Dedicated to Little Pocok
MS DOS acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and some operating systems attempting to be compatible with MS-DOS, are sometimes referred to as "DOS" (which is also the generic acronym for disk operating system). MS-DOS was the main operating system for IBM PC compatible personal computers during the 1980s, from which point it was gradually superseded by operating systems offering a graphical user interface (GUI), in various generations of the graphical Microsoft Windows operating system.
IBM licensed and re-released it in 1981 as PC DOS 1.0 for use in its PCs. Although MS-DOS and PC DOS were initially developed in parallel by Microsoft and IBM, the two products diverged after twelve years, in 1993, with recognizable differences in compatibility, syntax, and capabilities.
During its lifetime, several competing products were released for the x86 platform and MS-DOS went through eight versions, until development ceased in 2000. Initially, MS-DOS was targeted at Intel 8086 processors running on computer hardware using floppy disks to store and access not only the operating system, but application software and user data as well. Progressive version releases delivered support for other mass storage media in ever greater sizes and formats, along with added feature support for newer processors and rapidly evolving computer architectures. Ultimately, it was the key product in Microsoft's development from a programming language 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
MS-DOS was a renamed form of 86-DOS – owned by Seattle Computer Products, written by Tim Paterson. Development of 86-DOS took only six weeks, as it was basically a clone of Digital Research's CP/M (for 8080/Z80 processors), ported to run on 8086 processors and with two notable differences compared to CP/M: an improved disk sector buffering logic, and the introduction of FAT12 instead of the CP/M filesystem. This first version was shipped in August 1980. Microsoft, which needed an operating system for the IBM Personal Computer hired Tim Paterson in May 1981 and bought 86-DOS 1.10 for US$75,000 in July of the same year. Microsoft kept the version number, but renamed it MS-DOS. They also licensed MS-DOS 1.10/1.14 to IBM, which, in August 1981, offered it as PC DOS 1.0 as one of three operating systems for the IBM 5150, or the IBM PC
Within a year, Microsoft licensed MS-DOS to over 70 other companies. It was designed to be an OS 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. To this end, MS-DOS was designed with a modular structure with internal device drivers (the DOS BIOS), minimally for primary disk drives and the console, integrated with the kernel and loaded by the boot loader, and installable device drivers for other devices loaded and integrated at boot time. The OEM would use a development kit provided by Microsoft to build a version of MS-DOS with their basic I/O drivers and a standard Microsoft kernel, which they would typically supply on disk to end users along with the hardware. Thus, there were many different versions of "MS-DOS" for different hardware, and there is a major distinction between an IBM-compatible (or ISA) machine and an MS-DOS [compatible] machine. Some machines, like the Tandy 2000, were MS-DOS compatible but not IBM-compatible, so they could run software written exclusively for MS-DOS without dependence on the peripheral hardware of the IBM PC architecture.
This design would have worked well for compatibility, if application programs had only used MS-DOS services to perform device I/O, and indeed the same design philosophy is embodied in Windows NT (see Hardware Abstraction Layer). However, in MS-DOS's early days, the greater speed attainable by programs through direct control of hardware was of particular importance, especially for games, which often pushed the limits of their contemporary hardware. Very soon an IBM-compatible architecture became the goal, and before long all 8086-family computers closely emulated IBM's hardware, and only a single version of MS-DOS for a fixed hardware platform was needed for the market. This version is the version of MS-DOS that is discussed here, as the dozens of other OEM versions of "MS-DOS" were only relevant to the systems they were designed for, and in any case were very similar in function and capability to some standard version for the IBM PC—often the same-numbered version, but not always, since some OEMs used their own proprietary version numbering schemes (e.g. labeling later releases of MS-DOS 1.x as 2.0 or vice versa)—with a few notable exceptions.
