TopView
Encyclopedia
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. Many industry leaders and insiders speculated on what was happening in the confidential confines of IBM Boca Raton. IBM demonstrated an early version of the product to key customers before making it generally available, around the time they shipped their new PC/AT
computer.
environment. TopView allowed IBM to sweeten the deal with customers, who were surprised that the new IBM AT did not come with an operating system
able to use the hardware multitasking and protected-mode features of the new 80286 CPU
, as DOS and most applications were still running in 8086/8088 real mode
.
Even given TopView's virtual memory management capabilities, hardware limitations still held the new environment back—a base AT with 256 KB of RAM only had room for 80 KB of application code and data in RAM once DOS and TopView had loaded up. 512-640 KB was recommended to load up two typical application programs of the time. This was the maximum the earlier IBM XT could have installed. Once loaded, TopView took back much of the memory consumed by DOS, but still not enough to satisify industry critics. TopView ran in real mode on any x86
processor and could run well behaved DOS programs (i.e. programs that did not write directly to the screen but used BIOS int 10h and DOS int 21h (such as the IBM Assistant Series of productivity programs)) in an arrangement of windows. Well behaved applications would use standard DOS and BIOS function calls to access system services and hardware. Misbehaving programs (i.e. such as programs that did write directly to the screen) such as Lotus 1-2-3, WordStar and dBase III would still run in the TopView environment, however, they would consume the entire screen. Object oriented applications were written using the TopView API. TopView was not updated to make use of the virtual 8086 mode
added in the Intel 80386
processors that allowed better virtualization.
Initially, compatibility with the extended features was limited mainly to IBM applications, along with a few third-party products like WordPerfect
and VolksWriter
. A chicken-and-egg situation developed where third-party developers were reluctant to add extended feature support (such as block insert and delete to allow users to do cut/copy/paste between applications) when they did not see market demand for them. Most DOS programs did, however, support these functions and did allow the user to perform the cut, copy, and paste operations by using the TopView pop-up menus.
Some believed that IBM planned to use TopView to force them to rely on them to comply with the new technical specifications. As later versions of TopView were released, it was able to successfully make more challenging DOS apps run in a multitasking fashion by intercepting direct access to system services and hardware.
TopView first introduced Program Information File
s (PIF files), which defined how a given DOS program should be run in a multi-tasking environment, notably to avoid giving it unnecessary resources which could remain available to other programs. TopView's PIF files were inherited and extended by Quarterdeck
's DESQview
and Microsoft Windows
. The concept of Program Information Files was also used under Digital Research
operating systems such as Concurrent DOS, Multiuser DOS
, System Manager and REAL/32, however, using the PIFED command, the necessary program information got directly embedded into the .EXE or .COM executable file.
programs was added—onto the hard disk on all computers and into the high memory area on machines equipped with a 286 CPU. The initially poor support for DOS batch files was improved.
Version 1.12, introduced in April 1987, added support for the new IBM PS/2 series
, their DOS 3.30
operating system, and their new PS/2 mice. It could also now use up to four serial ports.
task switchers like Ready, Spotlight, and Borland
's SideKick
who didn't need a multitasking environment. TopView ran in graphics mode (TOPVIEW /G), however, this was rarely used. By mid-1987, IBM began to shift focus away from TopView and was promoting the use of OS/2
to developers and end users alike. OS/2 1.0 was a pre-emptive multitasking, multithreading OS that allowed one real mode and multiple 16-bit protected mode sessions to run at the same time on the PC/AT based 80286 and provided as a DOS alternative announced in April 1987 and made available later that December. A graphical user interface (Presentation Manager
) was added with OS/2 1.1 in October 1988. 1.1 could run with or without Presentation Manager as well as an embedded system
with no screen, keyboard or mouse interface required. IBM officially stopped marketing the final release of TopView, version 1.12, on 3 July 1990. TopView's concept was carried forward by other DOS multitaskers, most notably Quarterdeck's DESQview
, which retained TopView's user interface and many features, plus added more features such as support for the special features of the 80286, 80386 and compatible processors, and, with DESQview/X (released in June 1992), a true GUI interface running on DOS. A variety of similar programs to TopView were also available, including one from Dynamical Systems called Mondrian, which Microsoft bought in 1986 with the stated intention of implementing TopView API compatibility into Windows which never happened. Later in April 1992, IBM introduced OS/2 2.0 which included virtual 8086 mode
and full 32-bit support of the Intel 80386 superseding even DESQview and other similar environments. OS/2 2.0 was a priority based preemptive multitasking multithreading OS including 32 levels of priority (from time critical to idle time) for the 386.
