MS-DOS (short for Microsoft Disk Operating System) is an operating system commercialized by Microsoft. See also X86 assembly language The generic term x86 refers to the most commercially successful Instruction set architecture in the history of Personal In Computer science, the kernel is the central component of most computer Operating systems (OS A monolithic kernel is a kernel architecture where the entire kernel is run in Kernel space in Supervisor mode. The user interface (or Human Computer Interface) is the aggregate of means by which people&mdash the users '&mdash interact with the System TUI short for Text User Interface or Textual User Interface (and sometimes Terminal User Interface) is a Retronym that was coined sometime A software license (or software licence in commonwealth usage is a Legal instrument governing the usage or redistribution of copyright protected software Proprietary software is Computer software on which the producer has set restrictions on use private modification copying, or republishing. An operating system (commonly abbreviated OS and O/S) is the software component of a Computer system that is responsible for the management and coordination Microsoft Corporation is an American multinational Computer technology Corporation, which rose to dominate the Home computer It was the most commonly used member of the DOS family of operating systems and was the dominant operating system for computers based on the Intel 8086 family of microprocessors, particularly the IBM PC and compatibles, during the 1980s. DOS, short for "Disk Operating System" is a shorthand term for several closely related Operating systems that dominated the IBM PC compatible market The 8086 is a 16-bit Microprocessor chip designed by Intel and introduced on the market in 1978 which gave rise to the X86 architecture IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. It was gradually replaced on consumer desktop computers by operating systems offering a graphical user interface (GUI), in particular by various generations of the Microsoft Windows operating system. Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. It was originally known as QDOS (Quick and Dirty Operating System) and 86-DOS. 86-DOS was an operating system developed and marketed by Seattle Computer Products for its Intel 8086 -based computer kit 86-DOS was an operating system developed and marketed by Seattle Computer Products for its Intel 8086 -based computer kit 
MS-DOS was originally released in 1981 and had eight major versions released before Microsoft stopped development in 2000. It was the key product in Microsoft's growth from a programming languages company to a diverse software development firm, providing the company with essential revenue and marketing resources. A programming language is an Artificial language that can be used to write programs which control the behavior of a machine particularly a Computer. It was also the underlying basic operating system on which early versions of Windows ran as a GUI.
MS-DOS was a renamed form of 86-DOS by Seattle Computer Products. DOS, short for "Disk Operating System" is a shorthand term for several closely related Operating systems that dominated the IBM PC compatible market 86-DOS was an operating system developed and marketed by Seattle Computer Products for its Intel 8086 -based computer kit Seattle Computer Products (SCP was a Seattle Washington computer hardware company which was one of the first manufacturers of Computer systems based on the Intel It began as an operating system for the then-new Intel 8086. The 8086 is a 16-bit Microprocessor chip designed by Intel and introduced on the market in 1978 which gave rise to the X86 architecture Originally MS-DOS was designed to be an operating system that could run on any 8086-family computer. Each computer would have its own distinct hardware and its own version of MS-DOS; programs would make standard calls to the operating system, and each version of MS-DOS would translate these calls into the necessary commands to send to the hardware. Software would be written for the operating system, not the computer. However, to make their programs run faster, developers often violated the concept of accessing hardware through the operating system. The greater speed attainable by direct control of hardware was of particular importance when running computer games. A personal computer Game (also known as a computer game or simply PC game) is a Video game played on a Personal computer, rather IBM-compatible architecture then became the goal. Soon all 8086-family computers closely emulated IBM's hardware, and a single version of MS-DOS was all that was needed for the market.
While MS-DOS appeared on PC clones, true IBM computers used PC-DOS, a rebranded form of MS-DOS. IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. IBM PC-DOS is a DOS operating system for the IBM Personal Computer, sold throughout the 1980s and 1990s
Incidentally, the dependence on IBM-compatible hardware caused major problems for the computer industry when the original design had to be changed. For example, the original design could support no more than 640 kilobytes of memory. Manufacturers had to develop complicated schemes to access additional memory. This would not have been a limitation if the original idea of interfacing with hardware through MS-DOS had endured.
