jvzoo
Comodo SSL Expand
Collapse

kimbersoft.com Study

FT.png

Computer Operating Systems

Page:   Technical Fast Track   .   Today   .   Tomorrow   .   Knowledge Management   

Page:   Technical Fast Track   .   Hardware    Software   Programming   .   Networking   Operation   Systems  

Objective   10/12/2017

Operating Systems documentation.

What IS an Operating System ?   10/12/2017

from Wikipedia
The History of Operating Systems

An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. All computer programs, excluding firmware, require an operating system to function.

Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources.

For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware,[1][2] although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers.

The dominant desktop operating system is Microsoft Windows with a market share of around 83.3%. macOS by Apple Inc. is in second place (11.2%), and the varieties of Linux are collectively in third place (1.55%).[3] In the mobile (smartphone and tablet combined) sector, according to third quarter 2016 data, Android by Google is dominant with 87.5 percent and a growth rate 10.3 percent per year, followed by iOS by Apple with 12.1 percent and a per year decrease in market share of 5.2 percent, while other operating systems amount to just 0.3 percent.[4] Linux distributions are dominant in the server and supercomputing sectors. Other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications.


Kernel (operating system)   10/12/2017

from Wikipedia

The kernel is a computer program that is the core of a computer's operating system, with complete control over everything in the system.[1] On most systems, it is one of the first programs loaded on start-up (after the bootloader). It handles the rest of start-up as well as input/output requests from software, translating them into data-processing instructions for the central processing unit. It handles memory and peripherals like keyboards, monitors, printers, and speakers.

A kernel connects the application software to the hardware of a computer.

The critical code of the kernel is usually loaded into a protected area of memory, which prevents it from being overwritten by applications or other, more minor parts of the operating system. The kernel performs its tasks, such as running processes and handling interrupts, in kernel space. In contrast, everything a user does is in user space: writing text in a text editor, running programs in a GUI, etc. This separation prevents user data and kernel data from interfering with each other and causing instability and slowness.[1]

The kernel's interface is a low-level abstraction layer. When a process makes requests of the kernel, it is called a system call. Kernel designs differ in how they manage these system calls and resources. A monolithic kernel runs all the operating system instructions in the same address space for speed. A microkernel runs most processes in user space,[2] for modularity.[3]

Microkernel   10/12/2017

from Wikipedia

The kernel is a computer program that is the core of a computer's operating system, with complete control over everything in the system.[1] On most systems, it is one of the first programs loaded on start-up (after the bootloader). It handles the rest of start-up as well as input/output requests from software, translating them into data-processing instructions for the central processing unit. It handles memory and peripherals like keyboards, monitors, printers, and speakers.

A kernel connects the application software to the hardware of a computer.

The critical code of the kernel is usually loaded into a protected area of memory, which prevents it from being overwritten by applications or other, more minor parts of the operating system. The kernel performs its tasks, such as running processes and handling interrupts, in kernel space. In contrast, everything a user does is in user space: writing text in a text editor, running programs in a GUI, etc. This separation prevents user data and kernel data from interfering with each other and causing instability and slowness.[1]

The kernel's interface is a low-level abstraction layer. When a process makes requests of the kernel, it is called a system call. Kernel designs differ in how they manage these system calls and resources. A monolithic kernel runs all the operating system instructions in the same address space for speed. A microkernel runs most processes in user space,[2] for modularity.[3]


Android   10/12/2017    Android Developer

from Wikipedia
Android Developer
The Android Operating System and Applications

Android is a mobile operating system developed by Google, based on the Linux kernel and designed primarily for touchscreen mobile devices such as smartphones and tablets. Android's user interface is mainly based on direct manipulation, using touch gestures that loosely correspond to real-world actions, such as swiping, tapping and pinching, to manipulate on-screen objects, along with a virtual keyboard for text input. In addition to touchscreen devices, Google has further developed Android TV for televisions, Android Auto for cars, and Android Wear for wrist watches, each with a specialized user interface. Variants of Android are also used on game consoles, digital cameras, PCs and other electronics.

