PDP8/e programmers consoles

[Doug Ingraham]

On Wed, Mar 21, 2018 at 8:04 PM, Charles Dickman <chd at chdickman.com> wrote:

> On Tue, Mar 20, 2018 at 11:27 AM, Doug Ingraham via cctalk
> > I guess you can be the first!  Best wishes.
>
> Not sure I want to go there...
>

I hear you there.  I built a front panel for a box I have been calling the
FPG-8.  Modeled after the Straight 8 front panel.  I probably have 100
hours into it at the point I stalled out.  Next step is silk screening the
glass face plate.  Electrically the panel works.  Can do a walking 1's
of the LED's  Can sense all the switches.  Now that I have a 3D
printer I am thinking about a redo of the switches.  They are just
toggle switches right now.  If I tilt them down so when on the handle
sticks straight out (~20 degrees) and add a plastic handle cover
resembling the DEC ones it will look really close.

So expect a few hundred man hours in making a PCB front panel for
omnibus with all the bells and whistles.  Sometimes the things that seem
easiest turn out to be difficult.


> If you have ever looked at the DEC part number listing on bitsaver's
> you will be amazed at all the specials that were done. And that was
> what I was really interested in. Did DEC ever make a fancy panel that
> displayed all the registers? The original designer had it in mind
> since he displays a selected register at runtime during TS1 and when
> the processor is stopped since that is TS1.


As far as I know there are only 3 front panel variants made for omnibus.

1) lamp 8/e panel. (found on e f m lab-8 and DECSet 8000)
2) LED 8/e panel.  (almost the same as 1)  (Found on e, f, m, probably
    Lab-8 and possibly on DECSet 8000.)
3) 7 segment LED panel with keypad on 8/a.  (Still only shows one at
     a time.)

Minor variants of these but none that display all registers/states at the
same time.  Yes you could do this but the panel size would probably
have to increase.  I am sure part of the reason they did it the way they
did was to cut costs.  More lamps would have added considerably to
the cost.  And very little additional gain to functionally.  Most of the
"specials" were probably just different screens on front panels with the
underlying hardware unchanged.  That is certainly true of the Lab-8 and
DECSet 8k.

Best wishes!

-- 
Doug Ingraham
PDP-8 SN 1175