TIMER_SEL0
outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_16BIT;
new_mode = TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT;
new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_LSB;
new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_16BIT;
outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);