[Developer]

What is DOS?


DOS (Disk Operating System) is first operating system release by Microsoft. Before Microsoft; DOS was released by IBM named IBM DOS. Bill Gates started own company Microsoft and released MS DOS 1.0. Before invention GUI Operating System (Windows) DOS’s last version was 6.22. After DOS 6.22 Microsoft never release MS DOS. MS DOS was a simple and command based operating system. There was no use of mouse in MS DOS. All commands were type able from keyboard. Some MS DOS’s famous commands are still in use in Windows Shell (Command Prompt). There were two types of commands in MS DOS.

1. Internal Commands
   
   Internet commands were built in DOS shell commands and do not need any external file. Here are some internal commands. DIRGet the list of files in current folder or directoryCLSClears current working screen of MS DOS)DATEView or change current date of systemTIMEView or change current time of systemREN or RENAMERename a fileCOPYCopy a fileVERGet the current DOS versionMDCreate directory or folderRDRemove directory or folder if empty Note: All internal commands are still supported in Windows Command Prompt.
2. External Commands
   
   External commands were not part of DOS shell and need external files same like Windows Library (DLL) files. Here are some MS DOS’s external commands.
   DELTREERemove folder including all sub folders and filesLABELView or change disk’s label nameFORMATFormat the Hard Disk or Floppy DiskCHKDSKRun disk check on Hard Disk or Floppy Disk