DOS is an acronym for Disk Operating System but, in common usage, it has come to refer to the disk-based operating systems on personal computers compatible with the IBM PC.
A disk operating system is one that can use a disk storage device, such as a floppy disk, a hard drive, or an optical disk, providing a file system that can organize, read, and write files to the disk. This definition doesn't apply to most modern operating systems, like Apple Macintosh or Microsoft Windows, and is largely applied to older generations of operating systems.
Given that large numbers of older computers are still in use, DOS-type operating systems may still be relevant, however.
Most of the DOS resources referenced in this guide will be historic in nature, and most are no longer supported by their developers, although some are in the public domain or otherwise available.
Although there may be others, one notable exception is FreeDOS, previously known a Free-DOS and PD-DOS. FreeDOS began when Microsoft announced its discontinuance of MS-DOS in 1994, releasing its first version in 1998. Available under the terms of the GNU General Public License, FreeDOS continues to be actively developed.
Another is ROM-DOS, which was introduced in 1989 as an MS-DOS compatible operating system for embedded systems. Additional enhancements have been made to the operating system over the years, and it is still available from its developer, Datalight Tuxera Company, as closed-source software. A single-user version of ROM-DOS is also available for desktop users looking for a replacement DOS.
Other recently active versions of DOS include DR-DOS, RxDOS, REAL/32, and SpartaDOS. Developed in Russia by PhysTechSoft and Paragon Technology Systems, PTS-DOS (PTS/DOS) is a DOS clone still in development for the Russian Ministry of Defense.
Reportedly, on request, some computer manufacturers, including Dell and HP, will sell computers with FreeDOS or DR-DOS installed as original equipment manufacturer (OEM) operating systems.
On most Linux systems, it is possible to run copies of DOS on a Linux-native virtual machine, and there are various emulators available for running DOS on Unix-type systems and Microsoft Windows. DOSBox, for example, is used for legacy gaming on modern operating systems.
Early versions of Microsoft Windows were, in effect, a graphical shell over a DOS system, and users could drop to a DOS command line to run non-graphical DOS programs. Windows 95 was bundled as a standalone operating system that was not dependent on DOS, although the MS-DOS component remained for the sake of compatibility.
However, most computer users today have never used a computer from the DOS command line.
Developed for IBM by Microsoft, PC-DOS was the first widely-installed operating system used in personal computers on Intel 8086 16-bit processors. Microsoft subsequently produced its own nearly identical version called MS-DOS.
Other early computers, the Commodore 64, Atari 800, and Apple II, featured DOS systems, known as CBCM DOS, Atari DOS, and Apple DOS, respectively.
These early operating systems did not multitask; they were able to run only one program at a time. Using a command-line interface, users had to remember the commands that were needed to accomplish computing tasks. The command line was also known as the C-prompt (C:\) or the DOS prompt.
The last retail version of MS-DOS was MS-DOS 6.22. Although MS-DOS was bundled with Windows after that, it no longer required a separate license and was not distributed as a standalone operating system.
The last retail version of PC-DOS was PC-DOS 2000, although IBM later created PC DOS 7.10 for OEM use.
Besides the few versions of DOS that continue to be actively supported, legacy copies of past versions are available from various sources. Some of these may be in the public domain, but the legality of others might be in question.
Whatever the version, topics related to DOS operating systems are appropriate topics for this category.
Recommended Resources
The site offers information about 4DOS, a command-line interpreter by JP Software, designed to replace the default interpreter in DOS, Windows, and OS/2, although it is most often used with the MS-DOS/Windows 95 stream of operating systems, IBM PC DOS, and DR-DOS versions. The site includes a collection of 4DOS versions that may be downloaded without charge, various tips and tricks, 4DOS-aware programs, and links to other related sites.
https://www.4dos.info/
Apponic is a comprehensive download site that offers free downloads of thousands of software applications. Here, it offers a free download of MS-DOS, Microsoft’s last distributed version of MS-DOS, including English, French, German, Portuguese, and Spanish versions. A brief overview of MS-DOS is given, including some of its current uses, along with technical specifications, such as the date of distribution, licensure data, file size, and developer.
