[GreenKeys] Identify that ESU

[Henry Minsky]

http://www.beartronics.com:8088/tmp/tty/index.html


These are some pictures of the ESU of a model 28 which I just acquired, without
any documentation.
It looks similar to the one that Charles Ring posted a few days ago.

Can anyone tell me some information about what this thing does? What are
the phone plugs for on the box on the left, and those four screws that 
appear to be
pots labeled PP, BP, RP, TKP ?  And what are those "jones" plugs for?

Just curious ... I am planning to bypass pretty much all that stuff and 
just wire the current
loop directly to the typing unit and keyboard. But if I can use the power 
supply to generate the
loop current that might be nice.


Also -- the type case that came with it looks kind of funny - can anyone 
tell me what
those symbols are for?

Thanks,
         Henry