Microsoft omitted multi-user support from MS-DOS because Microsoft's Unix-based operating system, Xenix, was fully multi-user. The company planned, over time, to improve MS-DOS so it would be almost indistinguishable from single-user Xenix, or XEDOS, which would also run on the Motorola 68000, Zilog Z8000, and the LSI-11; they would be upwardly compatible with Xenix, which Byte in 1983 described as "the multi-user MS-DOS of the future". Microsoft advertised MS-DOS and Xenix together, listing the shared features of its "single-user OS" and "the multi-user, multi-tasking, UNIX-derived operating system", and promising easy porting between them. After the breakup of the Bell System, however, AT&T Computer Systems started selling UNIX System V. Believing that it could not compete with AT&T in the Unix market, Microsoft abandoned Xenix, and in 1987 transferred ownership of Xenix to the Santa Cruz Operation (SCO).
On March 25, 2014, Microsoft made the code to SCP MS-DOS 1.25 and a mixture of Altos MS-DOS 2.11 and TeleVideo PC DOS 2.11 available to the public under the Microsoft Research License Agreement, which makes the code source-available, but not open source as defined by Open Source Initiative or Free Software Foundation standards. Microsoft would later re-license the code under the MIT License on September 28, 2018, making these versions free software.
As an April Fool's Day joke in 2015, Microsoft Mobile launched a Windows Phone application called MS-DOS Mobile which was presented as a new mobile operating system and worked similar to MS-DOS.
Versions
Microsoft licensed or released versions of MS-DOS under different names like Lifeboat Associates "Software Bus 86" a.k.a. SB-DOS, COMPAQ-DOS, NCR-DOS or Z-DOS before it eventually enforced the MS-DOS name for all versions but the IBM one, which was originally called "IBM Personal Computer DOS", later shortened to IBM PC DOS. (Competitors released compatible DOS systems such as DR DOS and PTS-DOS that could also run DOS applications.)
In the former Eastern bloc, MS-DOS derivatives named DCP (Disk Control Program [de]) 3.20 and 3.30 existed in the late 1980s. They were produced by the East German electronics manufacturer VEB Robotron.
Only to mention some notable versions…
MS-DOS 1.x
DOS 1.x was very limited in what it could do. It could start applications (.COM and .EXE), and process batch files (.BAT). DOS 1.0 worked with 160KB floppies and did not support folders (all files had to be in the root). The command interpreter supported the following commands:
- DIR, TYPE, COPY, ERASE, RENAME
- PAUSE, REM
No pipes, redirection, or device drivers were supported. The DOS API in 1.0 was very limited.
MS-DOS 1.25, the equivalent of PC-DOS 1.10, was the first version licensed to OEMs beyond IBM or Seattle Computer Products.
Some vendors labeled their versions of MS-DOS with different names and version numbers. All of the versions here are believed to be based off of MS-DOS 1.25, even if the vendor called it something else.
- Version 1.10 (OEM) – possible basis for IBM's Personal Computer DOS 1
- Version 1.11 (OEM) – possible basis for IBM's Personal Computer DOS 1.0
- Compaq-DOS 1.12, a Compaq OEM version of MS-DOS (1.25 or higher)
- Version 1.14 (OEM) – possible basis for IBM's Personal Computer DOS 1.0
- Zenith Z-DOS 1.19, a Zenith OEM version of MS-DOS (1.25 or higher)
- Version 1.24 (OEM) – basis for IBM's Personal Computer DOS 1.1
- Version 1.25 (OEM) – basis for non-IBM OEM versions of MS-DOS, including SCP MS-DOS 1.25
MS-DOS 2.x
Adds support for 5.25 inch 260kb floppy drives, user installable device drivers and the first version to support folders and tree structurable file system.
MS-DOS 3.x
DOS 3.0 adds support for FAT16 partitions up to 32MB, 1.2MB floppy drives, and the IBM AT internal clock.
MS-DOS 3.0x is extremely rare. After the release of IBM PC-DOS 3.0, Microsoft dragged their feet providing MS-DOS 3.x to other OEMs, possibly to appease IBM. Most OEMs didn't get MS-DOS 3.x until 3.1.
