DISK OPERATING SYSTEM (DOS)

INTRODUCTION

DOS is an Operating System. It works as an interpreter between user and computer. We give
English like commands and it converts it into machine language and after the computer has
processed the information, returns the results to you in English. Ms. Dos consist of four essential
programs and a set of additional utilities.

Components of MS-DOS
MS-DOS consists of four essentials programs and a set of additional utilities. Four main
programs are

 Boot Record
 IO.SYS
 MSDOS.SYSTEM
 COMMAND.COM

Booting: Process that starts up a computer is called booting. It checks for proper functioning of
all the peripheral devices attached with the system. It searches for the operating system and,
when located, loads it into the main memory. See fig.01.
Cold Booting is done by turning on the computer.
Warm Booting is performed by pressing Ctrl+Alt+Del keys simultaneously.

There are two name in DOS and is divided into 2 parts.
1. Primary Name
2. Secondary or extension.

Primary name is separated from the Secondary name extension with the help of a dot (.) look at
the following example.

Example: ENVOICE. TXT

Primary name can be from 1 to 8 characters long and
Secondary name contains 3 or less than 3 characters and is optional. The extension tells DOS
about what kind of file it is.

A valid Character for naming a file are: from A to Z and the digit 0 to 9
C :\> Is known as DOS/command prompt, where we give the commands.

DOS command divided into 2 parts.

1. Internal Commands or Memory-Resident Commands
2. External Command or Disk-Residence Commands