The 6526 is infrastructure--it's a timer, clock, and I/O chip and doesn't really have anything to do with the interactive look and feel of the system. So an FP

The 6526 is infrastructure--it's a timer, clock, and I/O chip and doesn't really have anything to do with the interactive look and feel of the system. So an FPGA here doesn't harm the C64's soul one bit, if it works exactly like the original. Honestly it would have been cool if they added a battery and maybe an extra register to indicate its presence; having the TOD clocks keep their time between power cycles would be cool. Edit: If replacing a dead 6526 I would keep the dead one too. :)