Gadgets are needed to observe a protocol so the interrupt-ask for (IRQ) lines can be shared. The PCI bus features four interrupt strains, INTA# by way of INTD#, all of which are available to each unit. Around eight PCI products share a similar IRQ line (INTINA# through INTINH#) in APIC-enabled https://nathanlabsadvisory.com/vapt-services/