TopView requires IBM PC DOS versions 2.0 to 5.0 or MS-DOS 2.0 to 6.0, and will not run with later releases.
Key contributors to TopView included David Morrill (the "father of TopView" code-named "Orion" once the GLASS project was moved to Boca Raton), Dennis McKinley (tasking), Ross Cook (memory management), Bob Hobbs (TopView Toolkit) and Neal Whitten (product manager). Bill Gates, Steve Ballmer, Gordon Letwin and other key Microsoft executives accepted an invitation to IBM Boca Raton to see a special demonstration of TopView. Gates was disturbed that Windows did not have the tasking and windowing capabilities (i.e. overlapping windows, etc.) that TopView had. Gates witnessed TopView running multiple copies of the Microsoft BASIC interpreter running in windows (overlapping and side-by-side) in a multitasking fashion. This lead to the eventual Microsoft purchase of Mondrian, a Windows requirement to do overlapping windows (as later introduced with Windows 2.0) and later the development of Windows NT (to do adequate multitasking) and its eventual release in July of 1993. Much of the design requirements for Windows NT came out of the original joint development agreement that IBM had with Microsoft for the development of OS/2. Microsoft did not, however, have a JDA with IBM for the development of TopView.
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...
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. Many industry leaders and insiders speculated on what was happening in the confidential confines of IBM Boca Raton. IBM demonstrated an early version of the product to key customers before making it generally available, around the time they shipped their new PC/AT
IBM Personal Computer/AT
The IBM Personal Computer AT, more commonly known as the IBM AT and also sometimes called the PC AT or PC/AT, was IBM's second-generation PC, designed around the 6 MHz Intel 80286 microprocessor and released in 1984 as machine type 5170...
computer.
Hopeful beginnings
IBM determined that the microcomputer market needed a multitaskingComputer 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...
environment. TopView allowed IBM to sweeten the deal with customers, who were surprised that the new IBM AT did not come with an 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...
able to use the hardware multitasking and protected-mode features of the new 80286 CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
, as DOS and most applications were still running in 8086/8088 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...
.
Even given TopView's virtual memory management capabilities, hardware limitations still held the new environment back—a base AT with 256 KB of RAM only had room for 80 KB of application code and data in RAM once DOS and TopView had loaded up. 512-640 KB was recommended to load up two typical application programs of the time. This was the maximum the earlier IBM XT could have installed. Once loaded, TopView took back much of the memory consumed by DOS, but still not enough to satisify industry critics. TopView ran in real mode on any x86
X86 architecture
The term x86 refers to a family of instruction set architectures based on the Intel 8086 CPU. The 8086 was launched in 1978 as a fully 16-bit extension of Intel's 8-bit based 8080 microprocessor and also introduced segmentation to overcome the 16-bit addressing barrier of such designs...
processor and could run well behaved DOS programs (i.e. programs that did not write directly to the screen but used BIOS int 10h and DOS int 21h (such as the IBM Assistant Series of productivity programs)) in an arrangement of windows. Well behaved applications would use standard DOS and BIOS function calls to access system services and hardware. Misbehaving programs (i.e. such as programs that did write directly to the screen) such as Lotus 1-2-3, WordStar and dBase III would still run in the TopView environment, however, they would consume the entire screen. Object oriented applications were written using the TopView API. TopView was not updated to make use of the 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...
added in the 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 that allowed better virtualization.
Initially, compatibility with the extended features was limited mainly to IBM applications, along with a few third-party products like WordPerfect
WordPerfect
WordPerfect is a word processing application, now owned by Corel.Bruce Bastian, a Brigham Young University graduate student, and BYU computer science professor Dr. Alan Ashton joined forces to design a word processing system for the city of Orem's Data General Corp. minicomputer system in 1979...
and VolksWriter
VolksWriter
Volkswriter was a 1980s-era word processor created and distributed by Lifetree Software, Inc.Volkswriter was first published in 1982, and was the first word processor for the IBM PC Lifetree published versions of the software until May, 1989 when due to profitability problems, the Volkswriter...
. A chicken-and-egg situation developed where third-party developers were reluctant to add extended feature support (such as block insert and delete to allow users to do cut/copy/paste between applications) when they did not see market demand for them. Most DOS programs did, however, support these functions and did allow the user to perform the cut, copy, and paste operations by using the TopView pop-up menus.
