Gadgets are necessary to follow a protocol so the interrupt-request (IRQ) strains may be shared. The PCI bus contains 4 interrupt strains, INTA# via INTD#, all of which are offered to every device. Approximately eight PCI products share exactly the same IRQ line (INTINA# as a result of INTINH#) in https://nathanlabsadvisory.com/ciso-service/