RK11-C indicator panel inlays?

Mike Katz bitwiz at 12bitsbest.com
Mon Dec 6 16:45:29 CST 2021

One of my zillions of projects is to redesign Oscar Vermilion's PdDP-8/I 
using the Raspberry Pi Pico board and these LEDs.

I would use one core for SIMH (the PDP-8 simulator) and one core for the 
Incandescent Emulation.

Right now I'm too busy finding parts for my real PDP-8/E and getting it 

Think of the addressable LEDs and LEDs with the shift register built in 😄.

When you are ready for a redesign, you might consider it for a cost 

If I may8 ask a question.  I have never had boards made before. How do I 
find a good board house that is reasonable and how do I specify the 
board especially for the PDP-8 Omnibus which should have gold fingers on 
the edge connectors?

Thanks and good luck,


On 12/6/2021 2:07 PM, David Bridgham via cctalk wrote:
> On 12/6/21 10:36 AM, Mike Katz via cctalk wrote:
>> Each LED requires 24 bits of data.  That would be 3,456 bits.  The
>> WS2812B has a 300uS low start indication and 1.25 uS per bit.  That
>> would mean it would take. 4.62mS to update the all of the LEDs.
> If I'd known about those when I designed my boards, I might well have
> gone that way.  They're surprisingly inexpensive even.
> Instead, I ended up using a 16-LED driver chip that basically looks like
> a shift-register.  I clock in the 144 bits (just on-off, no fancy
> tri-color LEDs I'm afraid), toggle the latch signal, and there it is.
> If you want to support more indicator panels, it's just a longer shift
> register.  I then added RS422 driver chips for noise immunity and there
> I was.
> Dave

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