J‑CPU64 Commodore 64 (C64) MOS 6510 or 8500 Replacement. Exhaustively tested to ensure 100% compatibility with the original MOS 6510/6500 CPU. Direct drop‑in replacement, no soldering required. Incorporates the complete 6510 instruction‑set, including unimplemented op‑codes. Tested with numerous C64 hardware add‑ons and mainboard revisions.