MS-DOS Operating System Most Personal Computers run under the MS-DOS Operating System. MS-DOS being the Microsoft Disk Operating System.
It is estimated that almost 10 million machines run under the MS-DOS Operating System and some 20,000 or more end-user applications have been published to run with it.
The Operating System is the program which provides organized services to the computer user and the application programs that they wish to use.
These services consist mainly of access to the hardware resources such as the disk drives, keyboard, etc.
The Operating System has three main constituents:-
1. The system files which are hidden. Their function is to perform such basic tasks as reading the keyboard, displaying characters on the screen, opening and closing files etc.
2. The command interrupter, COMMAND.COM which reads commands typed at the keyboard and attempts to obey them. COMMAND.COM has some simple commands built in – these are known as internal commands.
3. A series of utility programs covering functions not handled by the internal commands. There are approximately 52 of these commands; the exact number varies between different versions of MS-DOS, ranging from COPY to copy files to EDIT the text editor, and much more.
Therefore, the Operating systems provide a software platform on top of which other programs, called application programs, can run.
The application programs must be written to run on top of a particular operating system. Our choice of operating system, therefore, determines to a great extent the applications we can run.
For PCs, the most popular operating systems are DOS, OS/2, and Windows, but others are available, such as Linux.