TIMER_SEL0
outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH); /* count-down timer */
outb(TIMER_MODE, TIMER_SEL0 | TIMER_SWSTROBE | TIMER_16BIT);
outb(TIMER_MODE, TIMER_SEL0 | TIMER_SWSTROBE | TIMER_16BIT);
outb(TIMER_MODE, TIMER_SEL0 | TIMER_SWSTROBE | TIMER_16BIT);