Theory - 94 :- DOS ( Disk Operating System)

 

Introduction:

DOS (Disk Operating System) is an oldest type of Operating System. Disk Operating  System is abbreviated as DOS. DOS is a CUI type of Operating System. In computer science, a generic term describing any operating system is system software which is loaded from disk devices when the system is started or rebooted. DOS is a single-tasking, single-user operating system with a command-line interface.

DOS acts on commands. Because DOS is ready to perform when given proper command hence, it is also known as Command Prompt.

Commands are certain words of English language or short form of English words. The meaning of these word or short form is already known to DOS. Since, DOS recognized these words and hence acts accordingly. These words and short forms of the English words are better known as commands.

• Internal Command:-Those commands which are already stored in the “Command.Com” file of DOS are known as internal commands. For example, CLS, VOL, TIME, DATE, COPY etc
• External Command:-Those commands which are not included in the command.com file of DOS rather included in other files of DOS are known as external commands. It is formatted according to programmed. For example, TREE, FORMAT, MODE etc