On microcomputers based on the Intel 8086 and 8088 processors—including but by no means restricted to the IBM PC (and clones) architecture—the initial competition to the PC-DOS/MS-DOS line came from Digital Research, whose CP/M operating system had inspired MS-DOS. Digital Research Inc (aka DR or DRI; originally Intergalactic Digital Research) was the company created by Dr CP/M (Control Program for Microcomputers is an Operating system originally created for Intel 8080 / 85 based Microcomputers by Gary Kildall Digital Research released CP/M-86 a few months after MS-DOS, and it was offered as an alternative to MS-DOS and Microsoft's licensing requirements, but at a higher price. CP/M-86 was a version of the CP/M operating system that Digital Research made for the Intel 8086 and Intel 8088. Executable programs for CP/M-86 and MS-DOS were not interchangeable with each other; much applications software was sold in both MS-DOS and CP/M-86 versions until MS-DOS became preponderant (later Digital Research operating systems could run both MS-DOS and CP/M-86 software). In Computing, an executable (file causes a computer "to perform indicated tasks according to encoded instructions," as opposed to a file that only contains Application software is a subclass of Computer software that employs the capabilities of a computer directly and thoroughly to a task that the user wishes to perform MS-DOS supported the simple .COM and the more advanced relocatable .EXE executable file formats; CP/M-86 a relocatable format using the file extension .CMD. EXE is the common Filename extension denoting an Executable file (a program) in the DOS, OpenVMS, Microsoft Windows, A filename extension is a suffix to the name of a Computer file applied to indicate the encoding convention ( File format) of its contents In CP/M-86, CMD is the Filename extension used by Executable programs
In the later days of MS-DOS, once the IBM-compatible platform was chosen, one would buy any PC clone, get any copy of MS-DOS (or IBM-branded MS-DOS, i. e. , PC-DOS)—done. Many people do not realise that in the early days one chose an IBM PC, or a Sirius, or Apricot, or other make; these machines all had different architecture and did not even accept the same expansion cards; many of them were not limited to a maximum of 640 kilobytes of system memory, unlike the PC and clones. Then the decision whether to use MS-DOS or CP/M-86 had to be taken, and the appropriate one had to be acquired from the computer manufacturer; it was not possible to use versions of MS-DOS, or PC-DOS, interchangeably. One was then tied to using software for the operating system chosen (or, funds permitting, having floppy disks for both, and booting the appropriate one).
In the business world the 808x-based machines that MS-DOS was tied to faced competition from the Unix operating system which ran on many different hardware architectures. Unix (officially trademarked as UNIX, sometimes also written as Unix with Small caps) is a computer Microsoft themselves sold a version of Unix for the PC called Xenix. Xenix is a version of the Unix Operating system, licensed by Microsoft from AT&T in the late 1970s
In the emerging world of home users, a variety of other computers based on various other processors were in serious competition with the IBM PC: the Apple II, early Apple Macintosh, the Commodore 64 and others did not use the 808x processor; many 808x machines of different architectures used custom versions of MS-DOS. Macintosh, commonly nicknamed Mac is a Brand name which covers several lines of Personal computers designed developed and marketed by Apple Inc At first all these machines were in competition. In time the IBM PC hardware configuration became dominant in the 808x market as software written to communicate directly with the PC hardware without using standard operating system calls ran much faster, but on true PC-compatibles only. Non-PC-compatible 808x machines were too small a market to have fast software written for them alone, and the market remained open only for IBM PCs and machines that closely imitated their architecture, all running either a single version of MS-DOS compatible only with PCs, or the equivalent IBM PC-DOS. Most clones cost much less than IBM-branded machines of similar performance, and became widely used by home users, while IBM PCs had a large share of the business computer market.
