The 100MHz 6502
11 hours ago
- #FPGA
- #RetroComputing
- #6502
- The 6502 CPU was widely used in late 1970s and 80s home computers and game consoles.
- A re-implementation of the 65C02 in an FPGA allows upgrading old systems to 100 MHz.
- The FPGA-based 65F02 uses a CPU core developed by Arlet Ottens, extended by Ed Spittles and David Banks.
- The 65F02 is packaged in a Spartan-6 FPGA with 64 kByte on-chip RAM, matching the 65C02 pinout.
- It acts as a universal accelerator for 6502/65C02-based systems, with support for up to 16 memory maps.
- The 65F02 copies host RAM/ROM content at startup, running at 100 MHz except for I/O addresses.
- Successfully tested in Apple II, Commodore 8032, and Mephisto chess computers.
- Supports Conchess chess computers (except Victoria) and aims to add more models like Fidelity and Novag.
- Potential support for Acorn BBC Micro, Atari 400/800, and Commodore C64 is under consideration.
- Limitations include memory expansion boards, bank switching, and software/hardware incompatibilities.
- An optional hardware switch disables acceleration for compatibility with original speed.
- The project remains a hobby, with no current plans for commercialization.
- FPGA limits prevent adding more memory maps without compromising 100 MHz reliability.
- Future technical options, like dual-boot configurations, are being explored.