Microsoft's disk operating system, MS-DOS was the dominant operating system for the PC compatible platform during the 1980s. It has bit by bit been replaced in consumer desktop computers by owning various generations of the Windows operating system.

MS-DOS was originally freed around 1981 and had eight major versions freed prior to Microsoft stopped development around 2000. It was a key product around Microsoft's incubation from either the programming languages company to a diverse software package development business firm, providing a company using essential revenue & marketing resources.

History
MS-DOS was created by computer manufacturer Seattle Computer Products (SCP) in 1980 as QDOS (for Quick & Contaminated Operating Rules), however was renamed 86-DOS because it was designed to begin on the Intel 8086 processor. Around the sequence of cases that would later in inspire good deal folklore, Microsoft licensed QDOS to IBM on behalf of SCP. Microsoft acquired a models for merely $50,000 from either SCP shortly prior to a PC's release.

Development

IBM and Microsoft both released versions of DOS; a IBM version was furnished with the IBM PC and known as PC-DOS. Originally, IBM just validated & packaged Microsoft developments, & so IBM's versions tended to become freed shortly when Microsoft's. Notwithstanding, MS-DOS Four.Cipher was actually according to IBM PC-DOS Four.Cipher, when Microsoft was by so concentrating in OS/2 development. Microsoft freed its versions under a title "MS-DOS", when IBM freed its versions under a title "PC DOS". Ab initio, once Microsoft would license their OEM version of MS-DOS, a computer manufacturer would customize its title (we.e. TandyDOS, Compaq DOS, etc). Virtually all one versions were monovular to a official MS-DOS; yet, Microsoft began to insist that OEMs begin calling the product MS-DOS. Yet, single IBM resisted this move.

Computer advert of this time period typically claimed that computers were "IBM-Compatible" & super seldom "MS-DOS compatible". Them terms are non equivalent word. There were computers which utilized MS-DOS which may not redo all the software package that an IBM-Compatible machine may. An case is the Pivot, which utilized MS-DOS however was non IBM-Compatible. Computer program would indeed dog sooner in case it were written to IBM standards, by bypassing a lot slower MS-DOS functions for, for instance, sending tools to the screen. An IBM-Compatible machine would send streaming videos references directly to the locality of memory assigned to that, which was non section of the MS-DOS specifications.

PC DOS One.0 - August 1981 - Initial release with a number one IBM-PC PC DOS One.One - May 1982 MS-DOS One.25 - Will 1982 - Foremost release for non-IBM hardware MS-DOS Two.0 - March 1983 - Introduced features from Unix like subdirectories, manage-depending file operations, comm& input/output redirection, and pipes. Microsoft decided to apply backslashes equally pathname extractor like than slashes when in Unix apparently due to a latter character existence utilized as the switch character in virtually all DOS & CP/M programs. Adds trend lines for winchester drive & 360KB floppy disks PC DOS Two.One - October 1983 MS-DOS Deuce.11 - March 1984 MS-DOS Three.0 - August 1984 - Adds trend lines for One.2MB floppy disks & big tough disks MS-DOS Trine.One - November 1984 MS-DOS Three.Two - January 1986 - Supported 2 arduous disk partitions of as much as 32MB, 1 primary & 1 "logical drive" around an "extended partition" PC DOS Trio.Three - April 1987 MS-DOS Three.Three - August 1987 - Supported multiple logical drives MS-DOS Four.0 - June 1988 - ''actually derived from IBM's codebase like than a reverse PC DOS Four.0 - July 1988 - added the DOS Scale, the graphic menu selector, & support for hard disks of >32MB using the format from Compaq DOS 3.31. As well added several bugs & offered less loose conventional memory than prior to. Typically regarded as an abortive release & to become avoided MS-DOS Four.01 - November 1988 - bug-fix release MS-DOS Five.0 - June 1991 - In response to DR-DOS 5.0, adds like features to it product: memory management, good-screen editor, QBasic programing language, on the net aid, & DOS Plate profits project switcher. Look at DR-DOS article for more information MS-DOS Hexad.0 - March 1993 - Response to DR-DOS 6.Cipher. Added DoubleSpace disk compression (traced from either Stacker) & more features MS-DOS 6.Two - November 1993 - Bug fix release MS-DOS 6.21 - February, 1994 - Following Stac suit, flushed DoubleSpace disk compression PC DOS Sise.Three - April 1994 MS-DOS 6.22 - June 1994 - Survive official have-alone version. DoubleSpace replaced sustaining non-infringing however compatible DriveSpace tool PC DOS 7.0 - April,1995 - Bundles Stacker in place of DriveSpace MS-DOS 7.0 - August 1995 - Shipped embedded inside Windows 95. Involved big disk (LBA) & Long File Title (LFN) support MS-DOS 7.One - August 1996 - Shipped embedded in Windows 95B (OSR2) (& Windows 98 in June 1998). Added trend lines for FAT32 file system MS-DOS 8.0 - September 2000 - Shipped embedded in Windows ME. Endure version of MS-DOS. Removes SYS comm&, ability additionally to command line and more features PC DOS 2000 - Season 2000-compliant version using minor extra features. Final member of the MS-DOS family

Source: [http://members.fortunecity.com/pcmuseum/dos.htm PC Museum]''

MS-DOS grew within spirt, by owning several important features existence taken from either more products & operating systems, like Microsoft's have Xenix - a variant in Unix - and Digital Research's DR-DOS, when well as information & utilities including Norton Utilities, PC Tools (Microsoft Anti-Virus), QEMM expanded memory manager, Stacker disk compressiin, and so on.

