EVO64
Returning to the Commodore 64, with a new motherboard and a lot of accumulated affection for the original.
Co-developer · brand, docs & community
- every SID & VIC
- Chips supported
- concept → shipped
- Lifecycle
- 24/7 · GPT-4o
- Support bot
The C64 got me into computing at fourteen. Decades later, I found myself helping bring a new version of its motherboard into the world.
Back to the breadbox
A knee condition had put me out of competitive sports when my parents bought me a C64. BASIC led to 6502 assembly, games, demoscene experiments, and friendships on bulletin boards.
In my forties I found the hardware community rebuilding those same machines. That's where I met Dr. Stefano, of Auroscience. We kept seeing faithful reproductions followed by a stack of add-on boards. We wanted to bring those improvements together on one board.
Who built what
Dr. Stefano conceived, engineered, and laid out the PCB. I worked on product ideas, the brand, website, documentation, and builder community. It took more than six prototype rounds to reach the finished board.
I also wrote a Multi-SID address tester in 6502 assembly. It was my first assembly program since 1992. Some things come back surprisingly quickly.
What's on the board
EVO64 combines modern surface-mount construction with support for original MOS chips. It supports dual SIDs, mono or stereo output, ClearVideo64 composite and S-Video, switchable PAL/NTSC, and the various VIC-II revisions.
A Multi-ROM EPROM holds up to eight kernals. There is a custom CPLD-based PLA, called QAPLA', and optional vacuum-tube or Korg Nutube audio preamps. The aim was to integrate the modifications people were already making while preserving compatibility.
The manuals became an AI project
As the builder community grew, I made a Discord assistant to answer hardware questions from the documentation I'd written. It uses GPT-4o with Pinecone retrieval and stays focused on EVO64 support.
That was one of my first useful LLM projects. It led directly to the larger assistants elsewhere in this collection. I've since stepped back from EVO64 because of work and family commitments, but I'm glad I got to contribute to the community that got me started.
A closer look
On the parts list