“Ivan Picelj designed this object after the poster he had created for tendencije 4. It was realized in collaboration with Vladimir Bonačic. According to Picelj, the letters “t4t4t” lit up at the top of the object, one eighth of the object’s area, point after point and from left to right. When the lettering was complete, the lamps went out and the cycle began again.
On the rest of the object’s surface a rapidly changing pattern of lights blinked, which was controlled by a random generator that Bonačic had installed. The object today is not programmed as it was originally; the random generator controlling the lights no longer functions. When the object was restored in the 1980s, the original programming of the lettering “t4t4t” at the top was also changed.”
Source: [Rosen, 2011]