[GreenKeys] Morkrum M12

[Jim Haynes]

I believe the M12 was always considered a serial machine.  Teletype got
its business because the start-stop serial machines were more practical
for use in the small scale.  The alternative, synchronous operation,
was pretty high-tech for its day and required maintenance people to be
handy; hence was usable mainly between large telegraph offices.  At the
time the electrical distributor was the only way to deserialize the
start-stop signal and then send it into a parallel printer.  It was
quite a breakthrough when Howard Krum devised the original single-magnet
receiving selector.  Company lore says the design was sketched on a
paper napkin while Krum was at Coney Island.  At the time electrical
stuff was considered less reliable than mechanical stuff.  Insulation
deteriorated and broke down; contacts pitted or developed insulating
films preventing closure.  Wires broke from vibration and flexure.

Teletype did have a time-division multiplex in the product line into the
1930s.  This was of no interest to the Bell System, but was sold to
customers such as railroads.  From photographs it is not clear if the
printer used in the multiplex system is the same as the Model 12.
However I received some information from a man in Australia which
included a video of a Model 12 printer running, and I believe he said
it was in a multiplex application.  The later electronic time-division
multiplex belongs to the more modern era of Model 15 and Model 28 and
was sold primarily to the military and other government users.

jhhaynes at earthlink dot net