Initially developed by Android Inc., which Google bought in 2005, Android was unveiled in 2007, along with the founding of the Open Handset Alliance – a consortium of hardware, software, and telecommunication companies devoted to advancing open standards for mobile devices. Beginning with the first commercial Android device in September 2008, the operating system has gone through multiple major releases, with the current version being 8.0 "Oreo", released in August 2017. Android applications ("apps") can be downloaded from the Google Play store, which features over 2.7 million apps as of February 2017. Android has been the best-selling OS on tablets since 2013, and runs on the vast majority[a] of smartphones. As of May 2017, Android has two billion monthly active users, and it has the largest installed base of any operating system.

Android's source code is released by Google under an open source license, although most Android devices ultimately ship with a combination of free and open source and proprietary software, including proprietary software required for accessing Google services. Android is popular with technology companies that require a ready-made, low-cost and customizable operating system for high-tech devices. Its open nature has encouraged a large community of developers and enthusiasts to use the open-source code as a foundation for community-driven projects, which deliver updates to older devices, add new features for advanced users or bring Android to devices originally shipped with other operating systems. The extensive variation of hardware in Android devices causes significant delays for software upgrades, with new versions of the operating system and security patches typically taking months before reaching consumers, or sometimes not at all. The success of Android has made it a target for patent and copyright litigation between technology companies.

iOS 9   10/12/2017    Developing for iOS 9

from Wikipedia iOS 9
Flashback - History of iOS (iPhone OS to iOS 8)

iOS 9 is the ninth major release of the iOS mobile operating system developed by Apple Inc., being the successor to iOS 8. It was announced at the company's Worldwide Developers Conference on June 8, 2015, and was released on September 16, 2015. It was succeeded by iOS 10 on September 13, 2016.[1]

iOS 9 incorporated many feature updates to built-in apps. Most notably, Notes received the ability to draw sketches with different tools, image insertion, prominent visual appearance for website links and map locations, and advanced list formatting; an all-new Apple News app aggregates articles from different sources; and Apple Maps received mass transit support, although in a limited number of locations at launch. Major new system updates include proactivity, where Siri and advanced search are combined to make the operating system more contextually aware of information (such as time and location), and can provide the user with information ahead of time. For searching, the proactive intelligence can display instant results in a widget-like format, including weather, sports, news, and more. iOS 9 also added multiple forms of multitasking to the iPad. In iOS 9.3, Apple added a Night Shift mode that changes the color of the device's display to a warmer, less "blue light" shade, to prevent any potential negative screen effect on users' circadian rhythms. Additionally, iOS 9 brought new user experience functions, including Quick Actions, and Peek and Pop, based on the touch-sensitive display technology in the iPhone 6S. Quick Actions are shortcuts on home screen app icons. Users can preview ("Peek") at content without moving away from the current screen before they enter ("Pop") the previewed content into full view.

Reception of iOS 9 was positive. Critics praised proactivity and Siri for making the Notification Center a central location for all information, and the potential for future updates to improve the functionality. The new multitasking features for the iPad were complimented, as were drawing and photo insertion in the Notes app. However, Apple News was criticized for a low number of decent-looking articles, and Apple Maps was criticized for the limited geographical availability of mass transit support.

Five days after release, Apple announced that iOS 9 had been installed on more than 50% of "active" iOS devices, which Apple described as the "fastest adoption rate ever for a new operating system".

Linux   10/12/2017

from Wikipedia    Linux
Introduction to Linux

Linux is a name which broadly denotes a family of free and open-source software operating system distributions built around the Linux kernel. The defining component of a Linux distribution is the Linux kernel,[12] an operating system kernel first released on September 17, 1991 by Linus Torvalds.[13][14][15] Many Linux distributions use the word "Linux" in their name. The Free Software Foundation uses the name GNU/Linux to refer to the operating system family, as well as specific distributions, to emphasize that most Linux distributions are not just the Linux kernel, and that they have in common not only the kernel, but also numerous utilities and libraries, a large proportion of which are from the GNU project. This has led to some controversy.[16][17]

