sexy PDP-11/44 panel (was: Re: Original 11/74 front panel)

Don North ak6dn at
Wed Feb 15 00:53:11 CST 2006

Gooijen, Henk wrote:
> Without thinking much about it, I'd say that mounting any
> real blinkenlight console on a 11/44 is *not* trivial!
> Of course, grabbing UNIBUS address- and data-lines and wiring
> that to the lights is trivial, but to get all panel functions
> (LOAD ADDR, DEP, EXAM, etc). working on an 11/44 is more work.
> I guess there are more people on the list who have a boring
> PDP-11/44 with a dull panel, that would like to make the /44
> more sexy with an 'appropriate' panel. The "upgrade" is,
> of course, done in such a way that it can be undone ...
> I (we) do not have a /74 panel :-(  , but I'd like to hear
> what approach you are thinking of, Don.
Well, what I thought about was a simple little dual-width UNIBUS card 
(MUD slot
and 11/44 extended MUD compatible for the extra phys address lines) that 
read-only buffer the UNIBUS address/data/control lines and send them to 
the display
board (either parallel or multiplexed, undecided).

The display board would be run by a PIC micro (I have lots of experience 
with these)
that would intercept the 11/44 console serial port lines and would 
generate all the
appropriate exam/dep/etc commands to mimic the switch commands. The PIC 
also run all the display lites, selecting either real-time UNIBUS A/D 
display, or the
manual results obtained from running commands.

I would use my 11/74 panel for the display bezel (no destructive changes 
of course)
just to provide some extra atmosphere.

There is no ETA on this right now, got other things to do first...
> Hmm, you could do it like I did as add-on to SIMH.  Hardware
> with some intelligence reads the front panel and translates the
> switches to messages in ODT syntax which are send to the 11/44
> monitor program ...
> - Henk, PA8PDP.
>> -----Original Message-----
>> From: cctalk-bounces at 
>> [mailto:cctalk-bounces at] On Behalf Of Don North
>> Sent: vrijdag 10 februari 2006 21:07
>> To: On-Topic and Off-Topic Posts
>> Subject: Re: Original 11/74 front panel
>> Actually I was thinking of making a replacement/alternate 
>> front panel for my 11/44 using the 11/74 panel.
>> Add real blinking lights/switches connected up to the real
>> UNIBUS/memorybus.
>> The 11/44 panel is *way* too spartan looking, and the 11/74 
>> panel would fit just perfectly on the front of the box.

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