 with LONGNAME, dynamically loadable support for LBA access and FAT32 drives with DRFAT32 as well as a POSIX -pthreads API extension) primarily attracted attention through several hundred optimizations and improvements in detail. In addition, special DR-DOS versions called "Winglue" or "Winbolt" were developed, which were compatible with Windows 95 (MS-DOS 7.0 + Windows 4.0) and Windows 98 (7.1 + Windows 4.1) and played an important role in the Caldera process vs. Microsoft played, but so far remained unpublished.
With the closure of the English development center in Andover at the beginning of 1999 and the outsourcing to Caldera Thin Clients, USA, a subsidiary of the Caldera mother, the further development of DR-DOS was abruptly stopped. DR-DOS 7.03 was initially distributed by Lineo or Embedix, which emerged from Caldera Thin Clients, and is still offered today by DRDOS, Inc. alias DeviceLogics for use in embedded systems.
Special OEM versions DR-DOS 7.04, 7.05, 7.06 and later also 7.07 (BDOS 7.3 / 7.4 / 7.7) and 7.08 (BDOS 7.8) with LBA and FAT32 support have been produced by the former developers of the system over the years developed.
Two versions have been released by DRDOS, Inc. DR-DOS 8.0 (2004) is an OEM version that goes back to DR-DOS 7.0x with LBA and FAT32 support with various extensions to the disk tools. DR-DOS 8.1 (2005) was based - in contrast to DR-DOS 8.0 - partly not on previous DR-DOS versions, but on FreeDOS components and had to be withdrawn due to copyright infringements.
The last official version for desktop systems is still the Caldera DR-DOS 7.03 from 1999.
The only publicly accessible further development is currently the Enhanced DR-DOS 7.01.xx, which can be dubbed a fan project, which Udo Kuhnt developed from the published source code of Caldera OpenDOS 7.01. EDR-DOS is subject to the license conditions of the OpenDOS 7.01 source code, which excludes commercial use (except for test purposes).
The DOS-BIOS and BDOS of DR-DOS and practically all resident drivers (especially the memory manager) 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 t