C=Key Keyboard interface
The C=Key Keyboard interface
View some pictures or download the code and schematic.
The unit is powered by an Atmel ATmega32/162 microcontroller. The code can handle keyboard matrices from 1×1 to 16×8, so the C64 and C128 keyboards can be accomodated. In addition, 2-4 joysticks can be mapped in as “keys” as well. As you can see, the unit doesn’t really require a PCB, but can take advantage of one.
Features include:
1. Multiple key rollover support. The issue of “ghost keys” is still an issue for 3+ keys being held down.
2. Entire 16×8 keyboard matrix scanned 60 times a second
3. Single IC solution (for C64/128 KB to PS2 direction)
4. Key repeat supported for all keys and follows PC keyboard semantics
5. Replacing one source file in the application will allow support for another keyboard style
6. Easy construction
Planned enhancements:
* Programmable keys
* LCD screen support



