Pretty good guess!
It's complex for my limited capabilities, but when all is said and done, most of the hardware is stuff I was already building. The initial I/O board was an off the shelf kitset for NZ$50- (US$35-) which was complicated in implimentation but by the time I understood it the larger capacity GP version design was obvious.
Well no, but DCC didn't answer the requirements my layout has. I could have spent large wads of money to have DCC do what I need of it and _perhaps_ I could have got where I am now. DCC is available as one of the cabs (those block controllers are simple amplifiers) but that's only for decodered locos in non-DC mode. Twenty years on since I first looked at Digital/DCC the decoders are finally reaching the standard where they equal/surpass my controllers, but I think the problem of (human) loco address recognition is unsolvable.
Regards, Greg.P.