A Complete Guide to MS DOS

MS DOS stands for Microsoft Disk Operating system. While many are used to Windows, a graphical user interface, there was a time when people had to remember the name of commands to get work done. While Windows takes a CD (a DVD in case of Windows 7) for installation, MS DOS can be installed using a single floppy diskette of 3 and half inch (1.44MB).

At the time when Microsoft introduced this easy to use Command Line Interface (CLI) that propelled them in to a famous company, computers were not capable of multi-tasking and handling much memory. Due to these limitations, the MS DOS installation diskette contains only three files: msdos.sys; io.sys, and command.com. While the first two files helped a computer understand its configuration, the command.com file contained commands for the most basic tasks performed on a computer.

An optional file, autoexec.bat contained commands that you wanted to run at computer startup. You can still see this file in many versions of Windows. As the need for more complex tasks arose, MS DOS brought in the facility of using mini-programs called external commands, such as DISKCOPY and FDISK. These external commands were written in MS BASIC, a computer language compatible with MS DOS.