Equipment are required to stick to a protocol so that the interrupt-request (IRQ) strains could be shared. The PCI bus involves 4 interrupt strains, INTA# by means of INTD#, all of which can be obtained to every device. Nearly eight PCI gadgets share the exact same IRQ line (INTINA# via https://nathanlabsadvisory.com/nydfs-cybersecurity-risk-assessment/