MS-DOS (pronounced /ˌɛmɛsˈdɒs/ , em--dos ; short for M icro s oft D isk O perating S ystem) is an operating system bought by Microsoft. It was the most commonly used member of the DOS family of operating systems and was the main operating system for personal computers during the 1980s and 1990s. It was preceded by M-DOS (also called MIDAS), designed and copyrighted by Microsoft in 1979. MSDOS was written for the Intel 8086 family of microprocessors, particularly the IBM PC and compatibles. 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. MS-DOS developed out of QDOS ( Q uick and D irty O perating S ystem), also known as 86-DOS.
MS-DOS development originally started in 1981, and was first released in 1982 as MS-DOS 1.0. Several versions were released under different names for different hardware.
MS-DOS 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. It was also the underlying basic operating system on which early versions of Windows ran as a GUI.
History
Main article: DOSMS-DOS was a renamed form of 86-DOS (informally known as the Quick-and-Dirty Operating System or Q-DOS) owned by Seattle Computer Products, written by Tim Paterson. Microsoft needed an operating system for the then-new Intel 8086 but it had none available, so it licensed 86-DOS and released a version of it as MS-DOS 1.0. Development started in 1981, and MS-DOS 1.0 was released with the IBM PC in 1982. Tim Paterson is considered the original author of DOS and he is called "The Father of DOS".
Worried by possible legal problems, in June 1981 Microsoft made an offer to Rod Brock, the owner of Seattle Computer, to buy the rights for 86-DOS. An agreement to release all rights to the software was signed in June 1981. The total cost was $75,000.
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, similar to the situation that existed for CP/M, and with MS-DOS emulating the same solution as CP/M to adapt for different hardware platforms. So there were many different versions of "MS-DOS" for different hardware. But the greater speed attainable by direct control of hardware was of particular importance, especially when running computer games. So very soon an IBM-compatible architecture became the goal, and before long all 8086-family computers closely emulated IBM's hardware, and a only single version of MS-DOS for a fixed hardware platform was all that was needed for the market. This version is the version of MS-DOS that is discussed here, as all other versions of MS-DOS died out with their system, there were dozens of such "MS-DOS" versions.
While MS-DOS appeared on PC clones, true IBM computers used PC DOS, a rebranded form of MS-DOS. Ironically, 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.
Versions
Main article: Comparison of x86 DOS operating systemsMicrosoft licensed or released versions of MS-DOS under different names like SB-DOS or Z-DOS. Competitors released unlicensed clones such as DR-DOS and PTS-DOS.
Competition
On microcomputers based on the Intel 8086 and 8088 processors, including the IBM PC and clones, 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 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. 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). 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.
Most of the machines in the early days of MS DOS had differing system architectures and there was a certain degree of incompatibility, and subsequently vendor lock-in. Users who began using MS-DOS with their machines were compelled to continue using the version customized for their hardware, or face trying to get all of their proprietary hardware and software to work with the new system.
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. Microsoft itself sold a version of Unix for the PC called Xenix.
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. 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. 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. 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.
MS-DOS had grown in spurts, with many significant features being taken or duplicated from Microsoft's other products and operating systems. MS-DOS also grew by incorporating, by direct licensing or feature duplicating, the functionality of tools and utilities developed by independent companies, such as Norton Utilities, PC Tools (Microsoft Anti-Virus), QEMM expanded memory manager, Stacker disk compression, and others.
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. Digital Research produced DOS Plus, which was compatible with MS-DOS 2.11, 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). 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 had 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 devel
Buy Microsoft Products from Microsoft Small Business Center
Buy Microsoft Products or find a local technology consultant to help make your decision.
Buy Cheap OEM Software | Download Cheap Microsoft Office Enterprise ...
Buy Microsoft Office Product Key, there are Linux versions that are compiled and packaged and released with additional software. Buy Microsoft Office Software, the need to scan on ...
Best software catalog! All versions! buy microsoft office! Download ...
Buy Microsoft Office Accounting 2008, even amateur photographs with many flaws can be turned into high class professional product with use of photo editing software.
Download Microsoft Office Enterprise 2007! Best software! buy office ...
Buy Office 2007. CCleaner has an exceptionally powerful scan engines which ... and reliable one has to be selected for performing a registry scan, buy microsoft office 2007 product ...
Buy Microsoft Office Enterprise 2007 OEM. All software products OEM ...
Buy Microsoft Word. It gives you the opportunity to take a glimpse of your entire files without opening them.
Cheap software OEM! buy office 2007. Download Microsoft Office ...
Buy Microsoft Office 2007 Product Key, we do not want that for you of course. How about cleaning the attic and re organizing once again, buy office 2007 student edition.
OEM SOFTWARE! -90% SALE! Buy Cheap MICROSOFT OFFICE ENTERPRISE 2007 ...
Download Microsoft Windows Vista Sp2; Buy Vista Home Premium Product Key; Buy Microsoft Frontpage; Buy Vista Ultimate 64; Buy Xp Online; Buy Microsoft Word – Each time I have used any of ...
BUY MICROSOFT OFFICE ENTERPRISE 2007 - $119.90 - Buy Microsoft Word ...
Buy Microsoft Word Product Code, consumers may choose from a variety of competitive compatible Java implementations. Buy Microsoft Word 2003 Download, some of these programs will ...
Software! Oem-Box.Com! Software Catalog! buy microsoft word! Best ...
Buy Microsoft Word Product Key, here is where Registry Easy comes in. Buy Microsoft Word For Mac, you can search for thousands upon thousands of Full length DVD Quality Movies your ...
Buy Cheap OEM Software | Download Cheap Microsoft Office Enterprise ...
Buy Microsoft Office 2007 Product Key Online, accounting PortabilityMany invoice and work order packages today are not compatible with external accounting software products like ...