Operating Systems Fundamentals PDF

OPERATING SYSTEMS FUNDAMENTALS WHAT IS OPERATING SYSTEM? Operating System commonly referred to as an OS – is a set of computer programs that manage the hardware and software resources of a computer. The OS processes electronic devices with a rational response to commands that are approved by the...

OPERATING SYSTEMS FUNDAMENTALS WHAT IS OPERATING SYSTEM? Operating System commonly referred to as an OS – is a set of computer programs that manage the hardware and software resources of a computer. The OS processes electronic devices with a rational response to commands that are approved by the system. FIVE CLASSIFICATIONS OF A COMPUTER OPERATING SYSTEM MULTI-USER: Allows two or more users to run programs at the same time. Some operating systems permit hundreds or even thousands of concurrent users. MULTI-PROCESSING: Supports running a program on more than one CPU. MULTITASKING: Allows more than one program to run concurrently. MULTI-THREADING: Allows different parts of a single program to run concurren. REAL TIME: Responds to input instantly. General-purpose operating systems, such as DOS and UNIX, are not real-time. ROLE OF AN OPERATING SYSTEM An operating system is a software which performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers. FUNCTIONS OF AN OS PROCESS MANAGEMENT: Every program running on a computer whether it is a background service or an application is called a process. DISK AND FILE SYSTEMS: All operating systems include support for a variety of file systems. Modern file systems are made up of directories. While the idea is similar in concept across all general purpose file systems, some differences in implementation exist. NETWORKING: The network links separate computers together from different locations. Most current operating systems are capable of using the TCP/IP networking protocols. That means that one system can appear on a network of the other and share resources such as files, printers, and scanners using either wired or wireless connections. SECURITY: Important in any computer system. The operating system provides a level of security that can protect your computer and the data on System security is based on two principles: a. That the operating system provides access to many resources either directly or indirectly. That could mean files on a local disk, privileged system calls, personal information about user, and the services offered by the programs running on the system. b. That the operating system is capable of distinguishing between those who are allowed to access the resource and those who are forbidden to do so. While some systems may simply distinguish between “privileged” and “non-privileged”, most commonly have a form of register identity such as a user name. Requesters of information are further divided into two categories: 1. Internal security in an already running program. On some systems, once a program is running, it has no limitations, but commonly, the program has an identity which it keeps. That identity is used to check all of its requests for resources. 2. External security as in a new request from outside the computer. This could be in the form of a new request from outside the system such as a login at a connected console or some kind of network connection. To establish identity, there may be a process of authentication MEMORY MANAGEMENT This function is referred to as virtual memory management and increases the amount of memory available for each process by making the disk storage seem like main memory. There is a speed penalty associated with using disks or other slower storage as memory. If running processes requires significantly more RAM than is available, the system may start “thrashing” or slowing down. Types of memory in a computer system are: High-speed cache: This is fast, relatively small amounts of memory that are available to the CPU through the fastest connections. Cache controllers predict which pieces of data the CPU will need next and pull it from main memory into high-speed cache to speed up system performance. Main memory: This is the RAM that you see measured in megabytes when you buy a computer. Secondary memory: This is most often some sort of rotating magnetic storage that keeps applications and data available to be used, and serves as virtual RAM under the control of the operating system. GRAPHICAL USER INTERFACE A GUI is basically the pictures you see on the screen that help you navigate your computer. They include the icons and the menus. Many operating systems allow the user to install or create any user interface they desire.Graphical user interfaces tend to change and evolve over time. DEVICE DRIVERS A device driver is a specific type of computer software developed to allow interaction with hardware devices. Typically, this constitutes an interface for communicating with the device through the specific computer bus or communications subsystem that the hardware is connected to. APPLICATION INTERFACE Just as drivers