Microsoft and IBM together began what was intended as the follow-on to MS/PC-DOS, called OS/2. OS/2 is a computer Operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively When OS/2 was released in 1987, Microsoft began an advertising campaign announcing that "DOS is Dead" and stating that version 4 was the last full release.
MS-DOS had grown in spurts, with many significant features being taken (or duplicated) from other products and operating systems, as well as incorporating the functionality of tools and utilities developed by independent companies to improve the functionality of MS-DOS, including Norton Utilities, PC Tools (Microsoft Anti-Virus), QEMM expanded memory manager, DOS/4GW (a 32-bit DOS extender), Stacker disk compression, and others. The Norton Utilities releases were collections of Software utilities PC Tools was a collection of Software utilities from Central Point Software. Microsoft Anti-Virus ( MSAV) was an antivirus program introduced by Microsoft for its Quarterdeck Expanded Memory Manager (abbreviated QEMM sometimes pronounced ˈkwɛm though not by those who developed it is a Memory manager produced by Quarterdeck Office DOS/4GW is a 32-bit DOS extender that allows DOS programs to eliminate the 640 KB Conventional memory limit by addressing up to 32 The range of Integer values that can be stored in 32 bits is 0 through 4294967295 or −2147483648 through 2147483647 using Two's complement encoding Developed in the 1980s to cope with the memory limitations of MS-DOS and its derivatives DOS extenders are programs which enable software to run under the Protected mode Stac Electronics was an Engineering company founded in 1983 by seven friends at Caltech. OS/2 was designed for efficient multitasking—an IBM speciality derived from deep experience with mainframe operating systems—and offered a number of advanced features that had been designed together with similar look and feel; it was seen as the legitimate heir to the "kludgy" DOS platform. Look and feel is a term used in descriptions of products and fields such as Marketing, Branding and Trademarking to signify the experience a person has using
During the period when Digital Research was competing in the operating system market some computers, like Amstrad PC-1512, were sold with floppy disks for two operating systems (only one of which could be used at a time), MS-DOS and CP-M86 or a derivative of it. The Amstrad PC1512 was Amstrad 's mostly IBM PC -compatible Home computer system first manufactured in 1986 Digital Research produced DOS Plus, which was compatible with MS-DOS 2. DOS Plus (also known as DOS+ is an operating system written by Digital Research, first released in 1985 11, supported CP/M-86 programs, had additional features including multi-tasking, and could read and write disks in CP/M and MS-DOS format.
While OS/2 was under protracted development, Digital Research released the MS-DOS compatible DR-DOS 5, which included features only available as third-party add-ons for MS-DOS (and still maintained considerable internal CP/M-86 compatibility). DR-DOS is a DOS -type Operating system for IBM PC - compatible Personal computers, originally developed by Gary Kildall Unwilling to lose any portion of the market, Microsoft responded by announcing the "pending" release of MS-DOS 5. 0 in May 1990. This effectively killed most DR-DOS sales until the actual release of MS-DOS 5. 0 in June 1991. Digital Research brought out DR-DOS 6, which sold well until the "pre-announcement" of MS-DOS 6. 0 again stifled the sales of DR-DOS.