Apricot and Compaq MS-DOS 3.0x versions are known to exist. Zenith and AT&T are suspected to exist.
MS-DOS 3.20 is the first release offered as a "vanilla" boxed set directly to consumers, instead of just OEMs.
MS-DOS 3.30 was a very popular version of MS-DOS. Due to the problems with 4.0, and 3.31 only being available via OEM, many users stuck with 3.30 unless they needed larger hard drive support.
MS-DOS 3.31 was only sold through a few OEMs, mainly Compaq.
This version adds support for hard drives up to 512MB.
It also does not use as much conventional memory as DOS 4.x or later, making it a good choice for 8088/8086 based computers.
- Version 3.0 (OEM) – First version to support 5.25-inch, 1.2 MB floppy drives and diskettes.
- Version 3.1 (OEM) – Support for Microsoft Networks
- Version 3.2 (OEM) – First version to support 3.5-inch, 720 kB floppy drives and diskettes.
- Version 3.22 (OEM) – (HP 95LX)
- Version 3.3 (OEM) – First version to support 3.5-inch, 1.44 MB floppy drives and diskettes (OEM)
- Version 3.31 (OEM) – supports FAT16B and larger drives
MS-DOS 4.0
MS-DOS 4 added support for hard drive partitions up to 2GB. It used much more of the base 640K, and was somewhat buggy.
Microsoft had long planned that MS-DOS "4" would be a multitasking-capable operating system, but IBM had insisted on creating a new version of regular DOS for use with their PS/2 computers. The below versions, as released to the consumer market, are based on DOS 3.3x and IBM's PC-DOS 4.0 enhancements. Although essentially scrapped, some narrow European markets did receive Microsoft's Multitasking MS-DOS 4.0
Microsoft's initial 4.00 release (File dates 10/6/1988) was quickly followed up by 4.01, making this an uncommon version. To add to the confusion, most OEMS badged their 4.01 disks as "4" or "4.0".
Includes a graphical/mouse interface. It had many bugs and compatibility issues.
- Version 4.00 (OEM) – First version to support a single hard disk partition that is greater than 32 MiB and up to a maximum size of 2 GB
- Version 4.01 (OEM) – Microsoft rewritten Version 4.00 released under MS-DOS label but not IBM PC DOS. First version to introduce volume serial number when formatting hard disks and floppy disks (Disk duplication also and when using SYS to make a floppy disk or a partition of a hard drive bootable).
- Version 4.01a (OEM)
MS-DOS 5.0
MS-DOS 5 introduced numerous new features and was a flagship release for Microsoft. A full screen text editor EDIThas replaced the former line editor EDLIN supplied since the early days of DOS. Microsoft QBasic also shipped in DOS 5 replacing GW-BASIC. MS-DOS 5 also supported 2.88MB 3.5" floppy disks as well as hard disks up to 2GB in size. The memory management was rewritten to allow DOS to utilize the High Memory Area and Upper Memory Area to reduce its usage of conventional memory. Numerous bugs were noticed shortly after launch which lead to the 5.0a update.
This release of DOS was the last of the collaboration between Microsoft and IBM and as a result will be the last result where PC-DOS and MS-DOS are near-identical. This was also the version of DOS used in the OS/2 and Windows NT virtual DOS machine.
When MS-DOS 5 was released the entire market had become dominated by IBM and compatible systems, so specific OEM versions of DOS for machines not using an IBM BIOS were not shipped as in prior releases.
- Version 5.0 (Retail) – includes a full-screen editor. A number of bugs required re issue. First version to support 3.5-inch, 2.88 MB floppy drives and diskettes. Hard disk partitions greater than 32 MiB and up to a maximum size of 2 GB was now provided by the MS-DOS kernel.First version to load portions of the operating system into the high memory area.
