Gadgets are necessary to follow a protocol so that the interrupt-request (IRQ) traces is usually shared. The PCI bus involves 4 interrupt lines, INTA# as a result of INTD#, all of which can be found to each machine. Around eight PCI products share exactly the same IRQ line (INTINA# by https://nathanlabsadvisory.com/how-nist-800-171-compliance-consulting-in-usa-can-secure-your-business-data/