Chapter 3

List four activities of a typical operating system.

Suppose three items, R, S, and T, are placed in a queue in that order. Then one item is removed from the queue before a fourth item, $\mathrm{X}$, is placed in the queue. Then one item is removed from the queue, the items $\mathrm{Y}$ and $\mathrm{Z}$ are placed in the queue, and then the queue is emptied by removing one item at a time. List all the items in the order in which they were removed.

What is a real-time operating system?

If you have a PC or smartphone, identify some situations in which you can take advantage of its multitasking capabilities.

On the basis of a computer system with which you are familiar, identify two units of application software and two units of utility software. Then explain why you classified them as you did.

a. What is the role of the user interface of an operating system? b. What is the role of the kernel of an operating system?

What is the use of the process table in program execution?

What is the difference between a process that is ready and a process that is waiting?

What is the difference between virtual memory and main memory?

Suppose a computer contained $512\mathrm{MB}$ (MiB) of main memory, and an operating system needed to create a virtual memory of twice that size using pages of $2\mathrm{KB}$ (KiB). How many pages would be required?