Computer Hardware and Operating System Basics

Questions and Answers

The kernel mode is used by the operating system, but the user mode is used by application software.

To manage the hardware resources of the computer.

User-mode software

It has complete access to hardware. Signup and view all the answers

The operating system is protected by hardware against user modification, but user-mode software is not. Signup and view all the answers

To manage the hardware resources of the computer. Signup and view all the answers

Because the email reader is a user-mode program, but the clock interrupt handler is a kernel-mode program. Signup and view all the answers

The operating system provides a base for application software. Signup and view all the answers

To manage computer hardware and provide a simpler model to user programs Signup and view all the answers

A Linux operating system Signup and view all the answers

UNIX and its variants Signup and view all the answers

The shell or GUI Signup and view all the answers

To manage computer hardware and provide a simpler model to user programs Signup and view all the answers

iOS is derived from macOS Signup and view all the answers

To manage and allocate computer resources Signup and view all the answers

Linux is a clone of UNIX Signup and view all the answers

Study Notes

A modern computer consists of processors, main memory, hard disks or Flash drives, printers, keyboard, mouse, display, network interfaces, and other input/output devices.

The operating system provides a simpler model of the computer to user programs and manages all the resources.
Operating systems are essential because managing all the components and using them optimally is a challenging job.

Smartphones and tablets are just computers in a smaller package with a touch screen, and they all have operating systems.
Apple’s iOS is similar to macOS, which runs on Apple’s desktop and MacBook systems.
Android smartphones and tablets run Linux as the operating system on the bare hardware.

The most popular operating system in the world is UNIX and its variants, including macOS and Linux.

The program that users interact with (shell or GUI) is not part of the operating system, although it uses the operating system to get its work done.
The operating system runs in kernel mode (supervisor mode) and has complete access to all the hardware.
User-mode software runs in a subset of machine instructions and is forbidden to execute instructions that affect control of the machine, determine security boundaries, or do I/O.

Kernel mode: the operating system has complete access to all the hardware and can execute any instruction the machine is capable of executing.
User mode: only a subset of machine instructions is available, and user-mode programs are forbidden to execute instructions that affect control of the machine, determine security boundaries, or do I/O.