Linux was originally developed for personal computers based on the Intel x86 architecture, but has since been ported to more platforms than any other operating system.[18] Because of the dominance of the Linux kernel-based Android OS on smartphones, Linux has the largest installed base of all general-purpose operating systems.[19] Linux is also the leading operating system on servers and other big iron systems such as mainframe computers, and is used on 99.6% of the TOP500 supercomputers.[20][21] It is used by around 2.3% of desktop computers.[22][23] The Chromebook, which runs the Linux kernel-based Chrome OS, dominates the US K–12 education market and represents nearly 20% of the sub-$300 notebook sales in the US.[24] Linux also runs on embedded systems – devices whose operating system is typically built into the firmware and is highly tailored to the system. This includes TiVo and similar DVR devices, network routers, facility automation controls, televisions,[25][26] video game consoles and smartwatches.[27] Many smartphones and tablet computers run Android and other Linux derivatives.[28]

The development of Linux is one of the most prominent examples of free and open-source software collaboration. The underlying source code may be used, modified and distributed?—?commercially or non-commercially?—?by anyone under the terms of its respective licenses, such as the GNU General Public License.

Typically, Linux is packaged in a form known as a Linux distribution (or distro for short) for both desktop and server use. Some of the most popular and mainstream Linux distributions[29][30][31] are Arch Linux, CentOS, Debian, Fedora, Gentoo Linux, Linux Mint, Mageia, openSUSE and Ubuntu, together with commercial distributions such as Red Hat Enterprise Linux and SUSE Linux Enterprise Server. Distributions include the Linux kernel, supporting utilities and libraries, many of which are provided by the GNU Project, and usually a large amount of application software to fulfil the distribution's intended use. Desktop Linux distributions include a windowing system, such as X11, Mir or a Wayland implementation, and an accompanying desktop environment such as GNOME or KDE Plasma 5; some distributions may also include a less resource-intensive desktop, such as LXDE or Xfce. Distributions intended to run on servers may omit all graphical environments from the standard install, and instead include other software to set up and operate a solution stack such as LAMP. Because Linux is freely redistributable, anyone may create a distribution for any intended use.

Mac OS   10/12/2017

from Wikipedia
History of Mac OS

macOS (previously Mac OS X and later OS X) is the current series of Unix-based graphical operating systems developed and marketed by Apple Inc. designed to run on Apple's Macintosh computers ("Macs"). It has been preinstalled on all Macs since 2002. 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.[7][8]

Launched in 2001 as Mac OS X, the series is the latest in the family of Macintosh operating systems. Mac OS X succeeded "classic" Mac OS, which was introduced in 1984, and the final release of which was Mac OS 9 in 1999. An initial, early version of the system, Mac OS X Server 1.0, was released in 1999. The first desktop version, Mac OS X 10.0, followed in March 2001. Releases were code named after big cats from the original release up until OS X 10.8 Mountain Lion. Beginning in 2013 with OS X 10.9 Mavericks, releases have been named after landmarks in California.[9] Apple changed the original name "Mac OS X" to "OS X" in 2012 and then to "macOS" in 2016, adopting the nomenclature that it uses for their other operating systems, iOS, watchOS, and tvOS. The latest version of macOS is macOS High Sierra, which was publicly released in September 2017.

macOS is based on technologies developed at NeXT between 1985 and 1997, when Apple acquired the company. The "X" in Mac OS X and OS X is pronounced "ten", as it is the Roman numeral for the number 10. The X was a prominent part of the operating system's brand identity, and was used to showcase its Unix compatibility; UNIX 03 certification was achieved for the Intel version of Mac OS X 10.5 Leopard[10] and all releases from Mac OS X 10.6 Snow Leopard up to the current version also have UNIX 03 certification.[11][12][13][14][15][16][17] macOS shares its Unix-based core, named Darwin, and many of its frameworks with iOS,[18] tvOS and watchOS. A heavily modified version of Mac OS X 10.4 Tiger was used for the first-generation Apple TV.[19]

Apple also used to have a separate line of releases of Mac OS X designed for servers. Beginning with Mac OS X 10.7 Lion, the server functions were made available as a separate package on the Mac App Store.

