my system halted! why?

#include <unistd.h>
#define extern static
#include <asm/io.h>

int main()
{
unsigned char ch, i, j;

ioperm(0x70, 2, 1);

for(i = 0; i < 16; i++)
{
printf(\"%4d: \", i * 8);
for(j = 0; j < 8; j++)
{
outb(0x70, i * 8 + j);
ch = inb(0x71);
printf(\"%2d \", ch);
}

printf(\"\\n\");
}

return 0;
}

#undef extern

i want to read cmos data, so i write this program. then i run it  under redhat 8.0\'s kde. when i press enter key, the system is halted. nothing happend!  i press reset button to reset system...

who can tell me why? thanks!
 :(

几点参考：
1）CMOS的可读数据寄存器应该只有12个（可参考MOTOROLA146818 DATASHEET）
2）你的关键错误在于把OUTB理解错了， 应该改为
   outb(i * 8 + j, 0x70)

我在REDHAT 6。2上测试过， 应该没有问题
 :D

i see!
thank you.

?? 146818 has y2k bug
so i don\'t think it can used in new mainboard...

This chip is not used , it is a history. but you can refer to it to get the registers informations :D