I noticed in a recent magazine that a real-time virtual radar is for sale ion the market at £500. Apparently it uses mode S and the base station plugs into your PC using a USB port. It looks guite interesting but I'm not sure of the quality of the imaging and, an not sure if it picks up data from all transponder fitted ac (not really familiar with Mode S. I don't want to p1$$ of any mods by stating the manufacturer and model but if you want more info the PM me. (no I don't work for the company!!!)