Keyboard Upgrade is firmware that was designed for use on homebrew USB keyboard controllers based on Atmel AVR microcontrollers, particularly the ATMEGA series. The firmware allows multiple user-defined key maps to be uploaded to your controller and switched at any time, turning your keyboard into a Dvorak or Colemak or any other layout keyboard in hardware. It currently supports the following keyboards: IBM Model M, IBM Model M Mini, and IBM M4-1. Schematics for the controller hardware are included. Support for new controller designs can be added to the firmware fairly easily by reusing a common set of source code files.
