By far the closest to a complete project, a fabricated display and control system was a project by Martín Bonadeo, which featured 7 characters
Setup of the installation:
Quote from Martín Bonadeo's website...
A 7 characters split-flap-type device (such as those used in airports and train terminals in the 70) is located at Telefonica Foundation's main entrance. Each of these modules contains 30 characters including the letters of the alphabet and some punctuation. The board has a total size of about 30 cm. x 7 cm. high. All characters are moved every 1 minutes to stay fixed in a new letter. Only the first and last module will not move but remain always in the same positions, the letter "P" and "O" respectively. The rest of the characters is constantly forming the words "publico" (public) or "privado" (private). This sign is shot and this image is projected from one of the windows to the sidewalk of the Plaza Vicente López (next to the fence). This image has a size of 5 meters wide x 1 m high. The characteristic sound of this technology produced by the board is also amplified and "projected" to the plaza.
More on how this works: