[GreenKeys] Unshift on space

[Jim Haynes]

On Wed, 6 Nov 2013, Ralph Mowery wrote:
>
> The other item often missed is to send the FIGS J and S together to get the ' 
> or BELL.  Seems alot of machines were set up either way depending on the 
> exact character set used.
>
Yes.  Figs S is the Bell System and U.S. military standard, while Figs J
is the Western Union preference for bell.  And maybe the European 
standard.

The origin of this seems to be that Associated Press wanted two different
bell signals, one to ring the bell on the machine and another to ring a
remote bell in an editor's office.  I assume to let the editor know that
a really hot, stop-the-presses story was on the wire.  Figs S and Figs J
were used for the two signals.  Somehow when that requirement went away
the companies diverged as to which signal should activate the bells in
the machines.