Equipment are needed to abide by a protocol so the interrupt-ask for (IRQ) strains could be shared. The PCI bus contains 4 interrupt strains, INTA# by way of INTD#, all of which are offered to each machine. Up to 8 PCI equipment share precisely the same IRQ line (INTINA# through https://nathanlabsadvisory.com/iso-iec-19770-1-2017-it-asset-management/