According to ABBREVIATIONFINDER.ORG, DOS is an acronym for D isk O perating S ystem, famila of operating systems for PCs. Originally created for computers in the IBM PC family, which used the 16-bit Intel 8086 and 8088 processors, being the first popular operating system for this platform. He had an interface of command line in text mode or alphanumeric and its own command interpreter (or orders) the command.com. The most popular of its variants is MS-DOS (created by Microsoft, and that most PC computers have installed.) but the family includes QDOS, PC-DOS, DR-DOS, Novell DOS, FreeDOS, DOSBox, Apple DOS and Atari DOS.
More than an operating system
The DOS is in addition to an operating system is a set of programs that allow us to manipulate information contained in disks, to work with ease, comfort and speed with them; in addition, DOS coordinates the operation of the microprocessor.
Microsoft has been improving DOS since its first version in 1981. The versions that may exist are used to correct errors detected in the previous version or to improve certain parts of the program.
DOS Features
- It completely lacks a graphical interface.
- It does not use the mouse.
- By itself it is incapable of detecting hardware, unless the drivers are included in its core system, as memory residents, the necessary code, instructions and functions.
- It is neither multiuser or multitasking (not can work with more than one user or more than one process at a time).
- In its native versions (up to 6.22 in MS-DOS), it cannot work with disk partitions larger than 2 GB, which require formats and file systems such as FAT32, typical of 32-bit Windows (as of 95), or the NTFS, typical of Windows of type NT.
- Due to software limitations (initially), it could not handle more than 64 KB of RAM. In versions prior to 4.0, the limit, in turn, was 32 MB per partition, as the FAT16 format (developed in 1987) is not yet supported.
- Until the appearance of DirectX, and in order to take full advantage of the hardware, most PC video games ran directly under DOS.
- In the 32-bit Windows operating environments, until 98, they had DOS as a camouflaged or hidden base platform.
DOS versions
Several companies released versions of DOS, very similar to each other like PC-DOS and MS-DOS that started out almost identical, although they ended up being very different.
The best known versions have been:
- QDOS (written by Tim Paterson) (Seattle Computer Products) (1979). QDOS (acronym Q uick and D IRTY O perating S ystem which translates into Spanish as OS Quick and Dirty) was a purchased operating system by Microsoft to the company Seattle Computer and served to create the basis of what later it would be PC-DOS and MS-DOS.
- Microsoft’s MS-DOS (1981). PC operating system created by the Microsoft company from QDOS and used in its early days mainly by computers manufactured by IBM. Its name is obtained from the acronym in English: M icro S oft D isk Operating S ystem which translates in Spanish as (Microsoft Disk Operating System).
- PC-DOS from IBM (1981)
- DR-DOS by Digital Research) (1988)
- Novell DOS (Novell) (1991)
- FreeDOS (Jim Hall & The FreeDOS team) (1994). It is a DOS compatible operating system for IBM / PC compatible systems. It is made up of many different and separate programs, which act as “packages” to encompass the FreeDOS project.
- DOSBox (emulator).
- Apple DOS from Apple.
- Atari DOS from Atari.
Under GNU / Linux it is possible to run copies of DOS under dosemu, a native Linux virtual machine to run programs in real mode. There are many other emulators for different versions of UNIX, even for platforms other than the x86 processor architecture.
MS-DOS and Windows
Non-native versions of Windows are based on MS-DOS and MS-DOS was loaded from the latter. Windows was a simple graphical interface application, complementary to the command interpreter itself, from which it was run from Windows 1.0xto Windows 3.1x 16-bit versions.
In Windows 95 and 98 (32-bit versions), MS-DOS began to be camouflaged by Windows’ own graphical environment, during the boot process, giving way to its automatic execution, becoming by many forgotten and unknown, and gradually abandoned by software and hardware developers, including Microsoft itself.
In the versions based on NT (Windows NT, 2000, XP, Vista and Windows 7) MS-DOS disappears as an operating system (properly speaking) and base environment, from which the computer and its basic processes are started and proceeded to execute and load the graphical interface or Windows operating environment. All vestige of it is relegated, in such versions, to the existence of a simple command interpreter, called the command prompt, executed as an application using cmd.exe, from the graphical environment itself, now elevated to the category of system.
