DESQview (DV) is a

text mode Text mode is a computer display mode in which content is internally represented on a computer screen in terms of characters rather than individual pixels. Typically, the screen consists of a uniform rectangular grid of ''character cells'', each ...

operating environment In computer software, an operating environment or integrated applications environment is the environment in which users run application software. The environment consists of a user interface provided by an applications manager and usually an app ...

developed by

Quarterdeck Office Systems Quarterdeck Office Systems, later Quarterdeck Corporation (NASDAQ: QDEK), was an American computer software company. It was founded by Therese Myers and Gary Pope in 1981 and incorporated in 1982. Their offices were initially located at 150 Pico B ...

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

DOS DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems. DOS may also refer to: Computing * Data over signalling (DoS), multiplexing data onto a signalling channel * Denial-of-service attack (DoS), an attack on a communicat ...

, it allows users to run multiple programs concurrently in multiple

windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

Desq

Quarterdeck's predecessor to DESQview was a task switching product called Desq (shipped late April or May 1984) which allows users to switch between running programs. Quarterdeck revamped its package, bringing multitasking in, and adding TopView compatibility. DESQview was released in July 1985, four months before

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...

released the first version of

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

. 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 TopView TopView is the first object-oriented, multitasking, and windowing, personal computer operating environment for PC DOS developed by IBM, announced in August 1984 and shipped in March 1985. TopView provided a text-mode (although it also ran in gr ...

, which shipped March 1985, from which DESQview inherited the pop-up menu. Under DESQview, well-behaved DOS programs can be run concurrently in resizable, overlapping windows (something the first version of MS Windows cannot do). A simple hideable menu allows cutting and pasting between programs. DESQview provides support for simple editable macros as well. Quarterdeck also developed a set of optional utilities for DESQview, including a notepad and dialer. Later versions allow graphics mode programs to be loaded as well, but only run in full screen mode. DESQview is not a

GUI The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...

(Graphical User Interface)

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

. Rather, it is a non-graphical, windowed shell that runs in real mode on top of DOS, although it can run on any

Intel 8086 The 8086 (also called iAPX 86) is a 16-bit microprocessor chip designed by Intel between early 1976 and June 8, 1978, when it was released. The Intel 8088, released July 1, 1979, is a slightly modified chip with an external 8-bit data bus (allowi ...

- or

Intel 80286 The Intel 80286 (also marketed as the iAPX 286 and often called Intel 286) is a 16-bit microprocessor that was introduced on February 1, 1982. It was the first 8086-based CPU with separate, non- multiplexed address and data buses and also the ...

-based PC. It can also use

expanded memory In DOS memory management, expanded memory is a system of bank switching that provided additional memory to DOS programs beyond the limit of conventional memory (640 KiB). ''Expanded memory'' is an umbrella term for several incompatible tec ...

add-ons to work around the 640 kB

RAM limit Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch * Ra ...

conventional memory In DOS memory management, conventional memory, also called base memory, is the first 640 kilobytes of the memory on IBM PC or compatible systems. It is the read-write memory directly addressable by the processor for use by the operating system ...

on early PCs. DESQview really came into its own on

Intel 80386 The Intel 386, originally released as 80386 and later renamed i386, is a 32-bit microprocessor introduced in 1985. The first versions had 275,000 transistorsprotected mode, meaning that a misbehaving program can still crash the system.

DESQview and QEMM

To make maximum use of

extended memory In DOS memory management, extended memory refers to memory above the first megabyte (220 bytes) 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. D ...

Intel 80386 The Intel 386, originally released as 80386 and later renamed i386, is a 32-bit microprocessor introduced in 1985. The first versions had 275,000 transistors expanded memory In DOS memory management, expanded memory is a system of bank switching that provided additional memory to DOS programs beyond the limit of conventional memory (640 KiB). ''Expanded memory'' is an umbrella term for several incompatible tec ...

and upper memory blocks ( UMBs) accessible to DESQview and other real-mode programs, Quarterdeck developed a sophisticated memory manager. Owing to the foresight of its marketing manager, Quarterdeck marketed it as a separate product,

QEMM-386 Quarterdeck Expanded Memory Manager (QEMM) is a memory manager produced by Quarterdeck Office Systems in the late 1980s through the late 1990s. It was the most popular third-party memory manager for the MS-DOS and other DOS operating systems. ...

(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 Pentium is a brand used for a series of x86 architecture-compatible microprocessors produced by Intel. The original Pentium processor from which the brand took its name was first released on March 22, 1993. After that, the Pentium II and P ...

processor, the ''386'' in QEMM was dropped. The combination package of DESQview and QEMM-386 was called DESQview 386 (DV386). With the introduction of the 80386, the memory management features were enhanced to allow the system to shift into protected mode but also allow the addresses to be configured in a

virtual 8086 mode In the 80386 microprocessor and later, virtual 8086 mode (also called virtual real mode, V86-mode, or VM86) allows the execution of real mode applications that are incapable of running directly in protected mode while the processor is running a ...

so that the extended memory can be mapped into addressing frames and accessible to real-mode programs such as DOS. This allows a 386 to implement the LIM ( Lotus,

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...

