Fuse
low 0xEF, high 0xC9

- external high speed crystal (24 MHz)

ATmega8
-------
low = 0xEF (default 0xE1):
  B7 brown out detector trigger level (def 1)
  B6 brown out detector (def 1=disabled)
  B5,B4 select start-up time (def 10)
  B3..B0 select clock source (def 0001=RC 1 MHz , 1111=fast xtal)

high = 0xC9 (default 0xD9):
  B7 select PC6/RESET (def 1=RESET, 0=PC6)
  B6 WDT always on (def 1=WDT enabled by WDTCR, 0=WDT always on)
  B5 enable SPI (def 0=SPI enabled)
  B4 select oscilator (def 1=slow Xtal, 0=fast Xtal)
  B3 preserve EEPROM by chip erase (def 1=not preserved, 0=preserved)
  B2,B1 boot size (def 00=2 KB)
  B0 select reset vector (def 1=addr. 0, 0=start of boot loader)
