DESQview
Encyclopedia
DESQview was a text mode
Text mode
Text mode is a kind of computer display mode in which the content of the screen is internally represented in terms of characters rather than individual pixels. Typically, the screen consists of a uniform rectangular grid of character cells, each of which contains one of the characters of a...

 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...

 program developed by Quarterdeck Office Systems
Quarterdeck Office Systems
Quarterdeck Office Systems, later Quarterdeck Corporation , was an American computer software company. It was founded by Therese Myers and Gary Pope in 1981and incorporated in 1982...

 which enjoyed modest popularity in the late 1980s and early 1990s. Running on top of 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...

, it allowed users to run multiple DOS programs concurrently in multiple windows
Window (computing)
In computing, a window is a visual area containing some kind of user interface. It usually has a rectangular shape that can overlap with the area of other windows...

.

DESQ

Quarterdeck's predecessor to DESQview was a task switching
Context switch
A context switch is the computing process of storing and restoring the state of a CPU so that execution can be resumed from the same point at a later time. This enables multiple processes to share a single CPU. The context switch is an essential feature of a multitasking operating system...

 product called DESQ which allowed users to switch between running programs. It was not very popular, and the task-switching market was primarily dominated by Software Carousel, a product with limited windowing capabilities. Quarterdeck revamped its package, bringing multitasking in, and adding TopView compatibility; it was renamed DESQview.

DESQview

DESQview was released in July 1985, four months before Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

 introduced the first version of Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

. It was widely thought to be the first program to bring multitasking and windowing capabilities to DOS, but in fact there was a predecessor, IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

's TopView
TopView
TopView is a text-mode PC DOS multitasking, object oriented windowing environment written by IBM and introduced in August of 1984 and made available in February of 1985. TopView was announced in order to provide an environment that users could run more than one application at the same time on a PC...

, released in 1984, from which DESQview inherited the popup menu.

Under DESQview, well-behaved DOS programs could be run concurrently in resizable, overlapping windows (something the first version of Windows could not do). A simple hidable menu allowed cutting and pasting between programs. DESQview provided support for simple editable macros as well. Quarterdeck also developed a set of optional utilities for DESQview, including a notepad and dialer. Later versions allowed graphics mode programs to be loaded as well, but only run in full screen mode.

DESQview was not a full-fledged GUI
Gui
Gui or guee is a generic term to refer to grilled dishes in Korean cuisine. These most commonly have meat or fish as their primary ingredient, but may in some cases also comprise grilled vegetables or other vegetarian ingredients. The term derives from the verb, "gupda" in Korean, which literally...

 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...

; it was a quasi-GUI shell that ran in real mode
Real mode
Real mode, also called real address mode, is an operating mode of 80286 and later x86-compatible CPUs. Real mode is characterized by a 20 bit segmented memory address space and unlimited direct software access to all memory, I/O addresses and peripheral hardware...

 on top of DOS. Although it could run on any Intel 8086
Intel 8086
The 8086 is a 16-bit microprocessor chip designed by Intel between early 1976 and mid-1978, when it was released. The 8086 gave rise to the x86 architecture of Intel's future processors...

- or Intel 80286
Intel 80286
The Intel 80286 , introduced on 1 February 1982, was a 16-bit x86 microprocessor with 134,000 transistors. Like its contemporary simpler cousin, the 80186, it could correctly execute most software written for the earlier Intel 8086 and 8088...

-based PC, it really came into its own on Intel 80386
Intel 80386
The Intel 80386, also known as the i386, or just 386, was a 32-bit microprocessor introduced by Intel in 1985. The first versions had 275,000 transistors and were used as the central processing unit of many workstations and high-end personal computers of the time...

 machines which were better at utilizing memory above DOS's limit of 640 KB. However, in either case, it ran in real mode rather than protected mode
Protected mode
In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units...

, meaning that a misbehaving program could still crash the system.

