vIFR
gIFR = vIFR;
via1[vIFR] = 0x7F;
(uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
(uint) via2[vIFR], (uint) via2[vIER]);
events = via1[vIFR] & via1[vIER] & 0x7F;
via1[vIFR] = irq_bit;
via1[vIFR] = irq_bit;
if (count_high > 0 && (via1[vIFR] & VIA_TIMER_1_INT))