provide a way for applications to make use of hardware subsystems without having to know every detail of the hardware's operation, application program interfaces (APIs) let application programmers use functions of the computer and operating system without having to directly keep track of all the details in the CPU's operation. COMMON OPERATING SYSTEMS 1. MS DOS 2. MacOS 3. UNIX 4. LINUX 5. GNU 6. Mobile OS 7. Windows 8. Windows 1.0 (1983) 9. Windows 2.0 10. Windows 3.0 11. Windows 3.1 12. Windows 95 13. Windows 98 14. Windows ME 15. Windows XP 16.Windows Vista 17.Windows 7 18.Windows 8 19.Windows 10 20.Windows 11 DOS – MS DOS (MICROSOFT DISK OPERATING SYSTEM) An operating system for x86 based personal computers mostly developed by Microsoft. Collectively, MS-DOS, it’s rebranding as IBM PC DOS, and some operating systems attempting to be compatible with MS-DOS, are sometimes referred to as "DOS" (which is also the generic acronym for disk operating system). MS-DOS was the main operating system for IBM PC compatible personal computers during the 1980s, from which point it was gradually superseded by operating systems offering a graphical user interface (GUI), in various generations of the graphical Microsoft Windows operating system. MAC OS Previously Mac OS X and later OS X) is a series of proprietary graphical operating systems developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers Within the market of desktop, laptop and home computers, and by web usage, it is the second most widely used desktop OS after Microsoft Windows. UNIX The UNIX operating system was developed in the 60’s and 70’s by a group of AT & T employees at Bell Labs. Unix is used by both servers and workstations and is the basis for a wide variety of other operating systems. The UNIX system was designed to be portable, multi-tasking and multi-user in a time-sharing configuration. There are various concepts that are unique to all UNIX systems. These concepts include: 1. The use of plain text for storing data 2. A hierarchical file system 3. Treating devices and certain types of inter-process communication as files 4. The use of a large number of small programs that can be strung together through a command line interpreter using “pipes” as opposed to a single monolithic program with the same functionality. LINUX The first Linux systems were completed in 1992 by combining system utilities and libraries from the GNU project which is another operating system Linux is used as an operating system for a wider variety of computer hardware than any other operating system including desktop computers, super computers, mainframes, and embedded devices such as cell phones. Linux is packaged for different uses in Linux distributions which contain the kernel along with a variety of other software packaged tailored to its intended use. It can run software from other companies such as Mac and Windows. This makes it hugely advantageous to the open market as inter- operability in an operating system is rather uncommon as of late. GNU Is also a free software operating system. Its name is a recursive acronym for “GNU’s not Unix” which was chosen because while it is Unix based, it is freeware and contains no Unix code. As of 2007, GNU is being actively developed although a complete system has not yet been released. MOBILE OS Mobile operating system is an operating system for mobile phones, tablets, smartwatches, 2-in-1 PCs (that can be convert to a laptop mode or detach and work as a tablet mode), smart speaker, or other mobile devices. Mobile devices with mobile communications abilities (e.g., smartphones) contain two mobile operating systems – the main user-facing software platform is supplemented by a second low-level proprietary real-time operating system which operates the radio and other hardware. Research has shown that these low-level systems may contain a range of security vulnerabilities permitting malicious base stations to gain high levels of control over the mobile device ANDROID OS (based on the Linux kernel) is a mobile operating system hosted by Linux Foundation, together with support from the Tizen Association, guided by a Technical Steering Group composed of Intel and Samsung. TIZEN is from Kai. It is based on Firefox OS/Boot to Gecko. Unlike most mobile operating system which focus on smartphones, KaiOS was developed mainly for feature phones, giving these access to more advanced technologies usually found on smartphones, such as app stores and Wi-Fi/4G capabilities. KAIOS Android is a mobile operating system developed by Google. The base system is open-source, but the apps and drivers which provide functionality are increasingly becoming closed-source. Besides having the largest installed base worldwide on smartphones, it is also the most popular operating system for general purpose. WINDOWS Windows or win is an operating environment created by Microsoft that provides an interface known as Graphical User Interface (GUI) for computers. Windows eliminates the need to