DESQview and QEMM

To make maximum use of extended memory
Extended memory
In DOS memory management, extended memory refers to memory above the first megabyte of address space in an IBM PC or compatible with an 80286 or later processor. The term is mainly used under the DOS and Windows operating systems...

 on Intel 80386
Intel 80386
The Intel 80386, also known as the i386, or just 386, was a 32-bit microprocessor introduced by Intel in 1985. The first versions had 275,000 transistors and were used as the central processing unit of many workstations and high-end personal computers of the time...

 processors, by transforming it into expanded memory
Expanded memory
In DOS memory management, expanded memory is a system of bank switching introduced April 24, 1985 that provided additional memory to DOS programs beyond the limit of conventional memory. Expanded memory uses parts of the address space normally dedicated to communication with peripherals for program...

 and upper memory blocks (UMB
Upper Memory Area
In DOS memory management, the upper memory area refers to memory between the addresses of 640 KB and 1024 KB in an IBM PC or compatible. IBM reserved the uppermost 384 KB of the 8088 CPU's 1024 KB address space for ROM, RAM on peripherals, and memory-mapped input/output...

s) accessible to DESQview and other real-mode programs, Quarterdeck developed a sophisticated memory manager
Memory manager
In IBM PC compatible computing, DOS memory management refers to software and techniques employed to give applications access to more than 640K of "conventional memory". The 640kB limit was specific to the IBM PC and close compatibles; other machines running MS-DOS had different limits, for example...

. Owing to the foresight of its marketing manager, Quarterdeck marketed it as a separate product, QEMM-386 (Quarterdeck Expanded Memory Manager 386). It became more popular than DESQview itself, and sold steadily for many years, generating over US$150 million in sales from 1987 through 1994. After the release of the Intel Pentium processor, the 386 in QEMM was dropped. The combination package of DESQview and QEMM-386 was called DESQview 386.

With the introduction of the 80386, the memory management features were enhanced to allow the system to be shifted into protected mode but also allowing the addresses to be configured in a virtual 8086 mode
Virtual 8086 mode
In the 80386 microprocessor and later, virtual 8086 mode allows the execution of real mode applications that are incapable of running directly in protected mode while the processor is running a protected mode operating system.VM86 mode uses a segmentation scheme identical to that of real mode In...

 so that the extended memory could be mapped into addressing frames and accessible to real-mode programs such as MS-DOS. This allowed a 386 to implement the LIM (Lotus
Lotus Software
Lotus Software is a software company with headquarters in Westford, Massachusetts...

, Intel, Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

) EMS (expanded memory specification). The memory manager was easily controlled by the user with DOS program QEMM.COM

DESQview was able to use QEMM's features far beyond just the LIM EMS API, mapping most of the "conventional" address space (below 640 KB) into multiple extended memory blocks such that each could execute transparently during its context. The main copy of DOS and any device and networking drivers had to be loaded before DESQview. The resulting space was the largest single program that could run, but DESQview under QEMM could run as many instances of those programs as the EMS would allow. So an 8 MB system could generally have a dozen full-sized MS-DOS programs running concurrently; a 16 MB system could run over twenty, and so on.

DESQview usage

DESQview was noteworthy in that it supported all common DOS-compatible programs and achieved a degree of performance and stability that was remarkable, given the constraints of its host operating system. It also had a clever interface that was generally unobtrusive while being quickly available and very easy to learn.

All normal PCs include a keyboard with three "shift" or "modifier" keys: Control, Alt, and the normal Shift keys. These keys are normally held down in combination with other keys. DESQview, by default, monitored the Alt key for isolated presses (not in combination). Pressing the Alt key by itself would bring up the DESQview menu allowing access to the program's features: start new tasks, switch among them, mark text on the screen, paste text as input into the current task, resize or move the text windows, configure new menu items, etc. In addition a Shift+Alt combination would cause DESQview to learn a set of keys as a macro. This allowed DESQview to run other programs without interfering with any of the "keybindings" they might be using.

DESQview was critically acclaimed and won many fans, but it never met with mass appeal, despite Quarterdeck's sustained efforts to win people over. Reportedly it intrigued many people at Microsoft, including Bill Gates
Bill Gates
William Henry "Bill" Gates III is an American business magnate, investor, philanthropist, and author. Gates is the former CEO and current chairman of Microsoft, the software company he founded with Paul Allen...

