[GreenKeys] WTB J.H. Bunnell Pen Register

[John Nagle]

> From: Jim Cooper [jim.w2jc at gmail.com]
> 
>> A picture or description of what they should look like, or what
>> size and how
> See the Wikipedia article  "pen register" --
> https://en.wikipedia.org/wiki/Pen_register
> 
> (I had a hand in making the article actually look back at former uses
> of pen registers outside law enforcement, tracing the technology back
> to Samuel Morse and the terminology back to the 1890s, when pen
> registers were used to do what we now do with oscilloscopes.
> 
> Doug Jones jones at cs.uiowa.edu

    Yes. They're descended from the "Morse inker".

I have one of those. The picture in Wikipedia is of mine.
I built a box with a phone dial and a 9 volt battery so
it can be demoed.

It has a cute mechanical mechanism which starts the
tape on the first pulse, and stops it after about
2 seconds of no activity.

If you need the paper tape for it, you can use 1/2"
tape of the type used for high school physics
experiment timers.

https://www.pasco.com/products/lab-supplies/measurement/me-9284

The ink roller runs well on stamp pad ink.

				John Nagle