[GreenKeys] a model 15 autoanswer drum?

[John Nagle]

> From: "Larry Tighe" <larryradio at att.net>
> To: "Jim Haynes" <jhhaynes at earthlink.net>; <gil at baudot.net>
>>> >> I've seen those.  You'll note the machine is Western Union, and
>>> >> Western Union operated Telex in the U.S.  Answerback has long been
>>> >> a feature of Telex.

   Yes.  If you read back issues of Western Union Technical Review from
the 1940s and 1950s
(http://massis.lcs.mit.edu/archives/technical/western-union-tech-review/)
there's a huge range of specialized WU hardware.  What we still have
around today is mostly the customer-facing hardware.  Within WU, there
were lots of other devices.  Some neat ones I've come across:

- "Desks".  There were various standard WU "desks", with combinations
of perforators, transmitter-distributors, printers, gluing desks,
timestamps, and internal relay boxes.  There were desks for sending
positions, receiving positions, sending-receiving desks for small
offices, admin desks, and test desks.

- The "page printer control unit".  This was a relay box which did
word wrap for Model 15 machines.  Telegrams came in without word
breaks, and the relay box inserted a CR LF after the first space
after 58 characters, or after the 70th character if no space came
along.  It also recognized the start of message indicator and
sent a form feed.  This was used with a pinfeed Model 15 RO filled with
fanfold telegram blanks, so a complete telegram could be printed
automatically.

- Serial number generators and checkers.  A lot of effort was put into
serializing messages to make sure lost messages were detected.
This usually involved stepping switches.

- Many reperforator/reader combos used for store and forward message
switching in Plan 21-A, Plan 51, and Plan 55-A.

				John Nagle