Modern Split-flap displays
Back in the day before cheap digital displays, travelers all over the world used to listen and use these wonderful displays. They were especially popular in European train stations and airports. I say listen, because I still gets waves of travel nostalgia every time I hear them updating.
They are called split-flap displays – because they consist of flaps with digits/letters printed on them that rotated until the right digit or letter is displayed.
Sadly, with the advent of cheap digital, flip-discs, and dot-style displays, these old flip-style mechanical displays have mostly disappeared.
However, a few people have tried to re-create these mechanical wonders. With 3D printing, many people have made their own.
Probably the biggest/most authentic recent attempt is VestaBoard. At $2250 for a board, it certainly isn’t the cheapest version out there – but it does sound right.