The Commodore-6309 project explores the possibility of replacing the MOS 6510 CPU in a Commodore 64 with a Hitachi 6309. This experimental mod aims to assess the feasibility of running a 6309 in place of the original processor.
STATUS
The prototype runs a test Kernal ROM and executes sample code, including a Mandelbrot set generator. IRQ and VIC-II raster interrupts work, and file loading functions on an NTSC C64 with a 1541 drive. However, PAL systems experience loading failures, and enabling sprites causes issues. Development is based on an NTSC C64 (board revision 250407), though other revisions might work with adjustments.
REQUIRED COMPONENTS
- Commodore 64 (tested on board revision 250407)
- Adapter PCB (or a breadboard with extensive wiring)
- Hitachi 63C09E CPU (external clock variant)
- DS1100Z-50 and DS1100Z-250 delay lines
- GAL16V8 logic chip (tested with GAL16V8D-10)
- Various sockets, headers, capacitors, resistors, and jumpers
- Custom Kernal ROM (e.g., BackBit CornBit flash ROM)
PCB AND SCHEMATICS
The adapter PCB, designed by Gary Becker, is based on his liber809 project for Atari 8-bit computers. The current PCB version (0.8) is for debugging and requires soldering jumpers. The design is available as a shared project on PCBWay.
DISCLAIMER
This project is purely experimental and comes with risks. The C64 used is expendable. Anyone attempting this mod should understand that hardware damage is possible, and warranties will be voided.
Proceed at your own risk.
There’s much much more. Check out the Commodore-6309 Github repository for further detailed information on how you can make your own.