Microsoft has been accused of carefully orchestrating leaks about future versions of MS-DOS in an attempt to create what in the industry is called FUD (fear, uncertainty, and doubt) regarding DR-DOS. For example, in October 1990, shortly after the release of DR-DOS 5. 0, and long before the eventual June 1991 release of MS-DOS 5. 0, stories on feature enhancements in MS-DOS started to appear in InfoWorld and PC Week. Brad Silverberg, Vice President of Systems Software at Microsoft and General Manager of its Windows and MS-DOS Business Unit, wrote a forceful letter to PC Week (November 5, 1990), denying that Microsoft was engaged in FUD tactics ("to serve our customers better, we decided to be more forthcoming about version 5. 0") and denying that Microsoft copied features from DR-DOS:
"The feature enhancements of MS-DOS version 5. 0 were decided and development was begun long before we heard about DR-DOS 5. 0. There will be some similar features. With 50 million MS-DOS users, it shouldn't be surprising that DRI has heard some of the same requests from customers that we have. " – (Schulman et al. 1994). Year 1994 ( MCMXCIV) was a Common year starting on Saturday (link will display full 1994 Gregorian calendar) 
The pact between Microsoft and IBM to promote OS/2 began to fall apart in 1990 when Windows 3.0 became a marketplace success. Windows 30 is the third major release of Microsoft Windows, and came out on 22 May 1990 Much of Microsoft's further contributions to OS/2 also went in to creating a third GUI replacement for DOS, Windows NT. Windows NT is a family of Operating systems produced by Microsoft, the first version of which was released in July 1993
IBM, which had already been developing the next version of OS/2, carried on development of the platform without Microsoft and sold it as the alternative to DOS and Windows.
MS-DOS has effectively ceased to exist as a platform for desktop computing. Since the releases of Windows 9x, it was integrated as a full product mostly used for bootstrapping, and no longer officially released as a standalone DOS, although at first DOS 7 (which was the DOS part included in Windows 95) had been developed as a standalone OS. Windows 9x is the family of Microsoft Windows Operating systems that comprises the hybrid 16/32-bit Windows versions Windows 95, Windows 98 In computing bootstrapping ("to pull oneself up by one's bootstraps" refers to techniques that allow a simple system to activate a more complicated system It was still available, but became increasingly irrelevant as development shifted to the Windows API. The Windows API, informally WinAPI, is Microsoft's core set of Application programming interfaces (APIs available in the Microsoft Windows Operating
Windows XP contains a copy of the core MS-DOS 8 files from Windows Millennium, accessible only by formatting a floppy as an "MS-DOS startup disk". Attempting to run
COMMAND. COM from such a disk under the NTVDM results in the message "Incorrect MS-DOS version". (Note that the DOS boot disk created by Windows XP is even more stripped-down than that created in Windows 98, as it does not include CD-ROM support. )
With Windows Vista the files on the startup disk are dated 18th April 2005 but are otherwise unchanged, including the string "MS-DOS Version 8 (C) Copyright 1981-1999 Microsoft Corp" inside
Today, DOS is still used in embedded x86 systems due to its simple architecture, and minimal memory and processor requirements. The command line interpreter of NT-based versions of Windows, cmd.exe, maintains most of the same commands and some compatibility with DOS batch files. Windows NT is a family of Operating systems produced by Microsoft, the first version of which was released in July 1993 cmdexe is the Command line interpreter on OS/2, Windows CE and on Windows NT -based operating systems (including Windows
As a response to Digital Research's DR-DOS 6. Digital Research Inc (aka DR or DRI; originally Intergalactic Digital Research) was the company created by Dr DR-DOS is a DOS -type Operating system for IBM PC - compatible Personal computers, originally developed by Gary Kildall 0, which bundled SuperStor disk compression, Microsoft opened negotiations with Stac Electronics, vendor of the most popular DOS disk compression tool, Stacker. Stac Electronics was an Engineering company founded in 1983 by seven friends at Caltech. In the due diligence process, Stac engineers had shown Microsoft some Stacker source code. Due Diligence is a term used for a number of concepts involving either the performance of an investigation of a business or person or the performance of an act with a certain Standard Stac was unwilling to meet Microsoft's terms for licensing Stacker and withdrew from the negotiations. Microsoft chose to license Vertisoft's DoubleDisk, using it as the core for its DoubleSpace disk compression. 
MS-DOS 6. 0 and 6. 20 were released in 1993, both including the Microsoft DoubleSpace disk compression utility program. Stac successfully sued Microsoft for patent infringement regarding the compression algorithm used in DoubleSpace. A patent is a set of Exclusive rights granted by a State to an inventor or his assignee for a fixed period of time in exchange for a disclosure of an This resulted in the 1994 release of MS-DOS 6. 21, which had disk-compression removed. Shortly afterwards came version 6. 22, with a new version of the disk compression system, DriveSpace, which had a different compression algorithm to avoid the infringing code.
