Commodore 64C KiCad schematics

This project contains a series of schematics and PCB designs for the Commodore 64C (aka C64-E) personal computer, redrawn in KiCad.

The schematic was extracted from images available from Bo Zimmerman's FTP site.

The images are also available in the documentation directory.

The project is structured in three main folders:

• 250469-RevA - Revision A of the motherboard. This version is also known as Short Board and sports the 64 pin "Super PLA" (code 251715-01).
• 250469-RevB - Revision B of the motherboard. This version has a more advanced version of the Super PLA (code 252535-01) that integrates the Color RAM.
• docs - Documentation.
• libs - Project's specific KiCad libraries.

References

• Schematics from Zimmers FTP site.
• C64C Service Manual.
• Hardware information from the C64-Wiki.

Differences

While designing the schematics, I decided to consider the availability of all the components used as a top priority. While there's little I can do for many of the ICs, many other components can still be sourced from distributors today.

A few regular components are, however, impossible to find now. In these cases I replaced them with the closest substitute I could find that is widely available. These components are different from the originals:

• CR2: Diode Rectifier Bridge
• L1: Line Filter, 8 terminals
• Y1: Crystal
• L3,L4: RF Choke Coils
• Some transistors and diodes

KiCad libraries

Both subprojects use two KiCad set of libraries:

• The KiCad Retro Library.
• Project-specific libraries located in the libs directory.
  • 250469-01.lib - C64C specific symbols.
  • 250469-01.pretty - C64C specific footprints.

The project-specific libraries are located in a directory above the actual KiCad project. They are referenced through the KIPRJMOD environment variable in this way: "${KIPRJMOD}/../libs/<name of library>".

Credits

This project has been heavily inspired by these awesome projects:

• LittleSixteen - Clone of the Commodore 16 by @SukkoPera.
• Commodore-Plus4 - Clone of the Commodore Plus 4 by @StormTrooper.
• KU-14194HB-RevB-KiCad - Clone of the Commodore 64, Assy KU-14194HB-RevB by @bwack.

Contributing

We gladly accept contributions via GitHub pull requests. Please see CONTRIBUTING.md for more details.

License

Original schematic drawings and service manual are © Commodore Electronics Ltd.

All KiCad design files are copyright © 2020 Andrea Cisternino.

This project is Open Hardware licensed under the CERN-OHL-S v2 license.