Archive for DOS

DOS – DISK OPERATING SYSTEM

DOS (Disk Operating System) was the first widely-installed operating system for personal computers. (Earlier, the same name had been used for an IBM operating system .)

The first personal computer version of DOS, called PC-DOS, was developed for IBM by Bill Gates and his new Microsoft Corporation. He retained the rights to market a Microsoft version, called MS-DOS. PC-DOS and MS-DOS are almost identical and most users have referred to either of them as just “DOS.” DOS was (and still is) a non-graphical line-oriented command- operating system, with a relatively simple interface but not overly “friendly” user interface. Its prompt to enter a command looks like this:

C:>

The first Microsoft Windows operating system was really an application that ran on top of the MS-DOS operating system. Today, Windows operating systems continue to support DOS (or a DOS-like user interface) for special purposes.

MS-DOS

Short for Microsoft Disk operating system, MS-DOS is a non-graphical command line operating system derived from 86-DOS that was created for IBM compatible computers. MS-DOS originally written by Tim Paterson and introduced by Microsoft in August 1981 and was last updated in 1994 when MS-DOS 6.22 was released. Today, MS-DOS is no longer used; however, the command shell, more commonly known as the Windows command line is still used by many users. In the picture to the right, is an example of what a MS-DOS window more appropriately referred to as the Windows command line looks like under Microsoft Windows.

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

  1.  Boot Record
  2.  IO.SYS
  3.  MSDOS.SYST
  4.  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.

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