I don’t know about the Times Square one specifically, but at least some of them used paper tape with holes punched in a grid corresponding to each light bulb. The messages would be typed on the paper tape and fed into a reader with a grid of pins. Where there were holes in the tape, the pins would contact a current source and activate a relay to turn on the corresponding light bulb. The paper tape could be connected at the ends in a loop to repeat the same message.
In the late 1960s when I toured a newspaper, they still used punched paper tape for teleprinters and to convert wire news and typewritten articles directly into typeset.
Throughout most of the 70s, I used paper-tape keyboards for typesetting. They were standard QWERTY keyboards with extra keys, like a “bell” key for coding. This continued until the late 70s, with the advent of the floppy disk. Oh, the fun of having someone dump chads over your head, and still finding them weeks later.
As I heard it, back in the chad days it was forbidden to dump chad out a window during a ticker tape parade in NYC. The fear was that it would get into people’s eyes.
It is discussed extensively in “News in Lights: The Times Square Zipper and Newspaper Signs in an Age of Technological Enthusiasm” (Cressman, 2018). The paper includes photographs and diagrams of the mechanism and a history of its development.
It’s not a real thing, but one of the details I love about Fritz Lang’s 1927 film Metropolis is that in Joh Frederson’s palatial office overlooking the city, there are numbers continually scrolling down the wall as young bureaucrats scribble them down. It’s never explained what these are, but, given the setting, it seems likely that they’re stock quotations. It’s the first case I know of anyone depicting an electronic stock ticker, ages before LED displays existed.
I don’t know if lighted stock tickers existed then – it seems too early ( and predate by a year the One Times Square “crawl” that started this thread). But the figures don’t show signs of pixellation. Undoubtedly they did the effect for the film by really just using white numbers on film strips being slowly moved over light panels, but it implies some sort of higher technology that could make smooth-edged numbers (much the way the special effects work in 2001 made the computer displays look ultra-high-resolution, whereas the use of actual computer displays in the film 2010 ironically make that film look like lower tech.)
I was able to view a similar device in the 1970’s that was used to control a sign at the bank building on the corner of Sunset & Vine in Los Angeles. This controller was about the size of a washing machine, and used paper tape, but not punched holes. The tape was pre-printed with a continuous grid pattern, each square representing a light bulb in the external sign. A clerk would fill in the desired squares with a black marker, then insert the completed tape into a reader. The reader pulled the tape past sensors, and the black/white pattern was stored in RAM. When the sign was activated, the RAM data was sent to the outside bulb matrix by a timed and repeating program.
The bank used it for advertisement, and had several stock tapes around so they could switch the message.