Abstract: A modular messaging sign panel contains a plurality of LEDs coupled to a plurality of latched drivers. A microcontroller on the panel has a unique serial number permitting the panel to be selectively addressed by a host. The microcontroller receives serial data representing an image frame, selects the data intended for the panel in which it controls and clocks it out to the latched drivers along a single serial data line. Multiple panels can be connected to form a larger display panel system. Each panel has its own uniquely addressed microcontroller. A three wire connection couples the panel or display system to a computer and a power supply. A single jumper wire connects each modular panel together such that the data output from the computer is received by every microcontroller within the system in a parallel configuration.