test.c

#include <sys/io.h>

#define FIFO 0x3f5

int main() {
        int i;
        iopl(3);

        outb(0x0a,0x3f5); /* READ ID */
        for (i=0;i<10000000;i++)
                outb(0x42,0x3f5); /* push */
}