[GreenKeys] Nems-Clarke Teletypewriter Switching Unit

[Jim Haynes]

I may be wrong about this without going into the archives for exact
identification, but...

In Model 15 days, CAA/FAA facilities had a 6x6 pushbutton box that
allowed any of up to 6 machines to be connected to any of up to 6
loops.  Similar to Signal Corps SB-66/GG.

Anything that involved recognition of character sequences used a
separate machine called SOTUS.

With the coming of Model 28 the functions of SOTUS were incorporated
into the stunt boxes.  Thus to switch a printer from one circuit to
another, such as a spare machine, it was necessary to switch a whole
lot of other stuff besides the printer loop.  So they came up with a
rack mount panel that used relays to switch all that stuff.  A station
would have as many of those panels as needed for all the printers,
installed in a rack.  The panel in the picture may be one of these,
or a version of one of these.

Another part of this was that the 28s could do selective calling, which
is to say suppressing print of messages not intended for the station.
But for machines that copied everything, such as weather traffic, it
was necessary to switch off the selective calling if one machine was
to serve as a spare for all the applications.  So there was a toggle
switch labelled "LOCAL-REMOTE" on the printer cabinet that operated
a solenoid that disabled the selective calling mechanism.

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 	"Ya can argue all ya wanna, but it's dif'rent than it was."
 	"No it ain't! No it ain't!  But ya gotta know the territory."
 		Meredith Willson, The Music Man