DOS for IBM PC compatibles

Particularly, DOS refers to a personal of closely related operating systems which dominated the IBM PC compatible market for the decade between 1985 and 1995: PC-DOS, MS-DOS, DR-DOS, FreeDOS, OpenDOS, PTS-DOS, and many others. One, MS-DOS from either Microsoft became the virtually all widely utilized.

MS-DOS (& a IBM PC-DOS which was licensed therefrom), & its predecessor, QDOS, was a successor to CP/M (Command Processor / (for) Kicrocomputers)—which was a dominant operating technique for Ogdoad-bit Intel 8080 and Zilog Z80 based microcomputers.

DOS was one of a foremost operating systems for the PC compatible platform, & a 1st thereon platform to benefit far flung utilise (it was however far flung supplementary than Ten years late). This was a test2 & mussy affair (the variant MS-DOS, every now and again conversationally known as Messy DOS, was developed from either QDOS, which literally meant "Quick and Dirty Operating System").

IBM-PCs were only distributed using PC-DOS, whereas PC compatible computers from 100% more manufacturers were distributed by owning MS-DOS. For the early years of this operating formulas personal, PC-DOS was nearly monovular to MS-DOS. Extra recently, loose versions of DOS such as FreeDOS and OpenDOS have started to pop up.

Early versions of Microsoft Windows were little more than the in writing shell for DOS, and late versions of Windows were tightly integrated by having MS-DOS. These are besides imaginable to do DOS software under OS/2 and Linux using virtual-machine emulators.

Because of a hanker being & omnipresence of DOS in the globe of the PC-compatible platform (DOS compatible computer software were processed swell into the Ninety's), DOS was typically considered to exist as a native operating system of the PC compatible platform.

Accessing hardware under DOS

the operating patterns offered a hardware abstraction layer that although adequate for developing character-depending applications was sadly short for accessing virtually all of the hardware (such as a graphics devices). This led to application computer programmer accessing a devices directly. A symptom of this was that for each one application would develop to have a placed of device drivers written for it to use a various types of devices in offer (different printers, etc.), and while a few fresh devices was freed, a devices manufacturers would use to make a point that driver for their devices for the popular applications became available.

DOS and other PC operating systems

Early versions of Microsoft Windows were "shell-type" software online that ran under DOS. Late versions were launched under DOS however "extended" it by running into secure mode. However late versions of MS Windows ran independently of DOS however involved good deal of the old code such that it can redo inside virtual machines under a recently OS & the latest versions of MS Windows come high-pressure dropping ever supplementary of the DOS ancestry. Windows Me was the previous Microsoft OS to begin in DOS.

Under Linux (running in x86-based systems) it's conceivable to redo copies of DOS & numerous of its clones under dosemu (a Linux native virtual machine program for running off real mode programs). There are the total of more ape for going DOS and/or DOS-depending computer software under various versions of UNIX, potentially in non-x86 platforms; 1 such ape is DOSBox.

Understand as well: List of DOS commands

Reserved device names under DOS

There are reserved device list inside DOS that can't exist when utilized as filenames irrespective of extension; these restrictions as well affect many Windows versions, within occasionally shells stimulating crashes & security vulnerabilities.

The unfair listing one reticent list is: AUX (Auxillary equipment), COM, COM0, COM1, COM2, COM3, ..., COM8, COM9 (Everthing COM ports), CON (Console I/O), LPT1, LPT2, NUL, & PRN.

Drive naming scheme
Under Microsoft's DOS operating system and its derivatives drives come referred to by identifying letters. Standard practice is to reserve "A" & "B" for floppy causes. In systems by having sole of these floppy caapply DOS permitted a use of two letters for 1 cause, & displayed prompts to swap disks. This allowed for copying from either diskette to floppy disk (this wasn't the in no time method though when it typically ended higher request for even disk barter far other typically than really requisite) or getting the program redo from either of these floppy disk when getting its informatiin on an additional. Disk drive were originally assigned a letters "C"& "D", however when trend lines for extra disk drive became available this developed into assigning a primary partitions on both cause (DOS exclusively allowed one active primary partition by a cause possibly though a partitioning body allow other) letters number one, so making another skip the causes to allocate letters to logical causes in the extended partitions. Letters for CD-ROMs, RAM disks and other items were allocated when a disk drive partitions. This was typically done just in a sequentially the drivers were loaded, although several drivers can be specifically instructed to take a different letter. Network causes were commonly given letters lot farther in in a alphabet per network driver computer software and so that it were typically away from the way of this models.

Because these letters were utilized directly by normal applications (unlike a /dev/* list within unix-like operating systems), the addition of even more, an extra disk drive can be turbulent to applications, which so involved reconfiguration or reinstallation. This wwhen especially confessedly around case there were logical causes in a long partition on a original disc cause & the freshly disk drive experienced a primary partition, as it would so induce the logical causes on the number 1 arduous drive to vary letters. But, potentially whenever a recently disk drive got exclusively logical causes around a long partition it would however disrupt a letters of RAM disks and CD-ROM drives. This troubled body persisted through the 9x versions of Windows however NT adopts the slightly different models. It utilizes a traditional system once number 1 installing however fallowing that it seeks to preserve a letters of existing causes.

DOS for other computers

Before (& to a few extent at a same time by owning) the development of the IBM PC compatible personal of personal computer, many more operating systems for more architectures were already referred to as DOS, notably:

The DOS initial/simple operating body for the IBM System/360 family of mainframe computers (it later became DOS/VSE, & was finally good known as VSE). The DOS operating formulas for DEC PDP-11 minicomputers (this OS & a computers it ran in were about obsolete per period PCs became green, by using various descendent and more replacements). The DOS operating body for the Apple Computer's Apple II family of computers. This was a primary operating rules for this personal from either 1979 by having a introduction of the floppy disk drive until 1983 with a introduction of ProDOS; many population continued utilizing it hanker when that date. Ordinarily it was known as Apple DOS to distinguish it from MS-DOS. Commodore DOS, which was used by Eighter from decatur-bit Commodore computers. Unlike virtually all more DOS systems, it was integrated into a disk causes, non loaded into a computer's have memory. Atari DOS, which was used per Atari 8-bit family of computers. A Atari OS sole offered on line-subordinate disk-access, and so an additional layer known as DOS was booted hit of the floppy disk that offered higher level functions like filesystems.