, who by some accounts based his first version of Windows on DESQview and two other early GUIs, Visi On
Visi On
VisiCorp's Visi On was a short-lived but influential graphical user interface-based operating environment program for IBM PC compatible personal computers running early versions of DOS...

 and GEM
Graphical Environment Manager
GEM was a windowing system created by Digital Research, Inc. for use with the CP/M operating system on the Intel 8088 and Motorola 68000 microprocessors...

.

In one area, however, DESQview was a lasting success: many multiuser bulletin board system
Bulletin board system
A Bulletin Board System, or BBS, is a computer system running software that allows users to connect and log in to the system using a terminal program. Once logged in, a user can perform functions such as uploading and downloading software and data, reading news and bulletins, and exchanging...

s were based on it, thanks to its modest hardware requirements, robust multitasking, and superlative handling of multiple communication ports. Most free or inexpensive BBS software of the time ran as a single-node, single-tasking DOS program. Normally, only one copy of the BBS software could run at once, limiting the host PC to running one node. DESQview allowed multiple copies of these single-task programs to run at once on the same computer, allowing anyone with even unimpressive hardware to run a large, powerful, multiuser BBS out of their home.

Decline of DESQview

DESQview did not provide a graphical user interface (GUI
Gui
Gui or guee is a generic term to refer to grilled dishes in Korean cuisine. These most commonly have meat or fish as their primary ingredient, but may in some cases also comprise grilled vegetables or other vegetarian ingredients. The term derives from the verb, "gupda" in Korean, which literally...

). While Quarterdeck did provide suites of programming libraries and utilities to support the development of software to use its features these never became widely popular. (DESQview's ability to run most software with no modification and the cost of "run-time" licenses, combined with the costs of the development suites themselves made this an unreasonable combination for commercial shrink-wrapped software publishers and vendors.)

Microsoft released Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 version 3.0 with its own memory management and multitasking features. While DESQview was far faster, smaller, and more stable, it was more expensive and didn't include support for the graphical features of MS Windows.

The decline of QEMM started with the bundling of a memory manager in Digital Research
Digital Research
Digital Research, Inc. was the company created by Dr. Gary Kildall to market and develop his CP/M operating system and related products. It was the first large software company in the microcomputer world...

's DR DOS
DR-DOS
DR-DOS is an MS-DOS-compatible operating system for IBM PC-compatible personal computers, originally developed by Gary Kildall's Digital Research and derived from Concurrent PC DOS 6.0, which was an advanced successor of CP/M-86...

 5.0, released in 1990. To catch on, Microsoft included its own EMM386
EMM386
The name EMM386 was used for the expanded memory managers of both Microsoft's MS-DOS and Digital Research's DR-DOS, which created expanded memory using extended memory on Intel 80386 CPUs. There also is an EMM386.EXE available in FreeDOS....

 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...

 5.0, while previously the memory management functionality was only available with Windows. QEMM could still be used instead, notably with Windows 3.1x
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...

, but it only provided incremental benefits. Sales of QEMM declined. In August 1994, after three quarters of losses, the company laid off 25% of their employees and the CEO, president, and founder Terry Myers resigned.

As users moved from DESQview to other platforms, notably Windows 3.x and OS/2, third party utility authors wrote utility programs that emulated some DESQview API functions to allow suitably equipped DOS programs to co-operate with these OS. The most notable were TAME (for Windows), and OS/2SPEED (for OS/2)

DESQview/X

Quarterdeck eventually also released a product named DESQview/X, which was an X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...

 server running under MS-DOS and DESQview and thus provided a GUI to which X software (mostly Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...

) could be ported. However, by the time this was released there were far too many applications available for MS Windows, X Window System software was either generally free (non-commercial) or very expensive, and was designed to perform well on graphical Unix workstations with performance beyond that of PC compatible machines of the time. Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

 was also becoming available, and eventually provided a robust operating system, X server, and a UNIX-compatible API. In other words, DESQview/X was in far too small a niche.

