anager) are written completely in assembler, only parts of the shell COMMAND.COM and auxiliary programs were written in C.
PTS-DOS is an MS-DOS clone from Russia, which is written almost entirely in assembly language. It differs even more from MS-DOS in the handling and naming of system files than is the case with DR-DOS.
PTS-DOS was developed for the Russian military by the newly founded company PhysTechSoft in 1991 and was approved for commercial marketing by the Ministry of Defense. The first version was published in 1993 as PTS-DOS 6.4. After version 6.5, some of the manufacturer's programmers founded Paragon and developed their own versions of PTS-DOS using the source code. In the meantime, both lines are no longer being developed.
Other MS-DOS / PC-DOS compatible variants
There are many DOS that are at least partially compatible with MS-DOS, some common ones are:
- DCP : MS-DOS plagiarism from Robotron used in the GDR .
- Embedded DOS : DOS clone from General Software for Embedded Systems
- FreeDOS : Created to ensure the continued existence and further development of the DOS operating system
- PC-MOS / 386 : A multitasking, multi-user operating system that makes DOS applications available to multiple users.
- RxDOS : A completely invariant programmed DOS clone by Mike Podanoffsky
- ROM DOS : A DOS clone from Datalight for Embedded Systems
Initialization via batch commands
Under DOS, batch files (also known as "batch processing files " ) are often used in order to automatically execute sequences of commands. Since some DOS systems cannot save settings and they therefore expire after a restart, batch files are used to set them again each time the system is started (for example by means of
AUTOEXEC.BATa batch file that various DOS systems run automatically when they start up).
Graphical user interfaces for DOS
Many graphical user interfaces (also GUI , Graphical User Interface ) have been developed for MS-DOS and compatible DOS versions. Graphic user interfaces that have been further developed and available to 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, especial