- AST Premium Exec DOS 5.0 (OEM) – a version for the AST Premium Exec series of notebooks with various extensions, including improved load-high and extended codepage support
- Version 5.0a (Retail) – With this release, IBM and Microsoft versions diverge
- Version 5.50 (Windows NTVDM) – All Windows NT 32-bit versions ship with files from DOS 5.0
MS-DOS 6.x
MS-DOS 6.0 includes many new utilities and features, including a disk defragmenter, disk compression, anti-virus, a new backup system, and pc-pc file transfer tools. It was heavily criticized as buggy by the media, primarily due to file corruption issues with DoubleSpace and the lack of tools to repair such issues.
Note that the boot sector OEM ID of "MSDOS6.0" is correct and genuine. Microsoft reverted to using "MSDOS5.0" on later disks.
Microsoft intentionally skipped "6.1" to prevent confusion with IBM's independently produced PC-DOS 6.1. Microsoft also made a free/inexpensive 6.0 -> 6.2 step up kit available.
This update corrects some major bugs in DoubleSpace, introduces ScanDisk, adds automounting of compressed floppies, and a tool to uncompress DoubleSpace compressed drives.
MS-DOS 6.21
This version was specifically released to remove DoubleSpace due to legal injunction. Their replacement "DriveSpace" was not yet ready.
MS-DOS 6.22
Microsoft DOS 6.22 was the last standalone version from Microsoft. It was also the last from Microsoft to run on an 8088, 8086, or 286.
6.22 adds DriveSpace, a replacement for DOS 6.20's DoubleSpace drive compression that was removed in 6.21.
There's a really detailed tutorial located at http://legroom.net/howto/msdos that gives tips on how to customize DOS. We suggest you follow this tutorials suggestions for setting up and customizing DOS. However, if you're installing to a virtual machine, writing the disk images to actual floppies isn't really necessary.
Version 6.0 (Retail) – Online help through QBASIC. Disk compression, upper memory optimization and antivirus included.
Version 6.2 – Scandisk as replacement for CHKDSK. Fix serious bugs in DBLSPACE.
Version 6.21 (Retail) – Stacker-infringing DBLSPACE removed.
Version 6.22 (Retail) – New DRVSPACE compression.
Under the Microsoft Windows era
MS-DOS 7.x
Version 7.0 (Windows 95, Windows 95A) – Support for VFAT long file names and 32-bits signed integer errorlevel. New editor. JO.SYS is an alternative filename of the IO.SYS kernel file and used as such for "special purposes". JO.SYS allows booting from either CD-ROM drive or hard disk. Last version to recognize only the first 8.4 GB of a hard disk. The "VER" internal command prompt reports the Windows version 4.00.950.
Version 7.1 (Windows 95B – Windows 98 – Windows 98SE) – Support for FAT32 file system. Last general purpose DOS to load Windows. The "VER" internal command prompt reports the Windows version 4.00.1111, 4.10.1998 or 4.10.2222
MS-DOS 8.x
Version 8.0 (Windows ME) – Integrated drivers for faster Windows loading. Four different kernels (IO.SYS) observed.[nb 4] The "VER" internal command prompt reports the Windows version 4.90.3000.
Version 8.0 (Windows XP) – DOS boot disks created by XP and later contain files from Windows ME. The "VER" internal command prompt reports the Windows version 5.1.
Localized Versions
Localized versions of MS-DOS existed for different markets.[69] While Western issues of MS-DOS evolved around the same set of tools and drivers just with localized message languages and differing sets of supported codepages and keyboard layouts, some language versions were considerably different from Western issues and were adapted to run on localized PC hardware with additional BIOS services not available in Western PCs, support multiple hardware codepages for displays and printers, support DBCS, alternative input methods and graphics output. Affected issues include Japanese (DOS/V), Korean, Arabic (ADOS 3.3/5.0), Hebrew (HDOS 3.3/5.0), Russian (RDOS 4.01/5.0) as well as some other Eastern European versions of DOS.
Notable MS DOS Applications
( there were so many ... )
A System or Operating System / Platform / Architecture is only as good as the Applications available for it.
