The schematic components in this library have been specifically laid out such that chips with similar function and purpose will have compatible/equivalent pins in the same position, and incompatible pins will not overlap. This means it should be easy to replace one similar component with another, with minimal or no re-wiring; it also means that such a replacement should not result in a signal being routed to an incompatible pin by accident.
For example, if you were creating a design with the 6502 part, but then decided to replace it with a 6512 part, the phase 0 and phase 2 pins are in the same location because they have compatible functionality, but the phase 1 pins are not because on the 6512 it is an input, whilst on the 6502 it is an output.
To add this library to your KiCad Project, do the following steps:
1. Copy the source files "65xx.lib" and "65xx.dcm" to the root of your KiCad project's folder.
2. In Eeschema (the schematic editor of KiCad) go to the "Preferences" -> "Manage Symbol Libraries..." menu option.
3. In the Symbol Libraries dialogue that appears, switch to the "Project Specific Libraries" tab.
4. Click "Append Library", beneath the table.
5. In the new line of the table, set Library Path to "$(KIPRJMOD)\65xx.lib" on Windows or "$(KIPRJMOD)/65xx.lib" on Linux/Mac, and ensure Plugin Type is "Legacy".
6. You can leave the Options and Description fields blank. You should set Nickname to something descriptive - for example, "65xx library".
7. All done: you are now ready to use these schematic components in your project!