Using Intel's introduction of the 80286 microprocessor, IBM and Microsoft began functiin on the joint task known as OS/2, originally a protected-mode version of MS-DOS. Late, Microsoft abandoned a task to devote fully resources to Windows and Windows NT. Digital Research created the GEM graphical user interface (GUI), which had little popularity in PC compatibles. It was super successful on the Atari ST machines, but was at long last eclipsed by Microsoft's Windows Three.Zero release.

Although its role as a desktop computer operating models has greatly diminished, inside todays world these are however utilized in various embedded x86 systems due to its simplistic architecture, minimum memory requirements, & minimum processor speed requirements.

Legal issues

As a response to Digital Research's DR-DOS 6.0, which bundled SuperStor disk compression, Microsoft opened negotiations by having Stac Electronics, vendor of the virtually all popular DOS disk compression thing, Stacker. Stac was unwilling to meet Microsoft's terms for licensing Stacker & withdrew from either a negotiations. In the due diligence process, Stac engineers had shown Microsoft a select few Stacker source code.

Soon, MS-DOS Sixer.Nought was freed, including a Microsoft DoubleSpace disk compression utility. Stac with success sued Microsoft for patent infringement regarding a compression algorithmic program utilized around DoubleSpace. This resulted in the release of MS-DOS 6.Xxi, which experienced disk-compression flushed. Shortly after come version Vi.Twenty-two, by using a newly version of the disk compression body, DriveSpace, rewritten to stay away from the infringing code.

These maneuver were green for Microsoft; a company wasted a second case ensuant from either code inside Windows Three.Single which stimulated spurious errors whilst Windows was launched in DR-DOS. View a DR-DOS article for more on this & Embrace, extend and extinguish for more in Microsoft's perceived anti-competitive maneuvers.

Before 1995, Microsoft licensed MS-DOS to computer manufacturers under ternion types of agreement: by the-processor even (the fee for both formulas the company sold), by the-body (the fee for both patterns of the particular model), or by the-copy (a fee for both copy of MS-DOS installed). A big manufacturers utilized a by a-processor arrangement, which got the last-place fee. This arrangement manufactured it expensive for the big manufacturers to migrate to any more operating formulas, like DR-DOS. Inside 1994 a U.s. government charged Microsoft by having violations of antitrust law, and the cash settlement agreement limited Microsoft to by the-rules licensing. Digital Locate did non benefit by this class action settlement, & years late its successor around interest Caldera sued Microsoft for damages. This causthe was settled by owning a pecuniary payment of 150 million dollars.

Multitasking

MS-DOS was non designed to become the multi-user or even multitasking operating system, however numbers of tries were manufactured to retrofit these capabilities. A Terminate and Stay Resident (TSR) system call (originally targeted at loadable device drivers) and more mostly-undocumented functions were utilized to produce pop-up applications. Although it used a two itself, Microsoft discouraged utilise & every now and again denied the being one undocumented functions, however when numerous classes of co-resident computer software needed these features developers were forced to disassemble MS-DOS to produce their products. Borland's SideKick personal productivity product was a notable specimen. Add-in environments prefer TopView and especially DESQview attempted to provide multitasking, and achieved a select few profits once late combined sustaining a virtual 8086 mode and virtual memory features of the Intel 80386 and later processors. Windows/386 2.1 and subsequent versions provided similar albeit poorer features when running in "386 enhanced" mode, but Microsoft never specifically marketed this possibility and was mostly interested in converting customers to using GUI-mode Windows applications.

User interface

MS-DOS employs the command line interface and a batch scripting facility via its command interpreter, command.com. MS-DOS was designed and then users may well substitute the different command line interpreter, for example 4DOS.

Beginning using version Tetrad.Cypher, MSDOS involved the file manager program with a quasi-graphical interface (the DOS Shell) that featured menus, split windows, and program cutoff applying character mode graphics that were the primitive imitation of the Mac OS and Windows.

MS-DOS compatibility with other Microsoft operating systems

When a release of the Apple Macintosh in 1984, IBM personal computer users as well desired the graphical user interface. Several computer software going under MS-DOS tried to fill a void by creating their have graphic interface, like Microsoft Word for DOS, XTree, and a Norton Husk. But, this compulsory duplication of effort & did non provide great deal consistency around interface project (potentially between line of business).

Early versions of Microsoft Windows were ordinary computer program that ran in top of MS-DOS & its clones. Late versions were launched from either DOS however "extended" it by running into secure mode. However afterwards versions of MS Windows ran independently of DOS however involved very much of the old code such that DOS may redo within virtual machines under the newly OS. Around fresh computers, MS-DOS just can not redo directly in case a hard drive uses the NTFS file rules, which is the suggested file system around Windows XP. Users world health organization wish to access their NTFS-formatted winchester drive must have the NTFS compatible version of DOS.

Related systems

Many similar products were by more corporations. In the experience of PC-DOS & DR-DOS, it is most common however wrong to call for these "clones". Given that Microsoft made PC-DOS for IBM, PC-DOS & MS-DOS were (to prove my point a transmitted analogy) "identical twins" that diverged exclusively within adulthood & sooner or later became quite different products; DR-DOS was the clone of itself when flushed.

PC-DOS DR-DOS, Novell DOS, and OpenDOS FreeDOS, FreeDOS 32, and GNU/DOS PTS-DOS

Under Linux it is possible to redo copies of DOS & numbers of of its clones under dosemu, a Linux-native virtual machine for running real mode programs. There are the total of more emulators for running DOS under various versions of UNIX, potentially in non-x86 platforms.