DESQview/X had three window managers that it launched with, X/Motif
Motif Window Manager
In computing, the Motif Window Manager is an X window manager based on the Motif toolkit.MWM is a lightweight and, by today's standards, extremely minimalist window manager. MWM lacks support for desktop icons or virtual desktops. A plain text file is used to generate a root menu that the user can...

, OPEN LOOK
OPEN LOOK
OPEN LOOK is a graphical user interface specification for UNIX workstations. It was originally defined in the late 1980s by Sun Microsystems and AT&T.-History:...

, and twm
Twm
In computing, twm is the standard window manager for the X Window System, version X11R4 onwards...

. The default package contained only twm, the others were costly optional extras, as was the ability to interact on TCP/IP networks. Mosaic
Mosaic (web browser)
Mosaic is the web browser credited with popularizing the World Wide Web. It was also a client for earlier protocols such as FTP, NNTP, and gopher. Its clean, easily understood user interface, reliability, Windows port and simple installation all contributed to making it the application that opened...

 was ported to DVX.

DVX itself could serve 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...

 programs and the 16-bit Windows environment across the network as X programs, which made it useful for those who wished to run MS-DOS and MS Windows programs from their Unix workstations. The same functionality was once available with NCD
Network Computing Devices
Network Computing Devices was a company founded in 1987 to produce a new class of products now known as a "thin client". It was founded in Mountain View, CA, and when it closed it was headquartered in Portland, Oregon....

 Wincenter.

NetWare Access Server

Internetworking company Novell
Novell
Novell, Inc. is a multinational software and services company. It is a wholly owned subsidiary of The Attachmate Group. It specializes in network operating systems, such as Novell NetWare; systems management solutions, such as Novell ZENworks; and collaboration solutions, such as Novell Groupwise...

 developed a product called Netware Access Server incorporating features of DESQview 386 and pcAnywhere
PcAnywhere
pcAnywhere is a suite of computer programs by Symantec which allows a user of the pcAnywhere remote program on a computer to connect to a personal computer running the pcAnywhere host if both are connected to the internet or the same LAN and the password is known...

. The DESQview multitasking support was used to create an environment into which up to 16 PC and Macintosh clients could login remotely to access NetWare services and run DOS applications.

DESQview after X

DESQview development continued in parallel with DESQview/X. After ceasing development on DESQview/X, another version of DESQview was released. QEMM was still developed after the discontinuation of DESQview, and a version compatible with Windows 98
Windows 98
Windows 98 is a graphical operating system by Microsoft. It is the second major release in the Windows 9x line of operating systems. It was released to manufacturing on 15 May 1998 and to retail on 25 June 1998. Windows 98 is the successor to Windows 95. Like its predecessor, it is a hybrid...

 was released.

In the mid 1990s, Quarterdeck tried to recast itself as an Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

 company, releasing a version of the Mosaic web browser. Eventually, the company was acquired by Symantec
Symantec
Symantec Corporation is the largest maker of security software for computers. The company is headquartered in Mountain View, California, and is a Fortune 500 company and a member of the S&P 500 stock market index.-History:...

.

Free? public release

The DESQview packages have been available for download on the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

 for a few years on at least one stable site (listed below) with no trace of complaint, however neither the host site CharterSoft nor Symantec
Symantec
Symantec Corporation is the largest maker of security software for computers. The company is headquartered in Mountain View, California, and is a Fortune 500 company and a member of the S&P 500 stock market index.-History:...

's corporate counsel will clarify copyright status on direct request.

Quarterdeck's shrinkwrap licence for DESQview, QEMM and their other products was unusual in being time-limited, giving permission to use the product for only twenty to thirty years.

Claims that the software is "public domain" are unsubstantiated and appear to be based solely on an editor statement in this Slashdot Article from 2002.

On August 21, 2001, a newsgroup posting reinforced the idea that DESQview is property of Symantec, although they may not realize it.

External links and further reading

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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