TIMER_INTTC
if (i8253_channel[2].mode == TIMER_INTTC) {
if (ctr->mode != TIMER_INTTC) {
i8253_channel[0].mode = TIMER_INTTC;
i8253_channel[1].mode = TIMER_INTTC;
i8253_channel[2].mode = TIMER_INTTC;