Equipment are necessary to abide by a protocol so that the interrupt-request (IRQ) strains may be shared. The PCI bus consists of 4 interrupt lines, INTA# by means of INTD#, all of which can be obtained to every gadget. Approximately eight PCI gadgets share the same IRQ line (INTINA# via https://nathanlabsadvisory.com/achieving-fisma-certification-in-the-usa-ensuring-robust-information-security/