In the late 1930s, IBM produced the “Radiotype”, a IBM electric typewriter that could be used for radioteletype communications.  IBM supplied many units to the military during WWII.  IBM literature makes it sound like this was the only RTTY system in use during WWII, but of course, there were thousands of M15 in use, also. 

The IBM system had a number of drawbacks.  It was too big and heavy for field use and used a six-level code incompatible with standard teletypewriter equipment. But the military apparently put up with it since the need for communications was so great during the war. IBM had leased the units to the government and took them back after the war.  IBM sold the design to Globe Wireless in late 1945, partly to avoid being in competition with its good customer AT&T, but Globe apparently did nothing with it.  The units may have all been destroyed, since there have not been any reports of them showing up in surplus channels. 





(note Morse keys - for backup?)


The "RadioType" could also interface with the SIGABA encryption machine.  See attached text for a description and how sensitive the machine was to vibrations & movement.

Have fun,

Duncan
K2OEQ