Chapter 2: Operating Systems Key Concepts

OPERATING SYSTEM

A system software that allows users or the application programs they are using to interact with the computer hardware in an easy and convenient manner

OPERATING SYSTEM

• Make the computer easy and convenient to use.

• Manage the resources of the resources of the computer to make them more efficient

• Execute and control programs

KEY SERVICES

1. Program Execution

2. Access to I/O Devices

3. File System Management

4. System Access

5. Error Handling

6. Communication

Program Execution

It controls program execution for proper access to main memory and I/O devices. The operating system takes care of the memory allocation and CPU scheduling.

Access to I/O Devices

All I/O operations must first pass through the operating system to ensure the proper and efficient use of I/O devices.

File System Management

It refers to file creation, deletion, editing, archiving, remaining, and storing.

System Access

This is done by implementing a log-in mechanism such as user account name and the corresponding password. In this way, improper and malicious use of resources can be prevented

Error Handling

Detects hardware-oriented and software-oriented errors within the computer system and takes proper actions to resolve them.

Communication

There are situations wherein a computer is several running programs at the share time while communicating with one another because they share data.

OPERATING SYSTEM COMPONENTS

It consists of KERNEL and SHELL.

KERNEL, SHELL

It is the OPERATING SYSTEM COMPONENTS.

KERNEL

Heart and soul of the Operating System

KERNEL

Directly controls the computer hardware and performs the services of the Operating System

KERNEL

Hides the hardware details from the user and application programs

KERNEL

Makes appropriate system calls or requests to communicate with the hardware resources

TYPES OF KERNEL

• Monolithic Kernel

• Microkernel

Monolithic Kernel

Fast but less fault isolation

Microkernel

Runs essential services

Monolithic Kernel

An example of this is the LINUX.

Microkernel

It runs essential services.

SHELL

Also called Command Interpreter, as it serves as the interface between the users and the kernel

Command Interpreter

Other name for SHELL

TYPES OF SHELL

• Command-Line Interface (CLI)

• Graphical User Interface

Command-Line Interface (CLI)

requires to type the commands at a prompt, such as the DOS and Linux systems

COMMON MICROSOFT COMMANDS

• File Management

• Network Commands

• System Information and Management

File Management

• dir - list of files and subdirectories

• cd - moves to a different folder

• mkdir - makes a new folder

• del - permanently removes one or more files

• ren - changes the name of the file

dir

list of files and subdirectories

cd

moves to a different folder

mkdir

makes a new folder

del

permanently removes one or more files

ren

changes the name of the file

Network Commands

• ipconfig - displays the computer’s current network configuration

• ping - tests the connectivity to a specified network

• tracert - traces the path of data packets to reach destination

• netstat - displays active network connections

ipconfig

displays the computer’s current network configuration

ping

tests the connectivity to a specified network

tracert

traces the path of data packets to reach destination

netstat

displays active network connections

System Information and Management

• systeminfo - displays the overview of the operating system, hardware, and configuration

• chkdsk - checks a disk drive for errors with attempts to repair sfc /

• scannow - for scanning and repairing corrupted system files

• shutdown - for shutdown or restart

systeminfo

displays the overview of the operating system, hardware, and configuration

chkdsk

checks a disk drive for errors with attempts to repair

sfc / scannow

for scanning and repairing corrupted system files

shutdown

for shutdown or restart

Graphical User Interface

requires user to enter commands by either using drop-down menus or by clicking on icons using a mouse painter

OPERATING SYSTEM SERVICES

• Process Manager

• Memory Manager

• File Manager

• I/O Manager

PROCESS MANAGER

Also known as Process Scheduler or CPU Scheduler

Process Scheduler or CPU Scheduler

The PROCESS MANAGER is also known as

PROCESS MANAGER

Responsible for determining which among these programs will execute first

MEMORY MANAGER

Handles the memory allocation and monitor which memory areas are in use or free

MEMORY MANAGER

Provides protection mechanism for the memory management

FILE MANAGER

Organizes and presents for easy access by the file manager.
Prevents unauthorized file access.

I/O MANAGER

Grants user requests to use the I/O devices and resolves conflict issues when two or more programs access a device at the same time.