Text Editors and Office Suites
Spreadsheets and Databases
Development Tools
File Management
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. In fact, there remains controversy as to whether QDOS was more or less plagiarized from early versions of CP/M code. 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; many applications were 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 originally supported the simple .COM, which was modeled after a similar but binary-incompatible format known from CP/M-80. CP/M-86 instead supported a relocatable format using the file extension .CMD to avoid name conflicts with CP/M-80 and MS-DOS .COM files. MS-DOS version 1.0 added a more advanced relocatable .EXE executable file format.
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-DOS/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 multi-tasking (as was available in operating systems since 1963) 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 PC1512, were sold with floppy disks for two operating systems (only one of which could be used at a time), MS-DOS and CP/M-86 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 5.0, which included features only available as third-party add-ons for MS-DOS. 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 6.0, 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, then 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).
The pact between Microsoft and IBM to promote OS/2 began to fall apart in 1990 when Windows 3.0 became a marketplace success. Much of Microsoft's further contributions to OS/2 also went into creating a third GUI replacement for DOS, Windows NT.
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.
Legal Issue
As a response to Digital Research's DR DOS 6.0, which bundled SuperStor disk compression, Microsoft opened negotiations with Stac Electronics, vendor of the most popular DOS disk compression tool, Stacker. In the due diligence process, Stac engineers had shown Microsoft part of the Stacker source code. 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.[71]
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. 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 U.S. government Federal Trade Commission began investigating Microsoft's licensing procedures, resulting in a 1994 settlement agreement limiting Microsoft to per-copy licensing. Digital Research did not gain by this settlement, and years later its successor in interest, Caldera, sued Microsoft for damages in the Caldera v. Microsoft lawsuit. It was believed that the settlement ran in the order of $150 million, but was revealed in November 2009 with the release of the Settlement Agreement to be $280 million.
MS DOS modern alternatives
Freedos
Freedos is still available today and actively developed. Can install it on Virtuablox or on bare metal.
4DOS (4OS2 - OS/2 Version as well and 4NT - 4DOS for WindowsNT)
4DOS
Interesting Fact / Add-on:
4NT's TCI - Take Command Interface still exists today as JP Software's TC (TCI + TCC)
This program allowed one to attach (thereby reducing screen clutter) and detach tabbed consoles to a single window. This program requires Windows XP or later.
A new version of Take Command extends the original Tabbed Command Interface, expanded with extra windows to allow input to be composed, to graphically navigate directories and files, and extra features. 4NT is bundled as Take Command Console. A light feature-reduced version of TCC is released as a free download.
JP Software then released:
- TC (full pack of TCI + TCC)
- TCLE (TCI + TCC/LE) - Full Pak with TCC/LE formerly known as 4NT ( free unsupported version)
- TCC (just the command utility)
- TCC/LE - TCC/LE formerly known as 4NT ( free unsupported version)
Dosbox / DOSEMU
Using MS DOS ( or its alternatives) Today
You can install FreeDOS on bare metal or in Virtualbox/Vmware as a VM or 4DOS or other DOS Emulators like Dosbox / DOSEMU or alternatives under most other operating systems: Windows, Linux, Mac. Solaris 10 SPARC even has a working DOSBOX binary ( does not play nice with the Sun keyboard and it should be built with some extra config flags so it is solved but works fine via ssh -X with X11Forward and as long as its not very graphics intensive application ( like a game sensitive to FPS) I can run it just fine.)
Dosbox , vDOS , DOSEMU or alternatives can be a quick and dirty/easy way to get up and running quick to run your favourite DOS programs from the era.
