Equipment are required to adhere to a protocol so the interrupt-ask for (IRQ) strains may be shared. The PCI bus incorporates 4 interrupt traces, INTA# through INTD#, all of which can be found to each system. Up to eight PCI devices share the identical IRQ line (INTINA# by INTINH#) in https://nathanlabsadvisory.com/supply-chain-security/