OK, I didn't connect the SystemOne name until you included Wangrow. Unfortunately, Dan Wangrow died of cancer in 2003 and his company died with him. They closed up shop at the end of 2003 and there's no longer any web site or on-line documentation. Wangrow and NCE worked closely together to develop throttles and decoders in the early days of DCC so there's a chance they may have some of the documentation for these early SystemOne decoders.