I've managed to salvage a LED board(4 seperate 8-seg displays on one board with a simple 12 pin connector) from an old microwave hoping to use it in my own application. Apparently, this board has a strange design that is difficult to understand: http://home.comcast.net/~electronicjo/display.gif The two components between the pair of LED displays are normal LEDs. Some things to note: 1.) 5V - Pins 1 through 4(from left to right on PCB connector) are "Display select". When any of these pins are connected to 5V, the corresponding display will light up when the pins from Note 2 are grounded. 2.) GND - Pins 5 through 11 control exactly which LED segment bars will light up. Also note in the diagram that each segment is connected to the next displays' corresponding segment. 3.) Pin 12 of the connector is the common cathode of the two regular LEDs and will only light when Pin 3 is high. Now obviously the problem is this: How can each display have different numeral values if each segment from each display is interconnected? The only solution I can think of is quickly switching each display with a number accordingly so that is appears to have different values. Unfortunately, the main board of the microwave with all the circuitry is damaged, so attempting to analyze that won't work(and also the ICs are antique). Any comments appreciated.