https://ms-dos.apponic.com/
The goal of ArchiveOS is to save the operating systems of the past for future generations to find, try, and learn about them, largely for educational purposes. Included are a variety of DOS systems, such as CarbonOS, CraftyOS, DOS-C, DR-DOS/OpenDOS, GLaDOS, LightDOS, LightOS, NX-DOS, and uDOS. For each, a profile of the OS is presented, including release dates, version numbers, the architecture the OS was produced for, and a download link.
https://archiveos.org/dos/
Datalight is a US-based software company that specializes in failsafe and high-performance software for embedded systems. One of its products, ROM-DOS (Datalight DOS) is an MS-DOS compatible OS designed for embedded systems, although the company also offers a single-user version for desktop users who need a replacement DOS. The features and benefits of both versions are highlighted, including comparisons between ROM-DOS SDK and ROM-DOS SUV and MS-DOS 6.22.
https://www.datalight.com/products/rom-dos/
Digital Research is a software company created to develop the CP/M operating system and related systems, such as MP/M, Concurrent DOS, FlexOS, Multiuser DOS, DOS Plus, DR DOS, and GEM. Its sub-site is focused on OpenDOS, released by Caldera in 1997. Featured is a history of the OS, user and programmer documentation, OpenDOS mailing lists, and unofficial FAQ, and a download link, through which the program files and OpenDOS password can be obtained.
http://www.deltasoft.com/opendos.htm
DOS the Easy Way Guide to MS-DOS
Written by Everett Murdock, Ph.D., DOS the Easy Way taught several people how to use the DOS operating system, and it is available here in downloadable form, including all of the original text and appendixes, including a large chapter on batch files, with coverage of all versions of DOS, including those provided with Windows XP, Vista, and Win 7 and 8. Also featured are a DOS command index and information on other books available in electronic form.
http://www.easydos.com/
Available for most common operating systems, DOSBox is an emulator program that emulates an IBM PC-compatible computer running a DOS operating system, including several compatible graphics and sound cards, offered primarily to allow original DOS programs, such as vintage DOS PC games, to be played on modern computers and computer operating systems. Distributed under the terms of the GNU General Public License, it is hosted on SourceForge.
https://www.dosbox.com/
A fork of DOSBox, DOSBox-X retains compatibility with the majority of DOS games that DOSBox was created for, while focusing on accurately emulating the vintage hardware that these games were run on, from IBM PC hardware with 64 K RAM up to the late 1990s hardware, depending on the software to be run, and includes emulation for Windows 95, 98, and ME. Available is a support wiki, an issues tracker, development and testing blog, and the source code.
http://dosbox-x.com/
Originally intended for DR-DOS only, the site now addresses current open-source DOS kernels, such as DR-DOS, FreeDOS, and programs, although it also provides information about legacy DOS kernels, like Novell DOS, OpenDOS, and related resources. Links to news relating to DOS systems are posted, and informational pages on several DOS topics are included, categorized alphabetically and findable through a keyword search. Links to other DOS resources are included.
http://www.drdos.org/
Previously known as Free-DOS and PD-DOS, FreeDOS is a free and open-source (GNU General Public License) operating system for IBM PC compatible computers, designed to form a complete DOS-compatible environment for running legacy software and supporting embedded systems. It can be booted from a floppy disk or USB flash drive and is intended to run well under virtualization or x86 emulation. The OS files may be freely downloaded from the site, which includes a support wiki.
http://www.freedos.org/
For reference purposes, the original source code and compiled binaries of the MS-DOS 1.25 and 2.0 versions of the operating system are provided and made available for cloning or downloading. These are the same files originally shared at the Computer History Museum on March 25, 2014, and are republished here under the MIT (OSI) License and the Microsoft Open Source Code of Conduct. The full text of the license is available here, along with contributors.
