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Wikipedia
In computing, a window is a graphical control element. It consists of a visual area containing some of the graphical user interface of the program it belongs to and is framed by a window decoration. It usually has a rectangular shape that can overlap with the area of other windows. It displays the output of and may allow input to one or more processes.
Windows are primarily associated with graphical displays, where they can be manipulated with a pointer by employing some kind of pointing device. Text-only displays can also support windowing, as a way to maintain multiple independent display areas, such as multiple buffers in Emacs. Text windows are usually controlled by keyboard, though some also respond to the mouse.
A graphical user interface (GUI) using windows as one of its main “metaphors” is called a windowing system, whose main components are the display server and the window manager.
The idea was developed at the Stanford Research Institute (led by Douglas Engel bart). Their earliest systems supported multiple windows, but there was no obvious way to indicate boundaries between them (such as window borders, title bars, etc.).
Research continued at Xerox Corporation’s Palo Alto Research Center / PARC (led by Alan Kay). They used overlapping windows.
During the 1980s the term “WIMP”, which stands for window, icon, menu, pointer, was coined at PARC.
Apple had worked with PARC briefly at that time. Apple developed an interface based on PARC’s interface. It was first used on Apple’s Lisa and later Macintosh computers. Microsoft was developing Office applications for the Mac at that time. Some speculate that this gave them access to Apple’s OS before it was released and thus influenced the design of the windowing system in what would eventually be called Microsoft Windows.
Windows are two dimensional objects arranged on a plane called the desktop metaphor. In a modern full-featured windowing system they can be resized, moved, hidden, restored or closed.
Windows usually include other graphical objects, possibly including a menu-bar, toolbars, controls, icons and often a working area. In the working area, the document, image, folder contents or other main object is displayed. Around the working area, within the bounding window, there may be other smaller window areas, sometimes called panes or panels, showing relevant information or options. The working area of a single document interface holds only one main object. “Child windows” in multiple document interfaces, and tabs for example in many web browsers, can make several similar documents or main objects available within a single main application window. Some windows in Mac OS X have a feature called a drawer, which is a pane that slides out the side of the window and to show extra options.
Applications that can run either under a graphical user interface or in a text user interface may use different terminology. GNU Emacs uses the term ‘window’ to refer to an area within its display while a traditional window, such as controlled by an X11 window manager, is called a ‘frame’.
Any window can be split into the window decoration and the window’s content, although some systems purposely eschew window decoration as a form of minimalism.
The window decoration is a part of a window in most windowing systems.
A windows decoration typically consists of a title bar, usually along the top of each window and a minimal border around the other three sides. On Microsoft Windows this is called “non-client area”.
In the predominant layout for modern window decorations, the top bar contains the title of that window and buttons which perform windowing-related actions such as:
- Close
- Maximize
- Minimize
- Resize
- Roll-up
The border exists primarily to allow the user to resize the window, but also to create a visual separation between the window’s contents and the rest of the desktop environment.
Window decorations are considered important for the design of the look and feel of an operating system and some systems allow for customization of the colors, styles and animation effects used.
DOS (/dɒs/, /dɔːs/) is a platform-independent acronym for “disk operating system” that later became a common shorthand for disk-based operating systems on IBM PC compatibles. DOS primarily consists of Microsoft’s MS-DOS and a rebranded version under the name IBM PC DOS, both of which were introduced in 1981. Later compatible systems from other manufacturers include DR DOS (1988), ROM-DOS (1989), PTS-DOS (1993), and Free DOS (1998). MS-DOS dominated the IBM PC compatible market between 1981 and 1995.
Dozens of other operating systems also use the acronym “DOS”, beginning with the mainframe DOS/360 from 1966. Others include Apple DOS, Apple Pro DOS, Atari DOS, Commodore DOS, TRS DOS, and Amiga DOS.
IBM PC DOS (and the separately sold MS-DOS) and its predecessor, 86-DOS, was developed to be similar to Digital Research’s CP/M—the dominant disk operating system for 8-bit Intel 8080 and Zilog Z80 microcomputers—but instead ran on Intel 8086 16-bit processors, in order to easily port CP/M applications to MS-DOS.
When IBM introduced the IBM PC, built with the Intel 8088 microprocessor, they needed an operating system. Seeking an 8088-compatible build of CP/M, they initially approached IBM board member Mary Maxwell Gates’ son, Bill Gates. IBM was then sent to Digital Research, and a meeting was set up. However, initial negotiations for the use of CP/M broke down: Digital Research wished to sell CP/M on a royalty basis, while IBM sought a single license, and to change the name to “PC DOS”. Digital Research founder Gary Kildall refused, and IBM withdrew.
IBM again approached Bill Gates. Gates in turn approached Seattle Computer Products. There, programmer Tim Paterson had developed a variant of CP/M-80, intended as an internal product for testing SCP’s new 16-bit Intel 8086 CPU card for the S-100 bus. The system was initially named QDOS (Quick and Dirty Operating System), before being made commercially available as 86-DOS. Microsoft purchased 86-DOS, allegedly for US$50,000. This became Microsoft Disk Operating System, MS-DOS, introduced in 1981. Within a year Microsoft licensed MS-DOS to over 70 other companies, which supplied the operating system for their own hardware, sometimes under their own names. Microsoft later required the use of the MS-DOS name, with the exception of the IBM variant. IBM continued to develop their version, PC DOS, for the IBM PC. Digital Research became aware that an operating system similar to CP/M was being sold by IBM (under the same name that IBM insisted upon for CP/M), and threatened legal action. IBM responded by offering an agreement: they would give PC consumers a choice of PC DOS or CP/M-86, Kildall’s 8086 version. Side-by-side, CP/M cost US$200 more than PC DOS, and sales were low. CP/M faded, with MS-DOS and PC DOS becoming the marketed operating system for PCs and PC compatibles.
