Abstract: A multilayer printed circuit board having a pad pattern formed on each of the layers. When the board is assembled, the layers are releasably secured together. The pads on each layer are aligned and make electrical contact with the pads on adjacent layers to provide interlayer electrical connections.

Abstract: A retail store having a computer, point-of-sale terminals, and product code readers at the point-of-sale terminals, includes an electronic price display system. The display system has plural display units, with one display unit at each of the locations in the store where items are held for sale. The computer controls both the prices which are displayed by the display units and the prices which are charged to customers at the point-of-sale terminals. The display units are connected in electrical series by a data transmission line, and price information is transmitted by the computer over the transmission line to the display system in the same order as the display units are connected.