Introduction to Operating Systems

A program that acts as an intermediary between a user of a computer and the hardware is:

Correct: Operating system.

List the four main components of a computer system.

Hardware (CPU, memory, I/O), operating system (controls and coordinates hardware use), application programs (solve the users’ problems with the resources), and users (people, machines, other computers).

When the OS decides between conflicting requests for CPU, memory and I/O, it acts as a:

Correct: Resource allocator.

Which is a software-generated interrupt?

Correct: Trap.

The only large storage media that the CPU can access directly is:

Correct: Main memory.

Compared with magnetic disks, SSDs are:

Correct: Faster and nonvolatile.

Caching is important in OS design to:

Correct: Minimize access time.

______ moves large amounts of data between I/O devices and main memory without the CPU.

Correct: DMA.

Multiprocessor systems’ advantage is:

Correct: All of the above.

Which indicates a symmetric multiprocessing system?

Correct: Each processor performs all tasks in the OS.

What is the difference between multiprogramming and time-sharing?

Multiprogramming organizes jobs so the CPU always has one to execute: when a job waits (e.g. for I/O) the OS switches to another, increasing CPU utilization. Time-sharing extends this by switching so frequently that users can interact with each program while it runs (interactive computing, short response time).

Privileged instructions can be executed in user mode.

False. They trap to the OS if attempted in user mode.

A ____ prevents a user program from never returning control to the OS.

Correct: Timer.