stock tickers

David Griffith wrote: ..tres cool. Going from their history pages, South America might be a better bet for an original: ".. It has also been reported that during World War II many of the Universal and self-winding tickers were scrapped for metal or sold off to businesses in South America." ".. In 1960, Western Union ordered all these remaining tickers destroyed" Does anybody know what the signalling technique (protocol) for these devices was? I've always been curious about this but never had a mechanism to peruse. My recollection from readings is that async bit-serial devices (tty, baudot codes & c.) ("automated telegraphy") were not really successful until into the 20th century, while these stock ticker networks were functioning decades before that. Looking at the photo gallery on the site and the apparent simplicity of the mechanism, I'm guessing it was just a series of pulses to increment/rotate the print wheel to select the character, followed by a pulse for a print hammer and to advance the tape. There would then be the question of whether it was separate circuits for the increment and print solenoids or whether there was some mechanism perhaps to separate an increment command from a print command sent over one circuit (such as shorter vs longer pulses). Technically, the other half of the system (sending/encoding equipment) would be just as interesting, but like some early fax equipment I have, where there was a similar one-to-many relationship, only a few of the many survive and next-to-none, if any, of the 'ones' have survived.