[GreenKeys] TTY protocol

[Jerry Barnish]

Gentleman:
 
I am a ham for 33 yrs and am experienced with tty operations to a point
of being
just a bit past neophyte.
 
What is the meaning of "NNNN" and "ZCZC" at the ending of a message?
I notice the long term users adding it and also on German Meteo msgs
and have not yet taken the time to research it as of yet.
 
I also agree that the fascination of watching the units print has never
become
boring. The public has no appreciation of the history behind the units
and I also agree that it needs to be preserved forever. 
Fortunately, the Battleship New Jersey is giving me the opportunity to
learn
much more about teletype now then I did when I was active on local
VHF nets in the 1980's.
 
Thanks for all of the infornation posted on this net.
 
Jerry WB2CAK