I just got a 1902 monitor from ebay. I want to hook it up to my C128 for 80 column display. On the back, is the RGB input, and a switch that says "positive-negative". My question is where does the switch need to be? Also, where to get a cable? I read on here somewhere about people using 9-pin serial cables for this connection. Is this possible? Seems strange. Should this monitor work OK with the 128 using this connection? Thanks, in advance, for your help.