[GreenKeys] Teletype "chat"

[Jim Haynes]

I think most examples will come from ham radio and TTD, since commercial/
military operations didn't approve of operators conversing except in the
line of duty/business.

In ham radio procedures were adopted from Morse code CW operation, using
prosigns like K for "over", KN for "over to the named station only, nobody
break in", and AR and/or SK for ending a contact.  The originators of TDD
were hams, so they started out using the same procedures they used on the
radio.  One difference is that radio requires a definite send/receive 
switch; you can't interrupt the sending operator.  In landline you can 
send a break to interrupt the sender, and in TDD you just start typing and
the sender should stop when he sees a bunch of garbles.

I've also seen GA or GAH  (go ahead) used in a commercial telegraph office
and on TDD.  May be needed on TDD at the start of a connection since the
caller doesn't know the call has been answered, can't hear the end of
ringing tones and the telephone being picked up.

It can be confusing when a phone is used for both TDD and voice.  The
TDD caller calls, a person answers with "hello", the caller might see some
flashing light on his modem, or he might not, so starts hitting keys
to let the answerer hear that a TDD conversation is wanted.  Then the
answerer puts the handset into the acoustic coupler and types GA.

In the midst of a conversation K might or might not be used.  If it starts
off "How are you today?" then you hardly need a K after the question mark.
And in a conversation a pause may be a cue for the other person to start
typing.  But a K could be used to mean "I"m expecting you to say something
now."

If a pause is necessary, as you need to look up something or you are
just thinking about what you are going to say next, it used to be
common practice to hit the LTRS key every second or so, so that the
other station knows the circuit is still up as his teleprinter jumps
on receipt of that character.  Or you could send LTRS-FIGS-LTRS a few
times which makes the machine really jump if it is an old model like
the 15.

R for "roger" or received your transmisson OK.  TU or TNX for "thank you"
or "thanks"  And I've seen MIN PLS meaning "give me a minute, please"

In commercial/military operation it makes a difference if you are on a
person-to-person connection or on a message switching system where your
message just disappears into the system with nobody talking back at you.
On a person-to-person connection, and especially with radio, there are a
whole bunch of Z and Q signals with assigned meanings.  So QSL? meaning
"do you acknowledge receipt of my message?" and QSL meaning "I acknowledge
receipt of your message."  And maybe falling back on plain language
"please repeat the words between 'foo' and 'bar'".

But if you are on a message switching system, or if a message has been
relayed from one station to another, you may have to rely on a "service
message".  Say you receive a telegram with the recipient's name and city
but no street address, or maybe missing an apartment number.  You would
send a message to the originating telegraph office with something like
"SVC YR 24 JULY 13 GBA" meaning "this is a service message. your message 
number 24 on July 13 cannot be delivered give better address"  Then an
operator at the originating office would dig up the file copy of that 
message, see if there is a way to contact the person who sent it and
ask that person for a better address.

Now on a service like Telex or TWX it all depends on whatever rules the
company has.  It might be a large company with a department handling all
message traffic, so an originators message would be handed on paper to
an operator to send, and there would be no conversation between the
sending and receiving operators except maybe to ask about a possible
typing error.  Or to chat about the weather if company discipline is
not tight.  But it might be that the originator of the message wants to
have a personal conversation with the recipient by teleprinter so the
operators are also the conversants.

I once found a piece of TWX copy in Teletype Corp. files (while looking
for something entirely different)  It was about 1944 and the message was
something like

TELETYPE CORP.

THIS IS SIGNAL CORPS.  IS MR ZENNER THERE?

WILL GET HIM

ZENNER HERE

and then a conversation followed about about type bar 
backstops for Model 14 reperforators.  They were originally made of 
leather, and that was not good for use in the tropics, so a synthetic
more fungus-proof material was being substituted.

and finally

TU BYE

BYE

jhhaynes at earthlink dot net