I did see the schematic the second time I went by the site.
Has anyone used a 6502 in a C64? I guess they had to emulate the P0...4 lines.
The the 6510 has port mapped I/O and the 6502 has memory mapped I/O.
It has been a while since I got into a real C64.
With a C64, what I have read is that $DF0x is the start of where the reu sends and receives data and commands. Making address decode is the hard part I guess.