memorize commands for the command line (MS-DOS), by using a mouse to navigate through menus, dialog boxes, buttons, tabs, and icons. Microsoft Windows was first introduced with version 1.0 on November 10, 1983. Since its release, there have been over a dozen versions of Windows. The most current version of Windows for end users is Windows 10. WINDOWS 1.0 (1983) The first Windows version introduced the "MS-DOS Executive," which was a DOS application that ran applications in side-by-side windows. It was rarely used. WINDOWS 2.0 (1987) Windows 2.0 introduced overlapping, resizable windows with more flexibility. Soon after, Windows/386 was released for Intel's 386 CPU, which could run multiple DOS applications simultaneously (Windows 2.0 was renamed Windows/286). Windows was becoming more useful, and a handful of companies adopted it as an operating environment. WINDOWS 3.0 (1990) Windows 3.0 was the first popular version of Windows with a new, colorful user interface that was far superior to Windows 2.0. Although the PC still booted into DOS, Windows 3.0 included a DOS extender that broke the 1MB memory limit (a major breakthrough). Windows 3.0 was widely used to multitask. WINDOWS 3.1 (1992) Windows 3.1 was the first product to fully utilize graphical user interface for ease of controlling what the computer would do. Windows also now allowed the user to multitask, meaning the user could now run multiple applications at once without having to close out of each program before running FEATURES PLUG AND PLAY: Allows hardware devices to be automatically installed into the computer with the proper software. Does not require jumpers to be played with. 32 BIT: Operating system allowing the computer to run faster and more efficiently. REGISTRY: Combines the power of multiple configuration files into two files, allowing the system configurations to be located easier. MEMORY: Windows 95 had an improved memory handling processes compared to Windows 3.11. RIGHT MOUSE CLICK: Allows you new access and text manipulation by utilizing both buttons instead of one. CD-PLAYER: Enhanced CD-Player with improved usability and AutoPlay feature. WINDOWS 95 Windows 95 was the first 32-bit Windows operating system and a major upgrade from Windows 3.1. It used an entirely different user interface that incorporated the now-common Start menu and Taskbar. It was also the first time the computer booted directly into Windows, rather than being loaded after booting up in DOS. FEATURES PROTECTION: Allows hardware devices to be automatically installed into the computer with the additional protection for important files on your computer such as backing up your registry automatically. proper software. IMPROVED SUPPORT: Does not require jumpers to be played with. Improved support for new devices such as AGP, DirectX, DVD, USB, MMX, etc. FAT32: had the capability of converting your drive to FAT32 without losing any information. INTERFACE: Users of Windows 95 and NT would enjoy the same easy interface. INTERNET EXPLORER 4.0: Included Internet Explorer 4.0. CUSTOMIZABLE TASKBAR: Windows added many nice new features to the taskbar which 95 and NT did not have. ACTIVE DESKTOP: Included Active Desktop which allowed for users to customize their desktop with the look of the Internet. WINDOWS 98 WORKSPACE Was an upgrade to Windows 95 that tightly integrated the Internet Explorer Web browser with the OS. In 1999, Windows 98 Second Edition fixed numerous bugs and upgraded its applications FEATURES 1. Increased uptime of the system and significantly fewer OS reboot scenarios. 2. Windows Installer tracks applications and recognizes and replaces missing components. 3. Protects memory of individual apps and processes to avoid a single app bringing the system down. 4. Encrypted File Systems protects sensitive data. 5. Secure Virtual Private Networking (VPN) supports tunneling in to private LAN over public Internet. 6. Personalized menus adapt to the way you work. 7. Multilingual version allows for User Interface and help to switch, based on logon. 8. Includes broader support for high-speed networking devices, including Native ATM and cable modems. 9. Supports Universal Serial Bus (USB) and IEEE 1394 for greater bandwidth devices. WINDOWS ME OR WINDOWS MILLENNIUM (2000) An upgrade to Windows 98. ME had a shorter boot time, but no longer could be booted into DOS only (DOS sessions could still be run in a Windows window FEATURES REVERT BACK TO BACKUP OF COMPUTER: Automatically restore an old backup in case files are corrupted or deleted. PROTECT IMPORTANT SYSTEM FILES: Windows Me allowed the user to protect important system files and would not allow these files to be modified by any type of other software. MOVIE EDITOR: Allowed users to edit and or combine Microsoft movie files. Importing movies required additional hardware. WINDOWS MEDIA PLAYER:Included Media Player 7, which enabled users a more advanced way of listening and organizing their media files. WINDOWS XP (EXPERIENCED) 2001 Windows XP is designed more for users who may not be familiar with all of Windows features and has several new abilities to make the Windows experience easier for those users. FEATURES NEW INTERFACE: A completely new look and ability to change the look. UPDATES: New feature that automatically obtains updates from the Internet. IM INTERNET EXPLORER 6: Includes internet explorer 6 and new MULTILINGUAL SUPPORT: Added support for different languages WINDOWS VISTA (2007) A client version of Windows that was widely criticized for its bugs and behavior. Windows Server 2008 was the server counterpart. FEATURES 1. Windows Aero, a completely new GUI and unlike any previous version of Windows. 