https://github.com/microsoft/ms-dos
Hosted on GitHub, PC-BASIC is a free, cross-platform emulator for the GW-BASIC family of interpreters, allowing users to run classic games and legacy BASIC applications designed for MS-DOS systems, IBM PC, PC Jr., or Tandy 1000, designed to be compatible with Microsoft’s GW-BASIC. It runs ASCII, tokenized and protected BASIC programs, and supports the Microsoft binary format for full interchangeability of data files. It is available as free and open-source software.
http://robhagemans.github.io/pcbasic/
Hosted on SourceForge, the PDOS Project includes the Public Domain Operating System (PDOS) and the Public Domain Project C Library (PDPCLIB), the former being an operating system with a user interface as simple as MS-DOS, the latter a public domain C runtime library through which the user can link C programs against to produce executables without licensing restrictions. Links to a download site and the documentation for both components are provided.
http://pdos.sourceforge.net/
PocketDOS is a virtual PC software environment for pocket computers that allows the user to run a DOS operating system, having access to several DOS applications on a pocket computer, while permitting the simultaneous use of the pocket computer’s native applications. Registration may be accomplished online, the requirements for use are stated, along with specifications, tutorials, a FAQ, and access to an online support forum. Other resources include screenshots and reviews.
http://www.pocketdos.com/
Based on Digital Research’s Multiuser DOS, Real/32 (Real/NG, IMS Multiuser DOS), from Intelligent Micro Software, is a real-time, multi-tasking, multiuser, DOS-compatible operating system. Real/32 includes preemptive multitasking that makes use of Intel 386, 486, and Pentium processors, as well as API features that allow custom-developed applications to communicate with one another. Created primarily for embedded POS systems and control systems it may be downloaded for free.
https://winworldpc.com/product/real-32/7x
Created for the Atari, SpartaDOS was not without its bugs and limitations, but new hardware and software developments encouraged a group of developers to organize as the SpartaDOS X Upgrade Project in a cooperative effort to come up with a cleaner, more modern version of SpartaDOS, abandoned by its developer. Designed to be compatible with MS-DOS 4.22, the OS requires an Atari 8-bit computer. Although proprietary, it may be downloaded from the site for free. A user guide is available.
http://sdx.atari8.info/
Designed to allow DOS applications to be run on recent versions of Windows, TameDOS supports single-user and multi-user environments, providing solutions to common DOS problems, and enhancing the application with simultaneous access to Windows features through an alternate GUI console with a customizable user interface. Pricing is based on the number of users. Its features, console usage, administrative guide, and technical references are available.
http://www.tamedos.com/
Offered as a commercial application, ExDOS is an MS-DOS emulator developed by Tao Software Development, designed to run DOS applications on newer operating systems like Windows 10, 7 and 8, Vista, XP, 2000, and Terminal Server. Available in three editions, Ultimate, Standard, and Print, the software is available as a free, fully-functional, 14-day trial, after which it would need to be purchased. Its support services and options are discussed.
http://www.taosdc.com/
Available as freeware, vDos may be registered in order to avoid an About popup that is displayed every three hours of continuous use on the freeware version. The software is designed to allow the user to run serious DOS applications in Windows 7 or later, 32 and 64-bit, but not for those who simply want to experiment with DOS. The application focuses exclusively on serious end-user programs and allows the running of multiple DOS applications simultaneously.
https://www.vdos.info/
WinWorld was created in 2003 to preserve and share old software, and the information necessary to use that software. The site offers downloads of most versions of MS-DOS, including 1.x, 2.x, 3.00, 3.10, 3.20, 3.21, 3.30, 3.31, 4.ox, 5.0, 6.0, 6.20, 6.21, 6.22, and 7.1 (CDU), along with a brief history of each, installation instructions, and other data, such as the product type, release date, minimum CPU, RAM, and free disk space required, user interface, and platform.
https://winworldpc.com/product/ms-dos/
