What is DOS?

The aim of this article is to give a quick perspective on the evolution of the Operating Systems – and the importance of DOS. DOS – stands for Disk Operating System. The first version of DOS was called PC DOS which was developed by Bill Gates for IBM Computers through his new Microsoft Corporation. The subsequent version was called MS DOS (which stands for Microsoft Disk Operating System) which was later on marketed by Microsoft.

PC DOS and MS DOS are almost identical and both of them were commonly referred to as DOS. DOS is a non-graphical, command line oriented program. It had a simple interface but that was not really user friendly. All commands had to be entered at the C:> (called the C prompt). For most part, a user had to remember the different commands. DOS actually dominated the market between the early ’80s to the mid ’90s.

The first Microsoft Windows Operating system (Windows 3.1) actually ran on DOS – which means, if you wanted to run that version of Windows, your computer should have DOS already installed. Many of the subsequent versions of Windows also actually sat on DOS for example, Windows 95, Windows 98, and Windows ME etc.

But the later versions of Windows which are Windows NT based operating systems like Windows 2000, Windows XP, Windows Vista etc do not make use of MS DOS as a core component of their system. These Operating systems are capable of using the FAT file systems which were used by MS DOS and earlier versions of Windows but by default, they use the NTFS file system.

Given below are some common DOS commands:

Help	Displays list of available commands
xcopy /?	Displays help related to the xcopy command and the correct syntaxes.
prompt $p$g	Make the DOS prompt display the current directory.
time	Displays/Change current system time.
date	Displays/Change current date
cls	Clears the screen
chkdsk	Check disk and memory usage of the current disk.
chkdsk /f	Fix errors reported by chkdsk.
chkdsk file.ext	Check a particular file. eg. file.ext
chkdsk a:	Check a particular drive (in this case, a floppy in the a: drive).
mem	Check memory usage.
ver	Check the version of DOS.
md	Make a directory (folder)
cd	Change a directory
rd	Remove directory
del	Delete
backup c:\ a: /s	Back up the entire c: drive to drive a: .
restore a: c:\ /s	Restore backed-up files and subdirectories from drive a: to c:\
xcopy	Copy all files and sub-directories (you must mention the correct path)
diskcopy a: b:	Duplicate a disk using two floppy drives
diskcopy a: a:	Duplicate a disk using the same floppy drive.
format a: /s	Format disk in a drive and make it bootable