Abstract: A large scale LED display system (12) is provided on a building structure (100). The system has a screen (12) formed of a number of side by side display panels (14) which may be foldable or rollable. Each panel has a number of equally spaced transparent polycarbonate tubes (80) which house pixel units (50) of LEDs (51) connected to printed circuit board (120) and a row controller (121) for controlling luminance of the LEDs. A bus member (54) convey power and video control signals from a panel controller (77) to each row controller. The panel controller has an initialising process adapted to allocate temporary addresses for the tubes and determine screen size accordingly. Video segments are extracted by the row controllers based on the addresses associated with the video control signals from the panel controller.