In general the computer responds to an interrupt by storing

the information about the current state of the running

program; storing information to identify the source of the

interrupt; and invoking a first-level interrupt handler.

This is usually a kernel level privileged process that can

discover the precise cause of the interrupt (e.g. if several

devices share one interrupt) and what must be done to keep

operating system tables (such as the process table) updated.

This first-level handler may then call another handler,

e.g. one associated with the particular device which generated

the interrupt.