True Die Hard Fans are building retro computers or purchasing retro battlestations which are era-appropriate and as a result can find a 486 desktop computer for a price of a new laptop sometimes on sites like ebay. -- Remember Old Hardware many times can come with failed or failing parts which might not be easy to source and sometimes even replace them can be a challange ( if you have the skills and you are up to it)
I agree some of them look so good you want to have them. 🙂
Use of Undocumented APIs
As a response to Digital Research's DR DOS 6.0, which bundled SuperStor disk compression, Microsoft opened negotiations with Stac Electronics, vendor of the most popular DOS disk compression tool, Stacker. In the due diligence process, Stac engineers had shown Microsoft part of the Stacker source code. 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.[71]
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. 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 U.S. government Federal Trade Commission began investigating Microsoft's licensing procedures, resulting in a 1994 settlement agreement limiting Microsoft to per-copy licensing. Digital Research did not gain by this settlement, and years later its successor in interest, Caldera, sued Microsoft for damages in the Caldera v. Microsoft lawsuit. It was believed that the settlement ran in the order of $150 million, but was revealed in November 2009 with the release of the Settlement Agreement to be $280 million.
Windows Command Line Interface
All versions of Microsoft Windows have had an MS-DOS or MS-DOS-like command-line interface (CLI) called MS-DOS Prompt which redirected input to MS-DOS and output from MS-DOS to the MS-DOS Prompt, or, in later versions, Command Prompt. This could run many DOS and variously Win32, OS/2 1.x and POSIX command-line utilities in the same command-line session, allowing piping between commands. The user interface, and the icon up to Windows 2000, followed the native MS-DOS interface. It is to be noted that the Command Prompt introduced with Windows NT is not actually MS-DOS, rather a CLI which shares some commands with MS-DOS.
Earlier Versions of Windows
The 16-bit versions of Windows (up to 3.11) ran as a Graphical User Interface (GUI) on top of MS-DOS. With Windows 95, 98, 98 SE and Me, the role of MS-DOS was reduced to a boot loader, with MS-DOS programs running in a virtual DOS machine within 32-bit Windows, with ability to boot directly into MS-DOS retained as a backward compatibility option for applications that required real mode access to the hardware, which was generally not possible within Windows.[73] The command line accessed the DOS command line (usually COMMAND.COM) through a Windows module (WINOLDAP.MOD).
Windows NT
Windows NT based operating systems boot through a kernel whose sole purpose is to load Windows. One cannot run Win32 applications in the loader system in the manner that OS/2, UNIX or Consumer Windows can launch character-mode sessions.
The command session permits running of various supported command-line utilities from Win32, MS-DOS, OS/2 1.x and POSIX. The emulators for MS-DOS, OS/2 and POSIX use the host's window in the same way that Win16 applications use the Win32 explorer. Using the host's window allows one to pipe output between emulations.
The MS-DOS emulation takes place through the NTVDM (NT Virtual DOS Machine). This is a modified SoftPC (a former product similar to VirtualPC), running a modified MS-DOS 5 (NTIO.SYS and NTDOS.SYS). The output is handled by the console DLLs, so that the program at the prompt (CMD.EXE, 4NT.EXE, TCC.EXE), can see the output. 64-bit Windows does not have either the DOS emulation, or the DOS commands EDIT, DEBUG, EDLIN), that come with 32-bit Windows.
The DOS version returns 5.00 or 5.50, depending on which API function is used to determine it. Utilities from MS-DOS 5.00 run in this emulation without modification. The very early beta programs of NT show MS-DOS 30.00, but programs running in MS-DOS 30.00 would assume that OS/2 was in control.
The OS/2 emulation is handled through OS2SS.EXE and OS2.EXE, and DOSCALLS.DLL. OS2.EXE is a version of the OS/2 shell (CMD.EXE), which passes commands down to the OS2SS.EXE, and input-output to the Windows NT shell. Windows 2000 was the last version of NT to support OS/2. The emulation is OS/2 1.30.
POSIX is emulated through the POSIX shell, but no emulated shell; the commands are handled directly in CMD.EXE.
The Command Prompt is often called the MS-DOS prompt. In part, this was the official name for it in Windows 9x and early versions of Windows NT (NT 3.5 and earlier), and in part because the SoftPC emulation of DOS redirects output into it. Actually only COMMAND.COM and other 16-bit commands run in an NTVDM with AUTOEXEC.NT and CONFIG.NT initialisation determined by _DEFAULT.PIF, optionally permitting the use of Win32 console applications and internal commands with an NTCMDPROMPT directive.
