PUTBYTE
PUTBYTE(0x338, 0x84); /* Red led(GP17), fan on(GP12) */
PUTBYTE(0x370, 0x87); /* Enter the extended function mode */
PUTBYTE(0x370, 0x87); /* (need to write the magic twice) */
PUTBYTE(0x370, 0x07); /* Select Logical Device Number reg */
PUTBYTE(0x371, 0x07); /* Select Logical Device 7 (GPIO) */
PUTBYTE(0x370, 0xe6); /* Select GP16 Control Reg */
PUTBYTE(0x371, 0x00); /* Make GP16 an output */
PUTBYTE(0x338, 0xc4); /* RESET(GP16), red led, fan on */
PUTBYTE(accm >> 24); \
PUTBYTE((accm | (0xff << (bitno-8))) >> 24);