[GreenKeys] SB-2244 TTY patch panel

[Brooke Clarke]

Hi:

It may be related to TEMPEST.  A mechanical TTY machine generates RF 
signals at each on or off transition.  If a bunch of machines are 
synchronized so they all have a transition at the same time then their 
TEMPEST emanations may get mixed up.

Have Fun,

Brooke Clarke
http://www.PRC68.com


Jim Haynes wrote:
> Some implementations of Teletype with crypto equipment required that the
> stepping the Teletype keyboard or tape reader at a fixed rate.  In the
> Model 28 parts books you'll see mod kits to adapt things for "synchronous
> pulsed operation".  A large station might have a TD stepper facility
> consisting of a baud rate generator and then a bunch of boxes that
> send out TD stepping pulses to all the TDs.
>
> I don't know why it was this way.  I don't have any first-hand knowledge
> of crypto equipment, but I did once buy some TD stepping equipment at
> a surplus sale.
>
> Where this is done each TD or keyboard has to have its usual loop and
> then a loop for the stepping pulses.  So I'm guessing what you have
> provides for switching both the signal and the stepping pulses.
>
>
>
> jhhaynes at earthlink dot net
>
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