ISR0_IMR0_REG
status0 = read_byte(nec_priv, ISR0_IMR0_REG);
write_byte(nec_priv, IFC_INTERRUPT_ENABLE_BIT | ATN_INTERRUPT_ENABLE_BIT, ISR0_IMR0_REG);
write_byte(nec_priv, 0, ISR0_IMR0_REG);
write_byte(nec_priv, 0, ISR0_IMR0_REG);