Abstract: A system for electronically displaying item data available in updatable form from a computer, such as item prices, for purchaser viewing. The system provides an infrared encoded signal containing item data applicable to an item on a shelf associated with an electronic display unit. The electronic display unit receives, decodes and displays the data relating to the item. The display units include a display for displaying the data; a photovoltaic cell for providing all necessary power without need for any other external or internal power source; a controller; and a non-volatile, semiconductor memory powered by the photovoltaic cell for retaining the data even in the absence of light energy being applied to the photovoltaic cell. Upon receiving the encoded signal, the display unit determines that the infrared encoded signal is intended for it, and if so, it prepares and displays the data.