Win32 console applications use CMD.EXE as their command prompt shell. This confusion does not exist under OS/2 because there are separate DOS and OS/2 prompts, and running a DOS program under OS/2 will launch a separate DOS window to run the application.
All versions of Windows for Itanium (no longer sold by Microsoft) and x86-64 architectures no longer include the NTVDM and can therefore no longer natively run DOS or 16-bit Windows applications. There are alternatives in the form of virtual machine emulators such as Microsoft's own Virtual PC, as well as VMware, DOSBox, and others.
End of Life
The introduction of Windows 3.0 in 1990, with an easy-to-use graphical user interface, marked the beginning of the end for the command-line driven MS-DOS. With the release of Windows 95 (and continuing in the Windows 9x product line through to Windows Me), an integrated version of MS-DOS was used for bootstrapping, troubleshooting, and backwards-compatibility with old DOS software, particularly games, and no longer released as a standalone product.[74] In Windows 95, the DOS, called MS-DOS 7, can be booted separately, without the Windows GUI; this capability was retained through Windows 98 Second Edition. Windows Me removed the capability to boot its underlying MS-DOS 8.0 alone from a hard disk, but retained the ability to make a DOS boot floppy disk (called an "Emergency Boot Disk") and can be hacked to restore full access to the underlying DOS. On December 31, 2001, Microsoft declared all versions of MS-DOS 6.22 and older obsolete and stopped providing support and updates for the system.[75] As MS-DOS 7.0 was a part of Windows 95, support for it also ended when Windows 95 extended support ended on December 31, 2001.[76] As MS-DOS 7.10 and MS-DOS 8.0 were part of Windows 98 and Windows ME respectively, support also ended when Windows 98 and ME extended support ended on on July 11, 2006, thus ending support and updates of MS-DOS from Microsoft.
In contrast to the Windows 9x series, the Windows NT-derived 32-bit operating systems (Windows NT, 2000, XP and newer), developed alongside the 9x series, do not contain MS-DOS compatibility as a core component of the operating system nor do they rely on it for bootstrapping, as NT was not with the level of support for legacy MS-DOS and Win16 apps that Windows 9x was,[74] but does provide limited DOS emulation called NTVDM (NT Virtual DOS Machine) to run DOS applications and provide DOS-like command prompt windows. 64-bit versions of Windows NT do not provide DOS emulation and cannot run DOS applications natively.[78] Windows XP contains a copy of the Windows Me boot disk, stripped down to bootstrap only. This is accessible only by formatting a floppy as an "MS-DOS startup disk". Files like the driver for the CD-ROM support were deleted from the Windows Me bootdisk and the startup files (AUTOEXEC.BAT and CONFIG.SYS) no longer had content. This modified disk was the base for creating the MS-DOS image for Windows XP. Some of the deleted files can be recovered with an undelete tool.[79] When booting up an MS-DOS startup disk made with Windows XP's format tool, the version number and the VER internal command reports as "Windows Millennium" and "5.1" respectively and not "MS-DOS 8.0" (which was used as the base for Windows Me but never released as a stand-alone product), though the API still says Version 8.0.
When creating a DOS startup disk on Windows Vista, the files on the startup disk are dated April 18, 2005 but are otherwise unchanged, including the string "MS-DOS Version 8 Copyright 1981–1999 Microsoft Corp" inside COMMAND.COM. Windows 7, 8, and 8.1 can also create a MS-DOS startup disk. Starting with Windows 10, the ability to create a DOS startup disk has been removed and so either a virtual machine running MS-DOS or an older version (in a virtual machine or dual boot) must be used to format a floppy disk, or an image must be obtained from an external source. Other solutions include using DOS compatible alternatives, such as FreeDOS or even copying the required files and boot sector themselves. With Windows 11, the operating system does not support NTVDM as it's only 64-bit, thus removing any remaining support for MS-DOS or it's applications from Microsoft.
