Posts Tagged ‘dOS shell’

DOS Shell

Saturday, May 8th, 2010

The DOS Shell is a file manager, first debuted in MS-DOS and PC-DOS 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 throughout its evolution, but rather an add-on.

While the shell was intended as a graphical alternative to COMMAND.COM, it can run on Windows. However, it does not recognize long filenames and instead truncates the filenames to the 8.3 format. (ie “Homework January 7 2006.doc” becomes “HOMEWO~1.DOC”).

Features
The shell includes common features seen in other file managers such as copying and pasting of files as well as the ability to “launch” applications with a double-click. The shell could be run by the command “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 (GUI) type file manager in DOS, although it is properly referred to as a text user interface (TUI). 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 directory and file lists, i.e. left and right planes. Mouse support was native however, like any other DOS application required an appropriate device driver.

One outstanding feature was its capability of listing 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 redundancies.

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

It required at least 384 kB of the system’s precious conventional memory, leaving little room for other DOS applications or device drivers. The mouse device driver was not a core part of the system and often had to be sourced elsewhere.
It is incapable of multitasking. It could only switch between programs running in memory, and even then the system would still take a significant performance hit. And all the running programs would have to fit into conventional memory.
Windows 3.x was much more popular among computer users. Windows was capable of multitasking, was more stable, possessed a more pleasing interface, system performance was much higher, and had complete access to the system’s Random Access Memory.