Powerful Cyclone II FPGA. 128Kbyte battery backed memory. It write save data to SD. Max II CPLD to handle FPGA reconfiguration, BIOS and SD interfaces. 1Mbyte flash BIOS. Voltage shift buffers on PPU and CPU bus for matching levels between 5V bus and 3.3V bus. Far better than simple resistor buffers at reducing noise and power consumption.