Subject: Front Panel Variations on PDP8's

From: [email-masked] (Stephen Quigg)
Date: Sun, 13 Feb 1994 21:56:27 GMT

I'd like to start another thread, FRONT PANEL VARIATIONS ON PDP8's. For 
instance, the 8e has at least 2 (not counting the MARS panel), depending
on whether it has an 11 or 12 position switch. I never even noticed this until
I tried swapping escutcheons and found that the switch didn't match the 
markings on the panel. I prefer the 11 position panel (I think it's the older
of the two) because it has vertical lines grouping the lamps into groups of
3 to make life easier. I notice on the cover of one of the pdp8a small 
computer handbooks (1975?) a picture of an 8a programmers console. This is
the only picture I've seen where the keypad has round buttons (instead of 
oval); also the layout of the lamps is a little different. Has anyone seen 
this panel?

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From: [email-masked] (Douglas W. Jones,201H MLH,3193350740,3193382879)
Date: 16 Feb 1994 17:25:32 GMT

>From article <[email-masked]>, by [email-masked] (Stephen Quigg):
> 
> on whether it has an 11 or 12 position switch.

I assume you're referring to the rotary switch.  The distinction shows up
on page 4-2 of DEC's 1973 Introduction to Programming, where the artwork
shows the version without the vertical lines, while the photo shows the
vertical lines.  You can also (just barely) tell that the switch in the
photo has a slightly wider angular separation between the lines pointing
to switch positions than the drawing.

There's also the completely different front panel artwork for the
Industrial -8.  This is a PDP-8/E with a red and blue color scheme
instead of the usual mustard and terracotta.  My only PDP-8/E is this
kind, and in addition to additional variations in the line work on the
front, they painted the back of the plexiglass with a transparent red wash
in order to make the incandescent lamps look like LEDs.

					Doug Jones
					[email-masked]