The DOS

DOS

DOS, short for "Disk Operating System", is an acronym for several closely related operating systems that dominated the IBM PC compatible market between 1981 and 1995, or until about 2000 if one includes the partially DOS-based Microsoft Windows versions 95, 98, and Millennium Edition.Related...

 Shell is a file manager

File manager

A file manager or file browser is a computer program that provides a user interface to work with file systems. The most common operations performed on files or groups of files are: create, open, edit, view, print, play, rename, move, copy, delete, search/find, and modify file attributes, properties...

, debuted in MS-DOS

MS-DOS

MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...

 and IBM DOS (PC DOS)

PC-DOS

IBM PC DOS is a DOS system for the IBM Personal Computer and compatibles, manufactured and sold by IBM from the 1980s to the 2000s....

 4.0 (June 1988). It was discontinued after version 6.0, but retained as part of the "Supplemental Disk" until 6.22 for MS-DOS; as such, it was not a core part of the operating system

Operating system

An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

 throughout its evolution, but rather an add-on

Add-on

Add-on might mean:* Plug-in , a piece of software which enhances another software application and usually cannot be run independently** Browser extension, which modifies the interface and/or behavior of web browsers...

. It was, however, retained in IBM DOS and PC DOS through PC DOS 2000.

Features

The shell includes common features seen in other file managers such as copying, moving and renaming files as well as the ability to "launch" applications with a double-click. The shell could be run by the command

Command (computing)

In computing, a command is a directive to a computer program acting as an interpreter of some kind, in order to perform a specific task. Most commonly a command is a directive to some kind of command line interface, such as a shell....

 "dosshell". It had the ability to set simple colours and styles. The shell was one of the first successful attempts to create a basic graphical user interface

Graphical user interface

In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

 (GUI) type file manager in DOS, although it is properly referred to as a text user interface

Text user interface

TUI short for: Text User Interface or Textual User Interface , is a retronym that was coined sometime after the invention of graphical user interfaces, to distinguish them from text-based user interfaces...

 (TUI) or Character Oriented Window (COW) even though graphical modes were available on supported hardware (VGA equipped PCs). The shell is very much like a DOS version of Windows File Manager.

The shell also has a help system, "program list", and a "task swapper". Like modern file managers it had the ability to display dual hierarchy

Hierarchy

A hierarchy is an arrangement of items in which the items are represented as being "above," "below," or "at the same level as" one another...

 directory and file lists, i.e. left and right panes

Paned window

A paned window is a window that is divided into sections known as panes. Originally, the meaning pertained to sectioned glass windows in walls.Computer scientists have adopted the term "pane" to refer to parts of sectioned windows on a graphical display...

. The mouse was supported, however, like any other DOS application, it required an appropriate device driver

Device driver

In computing, a device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device....

.

One feature was the ability to list all files on a hard drive in a single alphabetized list along with the path and other attributes. This permitted the user to compare versions of a file in different directories by their attributes and easily spot duplicates.

Problems

There are several reasons why the shell fell out of use:

• It was incapable of multitasking
  Computer multitasking
  In computing, multitasking is a method where multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for...
  
  , but did support rudimentary task switching. It could switch between programs running in memory, and even then the system would still take a significant performance hit. All the running programs had to fit into conventional memory, as there was no support for paging
  Paging
  In computer operating systems, paging is one of the memory-management schemes by which a computer can store and retrieve data from secondary storage for use in main memory. In the paging memory-management scheme, the operating system retrieves data from secondary storage in same-size blocks called...
  
   to disk.
• Windows 3.x
  Windows 3.1x
  Windows 3.1x is a series of 16-bit operating systems produced by Microsoft for use on personal computers. The series began with Windows 3.1, which was first sold during March 1992 as a successor to Windows 3.0...
  
  , with its own graphical user interface, became much more popular among computer users. Windows was capable of multitasking. System performance was much higher, with complete access to the system's RAM.