Gadgets Are required to follow a protocol so the interrupt-ask for (IRQ) traces is often shared. The PCI bus contains 4 interrupt traces, INTA# via INTD#, all of which are available to each system. As many as eight PCI equipment share exactly the same IRQ line (INTINA# by INTINH#) in https://nathanlabsadvisory.com/ncema-7000-2015-certification/