Releases of Mac OS X from 1999 to 2005 can run only on the PowerPC-based Macs from the time period. After Apple announced that they were switching to Intel CPUs from 2006 onwards, a separate version of Mac OS X 10.4 Tiger was made and distributed exclusively with early Intel-based Macs; it included an emulator known as Rosetta, which allowed users to run most PowerPC applications on Intel-based Macs. Mac OS X 10.5 Leopard was released as a Universal binary, meaning the installer disc supported both Intel and PowerPC processors. In 2009, Apple released Mac OS X 10.6 Snow Leopard, which ran exclusively on Intel-based Macs. In 2011, Apple released Mac OS X 10.7 Lion, which no longer supported 32-bit Intel processors and also did not include Rosetta. All versions of the system released since then run exclusively on 64-bit Intel CPUs and do not support PowerPC applications.

Microsoft Windows   10/12/2017

from Wikipedia
Microsoft Windows
History Of Microsoft Windows And it's Evolution

Microsoft Windows, or simply Windows, is a metafamily of graphical operating systems developed, marketed, and sold by Microsoft. It consists of several families of operating systems, each of which cater to a certain sector of the computing industry with the OS typically associated with IBM PC compatible architecture. Active Windows families include Windows NT and Windows Embedded; these may encompass subfamilies, e.g. Windows Embedded Compact (Windows CE) or Windows Server. Defunct Windows families include Windows 9x, Windows Mobile and Windows Phone.

Microsoft introduced an operating environment named Windows on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUIs).[3] Microsoft Windows came to dominate the world's personal computer (PC) market with over 90% market share, overtaking Mac OS, which had been introduced in 1984. Apple came to see Windows as an unfair encroachment on their innovation in GUI development as implemented on products such as the Lisa and Macintosh (eventually settled in court in Microsoft's favor in 1993). On PCs, Windows is still the most popular operating system. However, in 2014, Microsoft admitted losing the majority of the overall operating system market to Android,[4] because of the massive growth in sales of Android smartphones. In 2014, the number of Windows devices sold was less than 25% that of Android devices sold. This comparison however may not be fully relevant, as the two operating systems traditionally target different platforms. Still, numbers for server use of Windows (that are comparable to competitors) show one third market share, similar to for end user use.

As of September 2016, the most recent version of Windows for PCs, tablets, smartphones and embedded devices is Windows 10. The most recent versions for server computers is Windows Server 2016. A specialized version of Windows runs on the Xbox One video game console.[5]

UNIX   10/12/2017

from Wikipedia    UNIX
AT&T Archives: The UNIX Operating System

Unix (/'ju?n?ks/; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, development starting in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.[3]

Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties from the late 1970s, leading to a variety of both academic and commercial variants of Unix from vendors such as the University of California, Berkeley (BSD), Microsoft (Xenix), IBM (AIX) and Sun Microsystems (Solaris). AT&T finally sold its rights in Unix to Novell in the early 1990s, which then sold its Unix business to the Santa Cruz Operation (SCO) in 1995,[4] but the UNIX trademark passed to the industry standards consortium The Open Group, which allows the use of the mark for certified operating systems compliant with the Single UNIX Specification (SUS). Among these is Apple's macOS,[5] which is the Unix version with the largest installed base as of 2014.

From the power user's or programmer's perspective, Unix systems are characterized by a modular design that is sometimes called the "Unix philosophy", meaning that the operating system provides a set of simple tools that each perform a limited, well-defined function,[6] with a unified filesystem as the main means of communication[3] and a shell scripting and command language to combine the tools to perform complex workflows. Aside from the modular design, Unix also distinguishes itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language[7] that allowed Unix to reach numerous platforms.

Many Unix-like operating systems have arisen over the years, of which Linux is the most popular, having displaced SUS-certified Unix on many server platforms since its inception in the early 1990s. Android, the most widely used mobile operating system in the world, is in turn based on Linux.

Alexa.png dmoz.png

kimbersoft.com is hosted on a re-seller Virtual Private Server

This page was last updated October 12th, 2017 by kim

Where wealth like fruit on precipices grew.

SEO Links    SEM Links   .   Traffic   .   Traffup   

kimbersoft.com YouTube.png kimbersoft.com google+.png kimbersoft.com Twitter