Editing History of operating systems (section)

==Microcomputers==
Beginning in the mid-1970s, a new class of small computers came onto the marketplace. Featuring 8-bit processors, typically the [[MOS Technology 6502]], [[Intel 8080]], [[Motorola 6800]] or the [[Zilog Z80]], along with rudimentary input and output interfaces and as much [[Random-access memory|RAM]] as practical, these systems started out as kit-based hobbyist computers but soon evolved into an essential business tool.

===Home computers===
While many eight-bit [[home computer]]s of the 1980s, such as the [[BBC Micro]], [[Commodore 64]], [[Apple II]], [[Atari 8-bit computers]], [[Amstrad CPC]], [[ZX Spectrum]] series and others could load a third-party disk-loading operating system, such as [[CP/M]] or [[GEOS (8-bit operating system)|GEOS]], they were generally used without one. Their built-in operating systems were designed in an era when [[floppy disk|floppy disk drives]] were very expensive and not expected to be used by most users, so the standard storage device on most was a [[tape drive]] using standard [[Compact Cassette|compact cassettes]]. Most, if not all, of these computers shipped with a built-in [[BASIC]] interpreter on ROM, which also served as a crude [[command-line interface]], allowing the user to load a separate [[disk operating system]] to perform [[file management]] commands and load and save to disk. The most popular{{citation needed|date=July 2015}} home computer, the Commodore 64, was a notable exception, as its DOS was on ROM in the disk drive hardware, and the drive was addressed identically to printers, modems, and other external devices.

Furthermore, those systems shipped with minimal amounts of [[computer memory]]&mdash;4-8 [[kilobyte]]s was standard on early home computers&mdash;as well as 8-bit processors without specialized support circuitry like an [[Memory Management Unit|MMU]] or even a dedicated [[real-time clock]]. On this hardware, a complex operating system's [[Overhead (computing)|overhead]] supporting multiple tasks and users would likely compromise the performance of the machine without really being needed. As those systems were largely sold complete, with a fixed hardware configuration, there was also no need for an operating system to provide drivers for a wide range of hardware to abstract away differences.

[[Video game]]s and even the available [[spreadsheet]], [[database]] and [[word processor]]s for home computers were mostly self-contained programs that took over the machine completely. Although [[integrated software]] existed for these computers, they usually lacked features compared to their standalone equivalents, largely due to memory limitations. Data exchange was mostly performed through standard formats like [[ASCII]] text or [[Comma-separated values|CSV]], or through specialized file conversion programs.

===Operating systems in video games and consoles===
Since virtually all video game consoles and [[Video game arcade cabinet|arcade cabinets]] designed and built after 1980 were true digital machines based on [[microprocessor]]s (unlike the earlier ''[[Pong]]'' clones and derivatives), some of them carried a minimal form of [[BIOS]] or built-in game, such as the [[ColecoVision]], the [[Master System|Sega Master System]] and the [[SNK]] [[Neo Geo (system)|Neo Geo]].

Modern-day game consoles and videogames, starting with the [[TurboGrafx-16|PC-Engine]], all have a minimal BIOS that also provides some interactive utilities such as [[memory card]] management, [[Compact Disc Digital Audio|audio]] or [[video CD]] playback, [[copy protection]] and sometimes carry [[libraries]] for developers to use etc. Few of these cases, however, would qualify as a true operating system.

The most notable exceptions are probably the [[Dreamcast]] game console which includes a minimal BIOS, like the [[PlayStation (console)|PlayStation]], but can load the [[Windows CE]] operating system from the game disk allowing easily porting of games from the [[IBM PC compatible|PC]] world, and the [[Xbox (console)|Xbox]] game console, which is little more than a disguised Intel-based [[IBM PC compatible|PC]] running a secret, modified version of [[Microsoft Windows]] in the background. Furthermore, there are [[Linux]] versions that will run on a [[Dreamcast]] and later game consoles as well.

Long before that, [[Sony]] had released a kind of [[Game development kit|development kit]] called the [[Net Yaroze]] for its first PlayStation platform, which provided a series of programming and developing tools to be used with a normal PC and a specially modified "Black PlayStation" that could be interfaced with a PC and download programs from it. These operations require in general a functional OS on both platforms involved.

In general, it can be said that videogame consoles and arcade coin-operated machines used at most a built-in [[BIOS]] during the 1970s, 1980s and most of the 1990s, while from the PlayStation era and beyond they started getting more and more sophisticated, to the point of requiring a generic or custom-built OS for aiding in development and expandability.

