Not really, IMHO - the C64 is as if made for tinkering; if you want to design hardware to interact with or enhance a computer, the C64 is the place to go; just

Not really, IMHO - the C64 is as if made for tinkering; if you want to design hardware to interact with or enhance a computer, the C64 is the place to go; just about every conceivable signal is easily accessible, a lot of the chips are in sockets, rather than soldered in (thus easily replaceable or, for that matter, simpler to break signals out of). In addition, 6510 assembly is pretty straightforward getting into, so writing your own software to make use of the hardware you just designed and built is not unsurmountable for a hobbyist. Heck, I still play with my C64 on occasion.