o this day are PC / GEOS , OpenGEM (a free further development of the original GEM by Digital Research ) and the developments around MatrixOS , Qube3P and SEAL .
Very old versions of Microsoft Windows up to and including Windows 2.x were just graphical extensions for MS-DOS. They were developed as an optional extension of MS-DOS and are also sold separately. Windows 3.x uses DOS routines in many areas, but already has essential components of an independent operating system with its own scheduler and memory management. Windows 95 and all successors based on it use DOS to start and run DOS-based programs; 32-bit programs rarely use DOS operating system routines, as the Win32 API replaces them in principle. The versions of MS-DOS (MS-DOS 7, 8) specially adapted for Windows are mandatory for starting the respective Windows 9x version. These further developed MS-DOS versions were no longer available individually, but only an integral part of all versions of Windows 95, Windows 98 and, most recently, Windows Me , which appeared in 2000. After that the further development was stopped.
DOS systems are considered obsolete and today, unless they are an operating system component, are practically only used on legacy systems, for operating old DOS software in emulators or in niche markets.
As an operating system
DOS operating systems are used for embedded systems .
From OEMs are DOS systems, in particular the freely available and thus license-free FreeDOS, often used to have to sell PCs not entirely without an operating system, not incorporating Windows still want to install Linux.
In order to be able to continue using software that is not compatible with newer operating systems, it is found as a fully installed system on a PC with several operating systems ( multi-boot systems ), from which one can then select a system when booting. This way has now largely been replaced by DOS emulators.
These operating systems are also used for a BIOS or firmware update. They are also used for bootable emergency and repair media, especially for combating malware , because the usual malware cannot run on DOS systems. The DOS enables virus scanners to be started and simple file processing. The same applies to recovery CDs from image programs.
OS / 2 , the operating system developed by IBM and Microsoft from 1987 onwards, was no longer based on DOS, although there are certain peculiarities of the DOS system. The downward compatibility required at that time was ensured via the DOS emulation kernel , also known as multithreading (Multiple Virtual DOS Machine , MVDM) . This technology, which was revolutionary at the time, has also turned out to be a major weak point, because the DOS mode only ran exclusively on the screen and all drivers had to take part in the switchover to DOS mode. Later 32-bit versions from 1991 onwards allowed DOS multitasking sessions with their own window manager ( Workplace Shell , Presentation Manager ). Even more modern Windows such as Windows NT , Windows 2000 , Windows XP , Windows Vista and all newer versions are based on the kernel of the 32.bit operating system Windows NT 3.1, introduced in 1991, which was completely redeveloped at the time and has no "DOS roots": MS-DOS / PC DOS is neither a component nor the technical basis of these operating systems, although the Win32 subsystem of modern 32-bit Windows versions still simulates the functionality of MS-DOS. More modern OS / 2 versions followed the same path: The DOS box ( command line ) runs in these systems as an interpreter ( cmd.exe , COMMAND.COM), which emulates DOS in order to execute programs written in DOS. The function is that of a scripting language . The 64-bit versions of Windows XP and later no longer have the ability to run MS-DOS programs.
Today there are DOS emulators such as DOSBox , which runs on different operating systems, and the Linux program DOSEMU . Instead, however, entire PC emulators (see also virtualization ) can be used that attempt to reproduce the hardware of a computer true to the original. An original DOS can be installed and used on suc