2. Basic file backup and restore. 3. Improved DVD support with the ability to easily create custom DVD movies. 4. Easy transfer, a feature that allows you to easily transfer files from an older computer to the new computer. 5. File encryption. 6. Instant search available through all Explorer windows. 7. Support for DirectX 10. 8. Self-healing, the ability to automatically detect and correct problems that may be encountered on the computer. 9. Shadow copy, a feature that allows you to recover deleted files. 10. Improved photo gallery and control of photographs. 11. Windows Sidebar and gadgets that allows you to add an almost endless list of different gadgets. More parental control. Improved Windows Calendar, with the ability to set tasks and appointments. WINDOWS 7 Includes features and functions along with its predecessor, Windows Vista. It also improved on Vista in several areas. Features includes new Windows button, but most of the new features, such as improvements to the taskbar, were designed to make the user more productive. FEATURES Advancements in touch, speech and handwriting recognition, support for virtual hard disks, support for additional file formats, improved performance on multi-core processors, improved boot performance, and kernel improvements. WINDOWS 8 The previous client version of Windows. Introduced in October 2012, Windows 8 featured desktop-tablet integration. Updated to Windows 8.1 a year later, Windows 8 was superseded by Windows 10 in 2015. WINDOWS 10 A mode in Windows 10 that runs apps downloaded and installed only from the Microsoft Store. Microsoft has not divulged the meaning of "S," but "Secure" has been suggested because users cannot install apps from a CD/DVD, USB drive or their network. Like all Windows 10 versions, OneDrive cloud storage is included. Edge is the default Web browser, and schools can provision machines from a USB drive. Windows 10 S was introduced in 2017; however, the April 2018 update officially changed the name from "Windows 10 S" to "Windows 10 in S mode." FEATURES LOCKSCREEN: The Lock screen serves the same purpose it does on a phone: It gives a quick glance at the time, the date, WiFi signal strength, the weather, and (on laptops and tablets) battery charge. Newly installed and downloaded can add informational tidbits to lock screen. HYBRID START MENU: Gives direct access to apps frequently use, or installed important commands and places like Power and “All apps are displayed. FILE EXPLORER: This “app” is the standard desktop window, showing the contents of drives and folders. CHANGE ACCOUNT SETTINGS: Takes you directly to the Settings→Account screen, where you can change your account picture, password, login method, and other details of your account—and you can create accounts for other family members. LOCK: This command takes you back to the Lock screen. This is an ideal way to protect your PC from unauthorized use. Whatever you had running remains open behind the scenes. When you log in again, you’ll find all your open programs and documents exactly as you left them. SIGN OUT: When you choose “Sign out,” Windows closes all open programs and documents (giving you an opportunity to save any unsaved documents first). It then presents a new Login screen so that somebody else can log in. SETTINGS: It is where the settings and preferences of your found. DOCUMENTS: This command opens up Documents folder, designed to store all saved documents —everything except music, pictures, and videos, which get folders of their own. CORTANA SEARCH BAR: Is Microsoft's personal productivity assistant that helps yousaves time to search. Similar to google assistant and SIRI. TASK VIEW: A task switcher and virtual desktop system introduced inWindows 10 and is among the first features new to Windows TASKBAR: Is an element of an operating system located at the bottom of the screen. It allows you to locate and launch programs through Start and the Start menu, or view any program that's currently open. STATUS BAR: lets you see brief information about the currently selected files and switch the folder layout. NOTIFICATIONS: Displays a list of your current notifications, organized into ongoing and event-based notifications. AERO PEEK: Use to preview the desktop when you move your mouse to the Show Desktop button at the end of the taskbar.