NetWare Access Server
| Industry | Software |
|---|---|
| Founded | 1980s |
| Products | DESQview, QEMM-386, DESQview/X |
DESQview (abbreviated as DV) is a text mode multitasking operating environment created by Quarterdeck Office Systems that achieved moderate recognition during the late 1980s and early 1990s. Operating atop DOS, it allows multiple applications to run simultaneously within separate windowed environments.
Desq
Before DESQview, Quarterdeck introduced Desq, a task-switching utility launched in spring 1984, which enabled users to alternate between active programs. DESQview debuted in July 1985, preceding Microsoft's initial Windows release by four months, bringing true multitasking capabilities and compatibility with IBM's TopView (released March 1985).
DESQview facilitates the concurrent operation of well-behaved DOS applications within resizable and overlapping windows—functionality that early Windows versions lacked. It features a menu that can be hidden, allowing users to perform cut-and-paste operations across programs, and supports simple editable macros. Quarterdeck supplemented DESQview with optional tools such as a notepad and dialer. Later releases extended support to graphics mode applications, although only in full-screen mode.
Unlike graphical user interface (GUI) operating systems, DESQview functions as a non-graphical windowed shell running in real mode on top of DOS, compatible with Intel 8086 and 80286 processors. It utilizes expanded memory hardware to circumvent the 640 KB conventional memory limit but achieves optimal performance on Intel 80386 machines, which better exploit memory beyond DOS constraints. However, because it operates in real mode, system instability can occur if programs malfunction.
DESQview and QEMM
To maximize extended memory utilization on Intel 80386 CPUs, Quarterdeck developed QEMM-386 (Quarterdeck Expanded Memory Manager), an advanced DOS memory manager that converts extended memory into expanded memory and upper memory blocks accessible by DESQview and other real-mode applications. Sold separately, QEMM surpassed DESQview in sales volume, generating over US$150 million between 1987 and 1994. Following the introduction of the Intel Pentium processor, the "386" suffix was dropped. The combined offering was branded DESQview 386 (DV386).
QEMM improved memory management by enabling protected mode operation with virtual 8086 addressing, mapping extended memory for use by real-mode programs while supporting the LIM EMS (Lotus-Intel-Microsoft Expanded Memory Specification). Users configure QEMM through the DOS utility QEMM.COM.
DESQview takes advantage of QEMM beyond standard LIM EMS by remapping conventional memory below 640 KB into multiple extended memory segments for seamless execution during task switches. Loading DOS and device drivers prior to launching DESQview maximizes available memory. As a result, a system with 8 MB RAM can run approximately a dozen full-featured DOS applications simultaneously; a machine with 16 MB can support more than twenty concurrent programs.
DESQview usage
DESQview was compatible with all popular DOS applications, providing notable stability and performance within the limitations of DOS. Its interface was minimally intrusive, easily accessible, and user-friendly.
The software employed standard PC modifier keys—Control, Alt, and Shift—with the Alt key serving as a shortcut to open the DESQview menu when pressed alone. This menu allowed users to initiate new tasks, switch between running programs, select and paste text, adjust window size or position, and customize menu options. Pressing Shift+Alt enabled macro recording so that DESQview could automate launching other programs without interfering with their key assignments.
Despite receiving critical praise, DESQview did not achieve widespread mainstream adoption despite Quarterdeck’s promotional efforts. Nevertheless, it found enduring success within multiuser bulletin board systems (BBS), owing to its modest hardware requirements, robust multitasking capabilities, and superior management of multiple communication ports. While most BBS software operated as single-tasking DOS applications limited to one node per computer, DESQview—frequently paired with 16550 UART chips—allowed multiple instances of identical BBS software to run concurrently on a single machine, facilitating multi-user functionality.
Decline of DESQview
DESQview did not feature a graphical user interface (GUI). Although Quarterdeck provided programming libraries and tools to utilize its capabilities, these resources did not achieve broad acceptance. The combination of runtime licensing fees and the expense of development tools discouraged many commercial software developers.
The launch of Windows 3.0 by Microsoft brought built-in memory management and multitasking functionalities. Although DESQview offered superior speed, a smaller footprint, and greater stability, it was more expensive and lacked compatibility with Windows' graphical features.
QEMM's downturn started when Digital Research included a memory manager in DR DOS 5.0 (1990), followed by Microsoft integrating EMM386 into MS-DOS 5.0. While QEMM continued to provide incremental advantages with Windows 3.1x, its market demand declined. In August 1994, facing ongoing financial losses, Quarterdeck reduced its staff by 25%, and founder Terry Myers stepped down.
As users migrated from DESQview toward platforms such as Windows 3.x and OS/2, third-party utilities like TAME (for Windows) and OS/2SPEED replicated DESQview API functions to allow DOS applications to cooperate within these newer operating systems.
DESQview/X
Quarterdeck introduced DESQview/X (DVX), an X Window System server designed to run on DOS and DESQview, providing a graphical environment primarily for porting Unix software.
At launch, DVX supported three window managers: X/Motif, OPEN LOOK, and twm. The default installation included only twm, while the other managers and TCP/IP networking capabilities were offered as premium add-ons. The Mosaic browser was also ported to DVX.
DVX enabled DOS applications and the 16-bit Windows environment to operate over networks as X clients, allowing remote access from Unix workstations. Comparable features were available in certain NCD Wincenter editions.
NetWare Access Server
Novell created NetWare Access Server (NAS), which combined DESQview 386 multitasking features with pcAnywhere, permitting up to 16 PC and Macintosh clients to connect remotely, utilize NetWare resources, and run DOS programs simultaneously.
DESQview after X
Development of DESQview continued alongside DESQview/X, with a newer version of DESQview released following the discontinuation of DVX. QEMM also remained under active development beyond DESQview's lifecycle, including a variant compatible with Windows 98.
During the mid-1990s, Quarterdeck shifted focus toward the Internet sector by launching a version of the Mosaic web browser. Ultimately, the company was acquired by Symantec.
Reception
In 1984, BYTE commended DesQ for having the highest application compatibility among five window managers evaluated. By 1989, columnist Jerry Pournelle remarked that "while MultiFinder doesn't work very well yet, DESQView on a big 80386 machine certainly does," favoring it over OS/2 on 286 hardware. That same year, BYTE awarded version 3.0 a "Distinction," noting 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."