===Personal computer era===
[[File:Apple Lisa (Little Apple Museum) (8032162544).jpg|thumb|Apple Lisa running Lisa OS]]
The development of microprocessors made inexpensive computing available for the [[small business]] and hobbyist, which in turn led to the widespread use of interchangeable hardware components using a common interconnection (such as the [[S-100 bus|S-100]], SS-50, [[Apple II]], [[Industry Standard Architecture|ISA]], and [[Conventional PCI|PCI]] [[bus (computing)|bus]]es), and an increasing need for "standard" operating systems to control them. The most important of the early OSes on these machines was [[Digital Research]]'s [[CP/M]]-80 for the 8080 / 8085 / Z-80 CPUs. It was based on several Digital Equipment Corporation operating systems, mostly for the PDP-11 architecture. Microsoft's first operating system, [[Marc McDonald|MDOS/MIDAS]], was designed along many of the PDP-11 features, but for microprocessor based systems. [[MS-DOS]], or [[IBM PC DOS|PC DOS]] when supplied by IBM, was designed to be similar to CP/M-80.<ref>{{cite web|url=https://www.embedded.com/was-dos-copied-from-cp-m/|title=Was DOS copied from CP/M?|author=Bob Zeidman|date=August 6, 2016}}</ref> Each of these machines had a small boot program in ROM which loaded the OS itself from disk. The BIOS on the IBM-PC class machines was an extension of this idea and has accreted more features and functions in the 20 years since the first IBM-PC was introduced in 1981.

The decreasing cost of display equipment and processors made it practical to provide graphical user interfaces for many operating systems, such as the generic [[X Window System]] that is provided with many Unix systems, or other graphical systems such as [[Apple Computer|Apple]]'s [[classic Mac OS]] and [[macOS]], the [[RadioShack|Radio Shack]] Color Computer's [[OS-9|OS-9 Level II/Multi-Vue]], [[Commodore International|Commodore]]'s [[AmigaOS]], [[Atari TOS]], [[IBM]]'s [[OS/2]], and [[Microsoft Windows]]. The original GUI was developed on the [[Xerox Alto]] computer system at Xerox [[PARC (company)|Palo Alto Research Center]] in the early 1970s and commercialized by many vendors throughout the 1980s and 1990s.

Since the late 1990s, there have been three operating systems in widespread use on personal computers: [[Apple Inc.]]'s [[macOS]], the [[Open-source software|open source]] [[Linux]], and [[Microsoft Windows]]. Since 2005 and the [[Mac transition to Intel processors]], all have been developed mainly on the [[x86]] platform, although macOS retained [[PowerPC]] support until 2009 and Linux remains ported to a multitude of architectures including ones such as [[68k]], [[PA-RISC]], and [[DEC Alpha]], which have been long superseded and out of production, and [[SPARC]] and [[MIPS architecture|MIPS]], which are used in servers or embedded systems but no longer for desktop computers. Other operating systems such as AmigaOS and OS/2 remain in use, if at all, mainly by [[retrocomputing]] enthusiasts or for specialized embedded applications.

===Mobile operating systems===
{{unreferenced section|date=February 2015}}

[[File:Android phone.jpg|thumb|[[Android (operating system)|Android]] is the most used [[mobile operating system]].]]

In the early 1990s, [[Psion (company)|Psion]] released the [[Psion Series 3]] [[personal digital assistant|PDA]], a small mobile computing device. It supported user-written applications running on an operating system called [[EPOC (operating system)|EPOC]]. Later versions of EPOC became [[Symbian]], an operating system used for mobile phones from [[Nokia]], [[Ericsson]], [[Sony Ericsson]], [[Motorola]], [[Samsung]] and phones developed for [[NTT Docomo]] by [[Sharp Corporation|Sharp]], [[Fujitsu]] & [[Mitsubishi]]. [[Symbian]] was the world's most widely used smartphone operating system until 2010 with a peak market share of 74% in 2006. In 1996, [[Palm, Inc.#Founding and acquisition|Palm Computing]] released the [[Pilot 1000]] and Pilot 5000, running [[Palm OS]]. Microsoft [[Windows Embedded Compact|Windows CE]] was the base for Pocket PC 2000, renamed [[Windows Mobile]] in 2003, which at its peak in 2007 was the most common operating system for smartphones in the U.S.

In 2007, Apple introduced the [[iPhone]] and its operating system, known as simply [[IPhone OS 1|iPhone OS]] (until the release of [[iOS 4]]), which, like [[macOS|Mac OS X]], is based on the [[Unix-like]] [[Darwin (operating system)|Darwin]]. In addition to these underpinnings, it also introduced a powerful and innovative graphic user interface that was later also used on the [[tablet computer]] [[iPad]]. A year later, [[Android (operating system)|Android]], with its own graphical user interface, was introduced, based on a modified [[Linux kernel]], and [[Microsoft]] re-entered the mobile operating system market with [[Windows Phone]] in 2010, which was replaced by [[Windows 10 Mobile]] in 2015.

In addition to these, a wide range of other [[mobile operating system]]s are contending in this area.