Operating Systems Flashcards

Flashcards based on lecture notes about Operating Systems.

Operating System

A system software that acts as an intermediary/interface between a user of a computer and the computer hardware.

Operating System Goals

Execute user programs and make solving user problems easier.

Booting

The process of starting an operating system.

Power On Switch

Sends electricity to the motherboard during booting.

BIOS (Basic Input/Output System)

The BIOS chip takes over during booting if the power supply is good.

Real Mode

CPU is only capable of using approximately 1 MB of memory built into the motherboard.

Power-On Self Test (POST)

Makes sure that all hardware are working during booting.

MBR (Master Boot Record)

Contains a list of all of the partitions on your computer’s hard disk.

Bootstrap Loader

Follows basic instructions for starting up the rest of the computer, including the operating system after the MBR is found.

Early Kernel Initialization

A smaller core of the Kernel is activated.

BIOS

Firmware was stored in a ROM/EPROM chip known as firmware on the PC motherboard.

BIOS

Can be accessed during the initial phases of the boot procedure by pressing del, F2 or F10.

User Interface (UI)

Controls how you enter data and instructions and how information is displayed on the screen.

Command-line interface

Typing commands represented by short keywords or abbreviations or pressing special keys on the keyboard to enter data and instructions.

Graphical User Interface (GUI)

You interact with menus and visual images.

The First Generation (1940's to early 1950's)

No Operating System and all programming was done in absolute machine language.

The Second Generation (1955-1965)

First operating system (GMOS) was introduced and Single-stream batch processing systems.

The Third Generation (1965-1980)

Introduction of multiprogramming and development of Minicomputer.

The Fourth Generation (1980-Present Day)

Development of PCs and birth of Windows/MaC OS.

Multiprogramming Operating System

OS is used to execute more than one job simultaneously by a single processor.

Time-Sharing Operating Systems

Each task is given some time to execute so that all the tasks work smoothly.

Platform

The hardware required to run a particular operating system.

Intel platform (IBM-compatible)

Windows, DOS, UNIX, Linux

MS-DOS

Single User Single Tasking OS with command line user interface.

Microsoft Windows

The graphical Microsoft operating system designed for Intel-platform desktop and notebook computers.

Mac OS

User-friendly OS that runs on Mac hardware.

Linux

An open-source, cross-platform operating system that runs on desktops, notebooks, tablets, and smartphones.

Google Chrome OS

A popular thin client operating system.

Thin client

A computer with minimal hardware, designed for a specific task.

Server Operating Systems

Windows Server, UNIX, Linux

iOS

The Apple-created operating system for Apple tablets and phones.

Open Source (Linux Advantage)

Its source code is easily available. Anyone having programming knowledge can customize the operating system.

Security (Linux Advantage)

The Linux security feature is the main reason that it is the most favourable option for developers.

Free (Linux Advantage)

Biggest advantage is that it is free to use. We can easily download it, and there is no need to buy the license for it.

Lightweight (Linux Advantage)

The requirements for running Linux are much less than other operating system.

Stability (Linux Advantage)

Does not require to reboot the system to maintain performance levels.

Performance (Linux Advantage)

Provides high performance over different networks and is capable of handling a large number of users simultaneously.

Flexibility (Linux Advantage)

Very flexible and also provides various restriction options for specific computers. We can install only necessary components for a system.

Software Updates (Linux Advantage)

In Linux, the software updates are in user control. We can select the required updates.

Distributions/Distros (Linux Advantage)

There are many Linux distributions available in the market and We can choose any distros according to our needs.

Live CD/USB (Linux Advantage)

Almost all Linux distributions have a Live CD/USB option and allows us to try or run the Linux operating system without installing it.

Graphical User Interface (Linux Advantage)

A command-line based OS but it provides an interactive user interface like Windows.

Suitable for programmers (Linux Advantage)

Supports almost all of the most used programming languages such as C/C++, Java, Python, Ruby, and more.

Community Support (Linux Advantage)

Provides large community support and has many forums available on the web to assist users.

Privacy (Linux Advantage)

Takes care of user privacy as it never takes much private data from the user.

Networking (Linux Advantage)

Facilitates with powerful support for networking and provides various command-line tools.

Compatibility (Linux Advantage)

Compatible with a large number of file formats as it supports almost all file formats.

Installation (Linux Advantage)

The installation process takes less time and is much easy as it requires less user input.

Multiple Desktop Support (Linux Advantage)

Provides multiple desktop environment support for its enhanced use.

Multitasking (Linux Advantage)

A multitasking operating system as it can run multiple tasks simultaneously without affecting the system speed.

Heavily Documented for beginners (Linux Advantage)

There are many command-line options that provide documentation on commands, libraries, standards such as manual pages and info pages.

Utilities

Shell, Kernel, Hardware, User

UNIX Shell and Utilities

The shell used to be in the kernel but now is a utility outside of it and is easy to change/debug.