Problem:

(a) Modern operating systems are interrupt driven. If there are no processes to execute, no I/O devices to service, and no users to whom to respond, an operating system will sit quietly, waiting for an interrupt or a trap.

What is the difference between an interrupt and a trap?

(b) What is the role of interrupt service routines and how are they related to the interrupt vector?

(c) Figure shows an interrupt time line for a single process doing output. Explain how this operation is being performed.

(d) The figure (a) and figure (b) show two different ways to deal with I/O (Input or Output) requests. When a user process is requesting I/O, two courses of action are possible, synchronous I/O or asynchronous I/O. Describe each flow of action using the figures below, in the context of I/O interrupts.