[GreenKeys] Early teletype round keyboard.

[John Nagle]

> From: Jim Haynes<jhhaynes at earthlink.net>
> To: Jeffrey D Angus<jdangus at att.net>
> Cc:"greenkeys at mailman.qth.net"  <greenkeys at mailman.qth.net>
> Subject: Re: [GreenKeys] Early teletype round keyboard.
 >
> The keyboard is round because of the way the thing works.  It's called a
> monopulse, was intended for short range communication for such as
> inter-plant.  It was called Model 36, circa 1948.
>
> It works by sending a single pulse of variable length per character.
> The leading edge of the pulse starts a typewheel rotating at the receiver
> and a stop arm rotating at the transmitter, in synchronism because they
> are running off the same 60 Hz power system.  The end of the pulse causes
> a hammer to hit the paper tape at the receiver and print the character
> that is under the wheel at the time.
>
> It's safe to say the item is rare, if only because there was nearly zero
> demand for such a product.

     I've seen that keyboard for sale on eBay a few times. I've
never seen the receiving end for sale, though.  149 units produced,
supposedly.

Pictures:

    http://www.prc68.com/I/Monopulse.shtml

				John Nagle