Possibly completing the circle of knowledge here...Lionel published the TMCC protocols and let anybody make TMCC electronics. This is why Atlas and others are selling TMCC locos. This decision showed remarkable foresight and IMHO has strengthened the industry and the hobby. One practical aspect of this is that you can buy a TMCC board (from Electric Railroad), with or without railsounds, and make nearly any loco run under TMCC. To me, that is amazing.
Don Merz