The LUFA version is 100807, as in the hardware-pinoccio repository. This version is required for both DFU and USB serial firmware. The arduino-usbdfu directory contains the DFU bootloader on the 16U2 ...

Check that the board enumerates as either "Arduino Uno" or "Arduino Mega 2560". Test by uploading a new Arduino sketch from the Arduino IDE.

April Fools’ Day may have passed, but we really had to check the calendar on this hack. [Damian Peckett] has implemented an Apple ][, its 6502 processor, and a cassette port, all on an Arduino Uno. If ...