case 0xa000:IRQCount&=0xF0FF;IRQCount|=(V&0xF)<<8;break;
case 0xb000:IRQCount&=0x0FFF;IRQCount|=(V&0xF)<<12;break;
case 0xc000:IRQa=V&2;break;
case 0xa000:IRQCount&=0xF0FF;IRQCount|=(V&0xF)<<8;break;
case 0xb000:IRQCount&=0x0FFF;IRQCount|=(V&0xF)<<12;break;
case 0xc000:IRQa=V&2;break;