[GreenKeys] Navy abandons M28 compatibility

[John Nagle]

> The U.S. Navy is changing the format of messages to include lower case
> characters.

    Finally!

> "The Navy and other services have a long history with all-caps
> messages. 

    That was originally for backwards compatibility with Morse code.
Morkrum's first machine, the Blue Code machine (1910) had upper
and lower case characters, with three shifts, LOWER, CAPITALS,
and FIGURES, and a 3-row typewheel.  But printing telegraphs
were originally used only on main lines, so the same message
would also go over a Morse link.  Lower case info was lost
in Morse transmission.  Western Union asked for machines
without lower case, and that's how it all started.

				John Nagle