Prior to 1995, Microsoft licensed MS-DOS (and Windows) to computer manufacturers under three types of agreement: per-processor (a fee for each system the company sold), per-system (a fee for each system of a particular model), or per-copy (a fee for each copy of MS-DOS installed). The largest manufacturers used the per-processor arrangement, which had the lowest fee. This arrangement made it expensive for the large manufacturers to migrate to any other operating system, such as DR-DOS. In 1991 the US government Federal Trade Commission began investigating Microsoft's licensing procedures resulting in a 1994 settlement agreement limiting Microsoft to per-copy licensing. Year 1991 ( MCMXCI) was a Common year starting on Tuesday (link will display full calendar of the Gregorian Calendar. The Federal Trade Commission ( FTC) is an independent agency of the United States government, established in 1914 by the Federal Trade Commission Act Digital Research did not gain by this settlement, and years later its successor in interest Caldera sued Microsoft for damages. The SCO Group Inc ( TSG, informally SCO;) is a software company formerly called Caldera Systems and Caldera International. This lawsuit was settled with a monetary payment of 150 million dollars.
Microsoft also used a variety of tactics in MS-DOS and several of their applications and development tools that, while operating perfectly when running on genuine MS-DOS (and PC-DOS), would break when run on another vendor's implementation of DOS. Notable examples of this practice included:
All versions of Microsoft Windows have had an MS-DOS like command-line interface (CLI). Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. Versions of Windows (up to 3. 11) ran as a GUI running under MS-DOS. Windows 95 and 98 had an MS-DOS prompt which behaved very much like MS-DOS, with added facilities for such things as long file names.
The true 32-bit versions of Windows, from Windows NT, are not based on DOS but provide a command-line interface similar to MS-DOS's character-mode interface. This command line is provided by a native executable,
cmd. exe. Many command-line applications (known as console applications) for Windows are incorrectly referred to as DOS applications, although they are actually Windows applications, supporting Windows system calls, which use the text console for input and output rather than a graphical interface. Both true MS-DOS programs and programs written for the Windows CLI but incompatible with MS-DOS can be run from the command line.
32-bit Windows can run MS-DOS programs through the use of the NTVDM (NT Virtual DOS Machine), and the 16-bit
command. Virtual DOS machine (VDM is Microsoft 's technology that allows running legacy MS-DOS and 16-bit Windows programs on Intel 80386 or higher computers com interpreter from MS-DOS 5. 0 is still included to maintain application compatibility with programs that expect it (see the output produced by the command "
command. com /k ver", which displays "
MS-DOS Version 5. 00. 500" in the console window). The command "
ver" returns the string "
Microsoft(R) Windows DOS" when executed under
command. com, but "
Microsoft Windows XP [Version 5. 1. 2600]" (or similar depending on the version of 32-bit Windows) when run from
Recent versions of Windows for x64 architectures, including Windows XP Professional x64 Edition, Windows Server 2003 x64 and Windows Vista x64, no longer include the NTVDM and can therefore no longer natively run MS-DOS or 16-bit Windows applications. Windows XP has been released in several editions since its original release in 2001 Windows Server 2003 (also referred to as Win2K3 is a server Operating system produced by Microsoft. Windows Vista (ˈvɪstə is a line of Operating systems developed by Microsoft for use on Personal computers including home and business desktops For MS-DOS and Windows 3. 11 or earlier programs, however, there exist alternatives in the form of emulators such as Microsoft's own Virtual PC, Bochs, DOSBox, etc. Microsoft Virtual PC is a Virtualization suite for Microsoft Windows Operating systems and an Emulation suite for Bochs is a portable X86 and AMD64 PC Emulator and Debugger mostly written in C++ and distributed as Free software DOSBox is an Emulator which simulates a computer running MS-DOS.
