1. And 80+ OL-2... Wouldn't it better to find 
> some lamps?

I suppose I should be happy with the CM7370 for the OL-1, and the 
CM7371 for the OL-2.  Though they are getting hard to find these 
days too.

> I wonder what I used to replace lamps on the pdp8/l - I have completed 
> at least one front panel. Ah, oh, I think I took them from another 8/l 
> that's completely in pieces.
> So if the 8/i uses the OL-1 lamps, the 8/l probably does as well. In 
> that case I would also be very interested to get some more of those.

No, the 8/i uses OL-1, but the 8/L uses OL-2, like the 8/E.
Here's a pointer to my (somewhat dated) page on the subject:


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