Microsoft originally sold MS-DOS only to original equipment manufacturers (OEMs). One major reason for this was that not all early PCs were 100% IBM PC compatible. DOS was structured such that there was a separation between the system specific device driver code (IO.SYS) and the DOS kernel (MSDOS.SYS). Microsoft provided an OEM Adaptation Kit (OAK) which allowed OEMs to customize the device driver code to their particular system. By the early 1990s, most PCs adhered to IBM PC standards so Microsoft began selling MS-DOS in retail with MS-DOS 5.0.
In the mid-1980s Microsoft developed a multitasking version of DOS. This version of DOS is generally referred to as “European MS-DOS 4” because it was developed for ICL and licensed to several European companies. This version of DOS supports preemptive multitasking, shared memory, device helper services and New Executable (“NE”) format executables. None of these features were used in later versions of DOS, but they were used to form the basis of the OS/2 1.0 kernel. This version of DOS is distinct from the widely released PC DOS 4.0 which was developed by IBM and based upon DOS 3.3.
Digital Research attempted to regain the market lost from CP/M-86, initially with Concurrent DOS, Flex OS and DOS Plus (both compatible with both MS-DOS and CP/M-86 software), later with Multi user DOS (compatible with both MS-DOS and CP/M-86 software) and DR DOS (compatible with MS-DOS software). Digital Research was bought by Novell, and DR DOS became Palm DOS and Novell DOS; later, it was part of Caldera (under the names Open DOS and DR-DOS 7.02/7.03), Lineo, and Device Logics.
Gordon Letwin wrote in 1995 that “DOS was, when we first wrote it, a one-time throw-away product intended to keep IBM happy so that they’d buy our languages”. Microsoft expected that it would be an interim solution before Xenix. The company planned to improve MS-DOS over time, so it would be almost indistinguishable from single-user Xenix, or XEDOS, which would also run on the Motorola 68000, Zilog Z-8000, and LSI-11; they would be upwardly compatible with Xenix, which BYTE in 1983 described as “the multi-user MS-DOS of the future”.
IBM, however, did not want to replace DOS. After AT&T began selling Unix, Microsoft and IBM began developing OS/2 as an alternative. The two companies later had a series of disagreements over two successor operating systems to DOS, OS/2 and Windows. They split development of their DOS systems as a result. The last retail version of MS-DOS was MS-DOS 6.22; after this, MS-DOS became part of Windows 95, 98 and Me. The last retail version of PC DOS was PC DOS 2000 (also called PC DOS 7 revision 1), though IBM did later develop PC DOS 7.10 for OEMs and internal use.
The Free DOS project began on 26 June 1994, when Microsoft announced it would no longer sell or support MS-DOS. Jim Hall then posted a manifesto proposing the development of an open-source replacement. Within a few weeks, other programmers including Pat Villani and Tim Norman joined the project. A kernel, the COMMAND.COM command line interpreter (shell), and core utilities were created by pooling code they had written or found available. There were several official pre-release distributions of Free DOS before the Free DOS 1.0 distribution was released on 3 September 2006. Made available under the GNU General Public License (GPL), Free DOS does not require license fees or royalties.
This article presents a list of commands used by DOS operating systems, especially as used on x86-based IBM PC compatibles (PCs). Other DOS operating systems are not part of the scope of this list.
In DOS, many standard system commands were provided for common tasks such as listing files on a disk or moving files. Some commands were built into the command interpreter, others existed as external commands on disk. Over the several generations of DOS, commands were added for the additional functions of the operating system. In the current Microsoft Windows operating system, a text-mode command prompt window, cmd.exe, can still be used.
The command interpreter for DOS runs when no application programs are running. When an application exits, if the transient portion of the command interpreter in memory was overwritten, DOS will reload it from disk. Some commands are internal—built into COMMAND.COM; others are external commands stored on disk. When the user types a line of text at the operating system command prompt, COMMAND.COM will parse the line and attempt to match a command name to a built-in command or to the name of an executable program file or batch file on disk. If no match is found, an error message is printed, and the command prompt is refreshed.
External commands were too large to keep in the command processor, or were less frequently used. Such utility programs would be stored on disk and loaded just like regular application programs but were distributed with the operating system. Copies of these utility command programs had to be on an accessible disk, either on the current drive or on the command path set in the command interpreter.
In the list below, commands that can accept more than one file name, or a filename including wildcards (* and ?), are said to accept a file spec (file specification) parameter. Commands that can accept only a single file name are said to accept a filename parameter. Additionally, command line switches, or other parameter strings, can be supplied on the command line. Spaces and symbols such as a “/” or a “-” may be used to allow the command processor to parse the command line into filenames, file specifications, and other options.
The command interpreter preserves the case of whatever parameters are passed to commands, but the command names themselves and file names are case-insensitive.
Many commands are the same across many DOS systems, but some differ in command syntax or name.
A partial list of the most common commands for MS-DOS and IBM PC DOS follows below.
Sets the path to be searched for data files or displays the current search path. The APPEND command is similar to the PATH command that tells DOS where to search for program files (files with a .COM, . EXE, or .BAT file name extension).
The command is available in MS-DOS versions 3.2 and later.
The command redirects requests for disk operations on one drive to a different drive. It can also display drive assignments or reset all drive letters to their original assignments.