In redesigning the INDIANA RAILWAY to include LIGHTED signals, on both the mainline and Dispatcher's Board, what kind of detection circuits and hardware have been used. Trying get an idea of a wiring guide and car/engine/caboose[yes, we still have them] hardware needed. Any programs out there? First time into train detection and trying to learn as we go. Would like to use a dedicated OLD CPU for the "brains" of the project and let it run the system. Systems, programs, comments?