There is no documentation on these model signs anymore. The company closed in '94. I do know that this was a DOS based program and this model had a remote type keyboard (which I have but it too is broken, it doesnt want to communicate anymore). I was hoping to remove the control board, just use the LED array, and replace it with the ARDUINO as the driver processor. Bob has one that works but his is a totally different set up with 7 drivers where this one is a 15. He used a UNO, 7) TIP120 to drive the LEDs and a 4017 decade counter to clock them in. Can the Mega with the aid of 15 TIP120's, no decade counter, be used. By connecting a output from the Mega digital to the collector, the #row to the emitter, and +5row power to the base drive enough to make a program scroll a simple message. Or does this have to be a PWM only.