From 1983 onwards, various companies have worked on graphical user interfaces (GUIs) capable of running on PC hardware. With DOS being the dominant operating system several companies released alternate shells, e. g. Microsoft Word for DOS, XTree, and the Norton Shell. XTree is File manager Software originally designed for use under DOS. However, this required duplication of effort and did not provide much consistency in interface design (even between products from the same company).
Later, in 1985, Microsoft Windows was released as Microsoft's first attempt at providing a consistent user interface (for applications). Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. The early versions of Windows ran on top of MS-DOS and its clones. At first Windows met with little success, but this was also true for most other companies' efforts as well, for example GEM. GEM ( G raphical E nvironment M anager was a Windowing system created by Digital Research Inc After version 3. 0 (1990), Windows gained marked acceptance.
Later versions (Windows 95, Windows 98 and Windows Me) used the DOS boot process to launch itself into protected mode. Basic features related to the file system, such as long file names, were only available to DOS when running as a subsystem of Windows. Windows NT ran independently of DOS but included a DOS subsystem so applications could run in a virtual machine under the new OS. Windows NT is a family of Operating systems produced by Microsoft, the first version of which was released in July 1993 In Computer science, a virtual machine (VM is a Software implementation of a machine (computer that executes programs like a real machine With the latest Windows releases, even dual-booting MS-DOS is problematic as DOS may not be able to read the basic file system.
Several similar products were produced by other companies. In the case of PC-DOS and DR-DOS, it is common but incorrect to call these "clones". DR-DOS is a DOS -type Operating system for IBM PC - compatible Personal computers, originally developed by Gary Kildall Given that Microsoft manufactured PC-DOS for IBM, PC-DOS and MS-DOS were (to continue the genetic analogy) "identical twins" that diverged only in adulthood and eventually became quite different products; DR-DOS was a clone of itself once removed.
These products are collectively referred to as DOS. IBM PC-DOS is a DOS operating system for the IBM Personal Computer, sold throughout the 1980s and 1990s DR-DOS is a DOS -type Operating system for IBM PC - compatible Personal computers, originally developed by Gary Kildall DR-DOS is a DOS -type Operating system for IBM PC - compatible Personal computers, originally developed by Gary Kildall OpenDOS is a Freeware DOS -like and MS-DOS -compatible Operating system. FreeDOS (formerly Free-DOS and PD-DOS) is an Operating system for IBM PC compatible computers PTS-DOS is a Disk operating system, a DOS clone developed in Russia by PhysTechSoft. DOSBox is an Emulator which simulates a computer running MS-DOS. However, MS-DOS can be a generic reference to DOS on IBM-PC compatible computers.
Several multiuser operating systems capable of running MS-DOS software, and also purpose-written software with multiuser enhancements such as record locking for multiuser databases, have been produced.
"IBM wanted CP/M prompts. Multiuser DOS is a soft real-time Operating system for IBM PC -compatible microcomputers Multiuser DOS is a soft real-time Operating system for IBM PC -compatible microcomputers PC-MOS/386 was a Multi-user, multi-tasking operating system produced by The Software Link. This article details various versions of DOS -compatible operating systems This is a listing of the versions of the operating systems offered by Microsoft as Windows. A partial list of the most common commands for Microsoft 's MS-DOS Operating system follows Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. In 1983 Microsoft announced the development of Windows, a Graphical user interface (GUI for its own Operating system ( MS-DOS) that had shipped "Bad command or file name" is a common Error message in Microsoft 's MS-DOS and some other operating systems DOSKey is a utility for MS-DOS and Microsoft Windows that adds Command history, macro functionality and improved editing features to the Win32 console is a Plain text window for Console applications within the system of Windows API. The MS-DOS API is an API used originally in MS-DOS / PC-DOS, and later by other DOS systems CP/M (Control Program for Microcomputers is an Operating system originally created for Intel 8080 / 85 based Microcomputers by Gary Kildall It made me throw up. " -- Tim Paterson