The Model 12 was the first practical 5-bit printer and almost 12,000 units were produced between 1922-1943. the M12 was originally designed by the Morkrum Company. In 1924, they merged with the Kleinschmidt Electric Co. to become the Morkrum-Kleinschmidt Corp. That name was felt to be too unwieldy and in about 1928, the company name was changed to the Teletype Corporation. (Morkrum had been previously using the name "Teletype" as  a model name.)

The printer was originally designed to be used in multiplexed systems where the printer signal line consisted of five wires, each connected to an individual selector magnet (one for each bit). So it was a parallel-input printer.  The printer was popular with newspapers to receive news from multiple sources.





Doug beat me to it with more pictures, so I'll refer to his at https://photos.app.goo.gl/8zVHnSHYYbe16jAa9

Note that the keyboard is a separate plug-in module with its own motor. It was an add-on to allow operation in a serial Start-Stop system, which was developed in the early 1920s. If you are familiar with the M15, you will recognize the cam-driven, goose-neck levers on the right, that generate the serial data from the keyboard.  There is another set of goose-neck levers in the middle. These are a serial-to-parallel distributor to drive the five selector magnets.

Gerry already offered his unit to me for the AWA Museum, but we already have one.  Hopefully someone can take this historic unit and save it.  There are probably only a dozen or so of these units still around.

have fun,

Duncan Brown, K2OEQ
USASA    31J30

Antique Wireless Association
 Communication Technologies Museum
   Asst. Curator, Commercial Equipment
(also chief TTY op & repairman)

i-Telex: 212503

www.antiquewireless.org