It is a credit to the power of the Atmel AVR core which contains lots of fore-thought to achieve a C friendly, 8-bit core with lots of peripherals that can run separately.
Basically it is an overclocked AVR microcontroller with an R2R ladder.
There is a lot more info at
www.avrfreaks.netThe only issue in building one is sourcing that particular AVR as it is pretty new and in short supply.