) EMS (expanded memory specification). The memory manager is easily controlled by the user with DOS program QEMM.COM. DESQview is 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 can execute transparently during its context. The main copy of DOS and any device and networking drivers have to be loaded before DESQview. The resulting space is the largest single program that can run, but DESQview under QEMM can run as many instances of those programs as the EMS allows. So an 8 MB system can generally have a dozen full-sized DOS programs running concurrently; a 16 MB system can 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 has a clever interface that is 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, monitors the Alt key for isolated presses (not in combination). Pressing the Alt key by itself brings 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 causes DESQview to learn a set of keys as a macro. This allows 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. In one area, however, DESQview was a lasting success: many multiuser

bulletin board system A bulletin board system (BBS), also called computer bulletin board service (CBBS), is a computer server running software that allows users to connect to the system using a terminal program. Once logged in, the user can perform functions such as ...

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 In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex). Node may refer to: In mathematics * Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two or more curves, lines ...

, 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 allows 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 does not provide a graphical user interface (

). 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 MS Windows 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, Inc. (DR or DRI) was a company created by Gary Kildall to market and develop his CP/M operating system and related 8-bit, 16-bit and 32-bit systems like MP/M, Concurrent DOS, FlexOS, Multiuser DOS, DOS Plus, DR DOS and ...

's DR DOS 5.0, released in 1990. To catch on, Microsoft included its own

EMM386 EMM386 is the expanded memory manager of Microsoft's MS-DOS, IBM's PC DOS, Digital Research's DR-DOS, and Datalight's ROM-DOS which is used to create expanded memory using extended memory on Intel 80386 CPUs. There also is an EMM386.EXE availa ...

MS-DOS 5.0 MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few ope ...

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

Windows 3.1x Windows 3.1 is a major release of Microsoft Windows. It was released to manufacturing on April 6, 1992, as a successor to Windows 3.0. Like its predecessors, the Windows 3.1 series ran as a shell on top of MS-DOS. Codenamed Janus, Windows 3 ...

, but only for incremental benefit. 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 are

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(for Windows) and OS/2SPEED (for OS/2).

DESQview/X

Quarterdeck eventually also released a product named DESQview/X (DVX), which is an

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting wit ...

server running under DOS and DESQview and thus provides a GUI to which X software (mostly

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

) could be ported. DESQview/X had three window managers that it launched with, X/Motif,

OPEN LOOK OPEN LOOK (sometimes referred to as Open Look) is a graphical user interface (GUI) specification for UNIX workstations. It was originally defined in the late 1980s by Sun Microsystems and AT&T Corporation. History OPEN LOOK was created at a ...

, and

twm twm (Tab Window Manager) is a X window manager, window manager for the X Window System. Started in 1987 by Tom LaStrange, it has been the standard window manager for the X Window System since version X11R4. The name originally stood for Tom's Wi ...

. The default package contained only ''twm'', the others were costly optional extras, as was the ability to interact on

TCP/IP The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...

networks.

Mosaic A mosaic is a pattern or image made of small regular or irregular pieces of colored stone, glass or ceramic, held in place by plaster/mortar, and covering a surface. Mosaics are often used as floor and wall decoration, and were particularly pop ...

was ported to DVX. DVX itself can serve DOS programs and the 16-bit Windows environment across the network as X programs, which made it useful for those who wished to run DOS and Windows programs from their Unix workstations. The same functionality is available with some versions of NCD Wincenter.

NetWare Access Server

Internetworking company

Novell Novell, Inc. was an American software and services company headquartered in Provo, Utah, that existed from 1980 until 2014. Its most significant product was the multi-platform network operating system known as Novell NetWare. Under the lead ...

developed a product called NetWare Access Server (NAS) incorporating features of DESQview 386 and

pcAnywhere pcAnywhere is a discontinued 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 interconnected networks ...

. The DESQview multitasking support was used to create an environment into which up to 16 PC and Macintosh clients can 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 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. The second operating system in the 9x line, it is the successor to Windows 95, and was released to ...

was released. In the mid-1990s, Quarterdeck tried to recast itself as an

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...

company, releasing a version of the Mosaic web browser. Eventually, the company was acquired by Symantec.

Reception

BYTE The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

'' in 1984 stated that DesQ's application compatibility was the highest of the five window managers tested. The magazine in 1989 listed version 3.0 as among the "Distinction" winners of the BYTE Awards, stating that "unlike OS/2, DESQview lets you run the programs you've already paid for … Many users will find that DESQview is all they need".

References

External links

Screenshots of DESQview/X
* ({{cite web , url=http://sourceforge.net/projects/opendvx/ , title=Project: OpenDV/X: Summary , access-date=2016-06-25 , url-status=dead , archive-url=https://web.archive.org/web/20050518155818/http://sourceforge.net/projects/opendvx/ , archive-date=2005-05-18) DOS software Operating system APIs Process (computing)