MS-DOS 6.22 was the last standalone version produced by Microsoft for Intel 8088, Intel 8086, and Intel 80286 processors, which remain available for download via their MSDN,[80] volume license, and OEM license partner websites, for customers with valid login credentials. MS-DOS is still used in embedded x86 systems due to its simple architecture and minimal memory and processor requirements, though some current products have switched to the still-maintained open-source alternative FreeDOS.
In 2018, Microsoft released the source code for MS-DOS 1.25 and 2.0 on GitHub. The purpose of this, according to Microsoft, is mainly for education and experimentation with historic operating systems and for new programmers to gain an understanding of how low-level software works, both historic and current. According to program manager Rich Turner, the other versions could not be open-sourced due to third-party licensing restrictions.[81]
Due to the historical nature of the software, Microsoft will not accept any pull requests to the code; only pull requests for modified and translated documentation will be accepted. Users, however, are allowed and fully encouraged to fork the repository containing the MS-DOS source code and make their own modifications, and do whatever they like with it.
Legacy Compatibility
From 1983 onwards, various companies worked on graphical user interfaces (GUIs) capable of running on PC hardware. However, this required duplicated effort and did not provide much consistency in interface design (even between products from the same company).
Later, in 1985, Microsoft Windows 1.0 was released as Microsoft's first attempt at providing a consistent user interface (for applications). The early versions of Windows ran on top of MS-DOS. At first Windows met with little success, but this was also true for most other companies' efforts as well, for example GEM. After version 3.0, Windows gained market acceptance.
Windows 9x used MS-DOS to boot the Windows kernel in protected mode. Basic features related to the file system, such as long file names, were only available to DOS applications when running through Windows. Windows NT runs independently of DOS but includes NTVDM, a component for simulating a DOS environment for legacy applications.
Closing Thoughts
I like especially the era of the 80s and 90s of computing and the home computer boom which occurred throughout the world. OK , fair enough I was born in '82 and it left me with no choice in the matter. But I have always thought it was a conscious decision form my part.
The speed and leaps computing evolved at those times when it came to hardware or software was something magical.Each month and year brought something significant , something new , something we thought just some time ago that it can not be done or seemed impossible to achieve.
Performance , disk space , new peripherals
usenet, bbs then the internet and email and the rest became history
One particular part I really miss and love about this era that computers could and were important tools which let you focus on the task at hand you had to handle without distractions. Think of word processors or office suites applications for handling spreadsheets or making a presentation or write a program.
No ads, nagging updates and not another 300x popups and messages from various parts of the system and from other applications ( you did not even realized before those things were your computer ) or system updates trying to take your attention away from what You were actually doing just a minute ago.
In this sense the 80s always reminds me this era of simplicity like a typewriter. The beauty in doing less or sometimes only a single function ( perhaps at a time...) but letting you immerse in that experience and focus and concentrate.
Today the user interfaces are so colorful it sometimes becomes a distraction so many things trying to grab my attention like I mentioned. It can be very overwhelming very quickly. Messages, popups, notifications, ads, more ads.... ah.
When All I want sometimes is to achieve one single thing:
being it writing my thoughts down or to do a presentation , perhaps make some simple calculations or just one and only one task at a time but to do it well.
There is beauty in simplicity and being distraction free.
This is the reason I like to just go back sometimes into MS-DOS and bring up one single application at a time and just use it to do one single thing and not let anything else taking me away from that....
It also reminds me of Modern Cars Vs Classic Cars 🙂
Links
https://dos.fandom.com/wiki/MS-DOS_Version_History
https://www.computerhope.com/history/dos.htm
https://freesoft.dev/program/148467749
http://www.columbia.edu/~em36/wpdos/
https://vetusware.com/download/WordPerfect%20Suite%206.2/?id=3797
https://jpsoft.com/products/tcc-cmd-prompt.html