Computer and Operating Concepts

operating system (OS)

is a type of system software that acts as the master controller for all activities that take place within a computer system.

Manage processor resources to handle simultaneous input, output, and processing tasks.

Manage memory by allocating space for all the programs and data that are in use during a computing session.

Keep track of storage resources so that files and programs can be found and manipulated.

Ensure that input and output proceed in an orderly manner by communicating with peripheral devices.

Establish basic elements of the user interface such as the appearance of the desktop, menus, and tool bars.

Application Software

is a set of computer programs that helps a person carry out a task. e.g. Libre office, firefox, Gimp, Transmission

Process Allocation

OS handles task by ______

Multitasking
Multi threading
Multi Processing

Process allocation can be one or combination of three methods:

1. provides process and memory management services that allow two or more tasks, jobs, or programs to run simultaneously.

2. Allows multiple parts, or threads of a single program to run simultaneously.

3. Delegation of tasks, programs or processes into multiple cores

Single-user
Multi-user

Classifications of OS:

1. deals with one set of input devices those that can be controlled by one user at a time. - Some smart phones and Tablets fit into this category.

2. allows a single, centralized computer to deal with simultaneous input, output, and processing requests from many users.

Windows NT Family
UNIX
Linux or Unix-like
Other OS

Types of Operating System

Windows XP

a personal computer operating system produced by Microsoft as part of the Windows NT family.

Microsoft discontinued it’s extended support last April 8, 2014

UNIX

System V
BSD

System V

One of the first commercial versions of the Unix operating system. Developed by AT&T and first released in 1983.
e.g. AIX, HP-UX and Solaris.

BSD

An operating system based on Research Unix, developed by the Computer Systems Research Group (CSRG) at UC, Berkeley.

Proprietary at first but soon become the basis of other open-source unix.

Free
Open
Net
DragonFly

BSD Family (4)

GNU/Linux

An operating system and an extensive collection of free computer software.

Unix-like, but differs from Unix by being free software and containing no Unix code.

Debian
Red hat
Open SUSE
Ubuntu
Bodhi
Bayanihan

GNU/Linux (6)

React OS

Is a Community, Open source, Collaborative, Compatible, Free operating system.

A lightweight built from scratch.

Able to run most windows apps.

Not a linux.

Temple OS

(formerly J OS, SparrowOS and LoseThos) is a biblical-themed lightweight operating system designed to be the Third Temple prophesied in the Bible.

A modern x86-64 Commodore system.

Why GNU/Linux?

Free

Distributed along with its source code under the terms of a GPL (General Public License). Open source.

Basically secure, stable, and fast.

Because big C’s are already moving to GNU/Linux.

Due to it’s licensing policy, it is easier to develop utilities and software.

*We are working in a company (CAAP) that uses GNU/Linux (Thalix & SL).

Boot Process

The sequence of events that occurs between the time of turning on a computer and the time that it is ready to accept user commands.

Power up
Start boot program
Power-on self-test (POST)
Identify peripheral devices
Load operating system
Check configuration and customization

6 major events boot process:

1. Power is distributed to the computer circuitry by turning on the power switch.

2. he microprocessor begins to execute the boot-strap program that is stored in ROM.

3. The computer performs diagnostic tests of several crucial system components.

4. The computer identifies any peripheral devices that are connected and checks their settings

5. The operating system is copied from the hard disk to RAM.

6.The microprocessor reads configuration data and executes any customized startup routines specified by the user.

User Interface

the combination of hardware and software that helps people and computer communicate with each other.

Basically, it consist of a display device, mouse, and keyboard.

Graphical User Interface (GUI)
Command line Interface (CLI)

User Interface 2 display environments

/bin folder

is a standard subdirectory of the root directory in Unix-like operating systems that contains the executable programs.

/boot folder

Contains all the boot related info files and folders such as grub.conf, vmlinuz image aka kernel etc.

/dev folder

Is the location of special or device files. The two major devices are BLOCK and CHARACTER.

/etc folder

Is where configuration files and directories are located.

/home folder

also called a login directory, is the directory on Unix-like OS that serves as the repository for a user's personal files, directories and programs.

/lib folder

is a library files directory which contains all helpful library files as well as kernel modules used by the system.

/lost+found folder

Files that would normally be lost because of directory corruption. Recovered bits of corrupted files.

/tmp folder

A directory made available for applications that need a place to create temporary files.

/var folder

Contains variable data like system logging files, mail and printer spool directories, and transient and temporary files.

/usr folder

Contains all the user binaries, their documentation, libraries, header files, etc. Sometimes referred as 'User System Resources'.

True

True or False:
Everything inside the GNU/Linux is a file.

Partition

- Is a logical area of a disk as a result of division process called partitioning.

Filesystem

The structure and logic rules used to manage the groups of information and their names is called a "file system"

FAT(12, 16, 32), exFAT, NTFS

File Systems (Supported in Linux) (yung nakapula lang)

KDE
Mate
Gnome
Cinnamon
Budgie
LXDE
Xfce

Desktop Environments

Bourne Again SHell (BASH)

On-the-fly compiler that translates commands into sequence of bits understood by the machine.

Sometimes called “interpreter” .

Created by Stephen Bourne.

True

True or False

In GNU/Linux, characters are case sensitive and space sensitive between command & parameters. Multiple spaces though are ignored.

HOME
PATH

Common Environment (is also a variable)

$echo $HOME
$echo $PATH

Displaying Environment value

tilde (~)

$HOME is also a ______ character?