Some believed that IBM planned to use TopView to force them to rely on them to comply with the new technical specifications. As later versions of TopView were released, it was able to successfully make more challenging DOS apps run in a multitasking fashion by intercepting direct access to system services and hardware.
TopView first introduced Program Information File
Program Information File
A PIF, or Program Information File, defines how a given DOS program should be run in a multi-tasking environment, notably to avoid giving it unnecessary resources which could remain available to other programs. TopView was the originator of PIFs which were inherited and extended by DESQview and...
s (PIF files), which defined how a given DOS program should be run in a multi-tasking environment, notably to avoid giving it unnecessary resources which could remain available to other programs. TopView's PIF files were inherited and extended by Quarterdeck
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...
's DESQview
DESQview
DESQview was a text mode multitasking program developed by Quarterdeck Office Systems which enjoyed modest popularity in the late 1980s and early 1990s...
and 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...
. The concept of Program Information Files was also used under 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...
operating systems such as Concurrent DOS, Multiuser DOS
Multiuser DOS
Multiuser DOS is a soft real-time multi-user multi-tasking operating system for IBM PC-compatible microcomputers.An evolution of the older Concurrent CP/M-86 and Concurrent DOS operating systems, it was originally developed by Digital Research and later further developed by Novell...
, System Manager and REAL/32, however, using the PIFED command, the necessary program information got directly embedded into the .EXE or .COM executable file.
Version history
Version 1.1, introduced in June 1986, added support for the IBM PC Local Area Network Program and IBM's 3270 terminal emulator. Importantly, support for swapping non-residentTerminate and Stay Resident
Terminate and Stay Resident is a computer system call in DOS computer operating systems that returns control to the system as if the program has quit, but keeps the program in memory...
programs was added—onto the hard disk on all computers and into the high memory area on machines equipped with a 286 CPU. The initially poor support for DOS batch files was improved.
Version 1.12, introduced in April 1987, added support for the new IBM PS/2 series
IBM Personal System/2
The Personal System/2 or PS/2 was IBM's third generation of personal computers. The PS/2 line, released to the public in 1987, was created by IBM in an attempt to recapture control of the PC market by introducing an advanced proprietary architecture...
, their DOS 3.30
Timeline of x86 DOS operating systems
This article presents a timeline of events in the history of x86 DOS operating systems from 1973 to 2006.-Important Events in DOS History:-See also:*Comparison of x86 DOS operating systems*Timeline of Microsoft Windows*Timeline of OpenBSD...
operating system, and their new PS/2 mice. It could also now use up to four serial ports.
Decline and discontinuation
TopView sold below expectations from the start, with many potential users already satisfied with cheaper, less memory-intensive TSRTerminate and Stay Resident
Terminate and Stay Resident is a computer system call in DOS computer operating systems that returns control to the system as if the program has quit, but keeps the program in memory...
task switchers like Ready, Spotlight, and Borland
Borland
Borland Software Corporation is a software company first headquartered in Scotts Valley, California, Cupertino, California and finally Austin, Texas. It is now a Micro Focus subsidiary. It was founded in 1983 by Niels Jensen, Ole Henriksen, Mogens Glad and Philippe Kahn.-The 1980s:...
's SideKick
SideKick
SideKick was an early Personal Information Manager software application by Borland launched in 1983 under Philippe Kahn's leadership. It was notable for being a Terminate and Stay Resident program, which enabled it to load into memory then return the computer to the DOS command prompt, allowing...
who didn't need a multitasking environment. TopView ran in graphics mode (TOPVIEW /G), however, this was rarely used. By mid-1987, IBM began to shift focus away from TopView and was promoting the use of OS/2
OS/2
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "Personal System/2 " line of second-generation personal...
to developers and end users alike. OS/2 1.0 was a pre-emptive multitasking, multithreading OS that allowed one real mode and multiple 16-bit protected mode sessions to run at the same time on the PC/AT based 80286 and provided as a DOS alternative announced in April 1987 and made available later that December. A graphical user interface (Presentation Manager
Presentation Manager
Presentation Manager is the graphical user interface that IBM and Microsoft introduced in version 1.1 of their operating system OS/2 in late 1988.-History:...
) was added with OS/2 1.1 in October 1988. 1.1 could run with or without Presentation Manager as well as an embedded system
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
with no screen, keyboard or mouse interface required. IBM officially stopped marketing the final release of TopView, version 1.12, on 3 July 1990. TopView's concept was carried forward by other DOS multitaskers, most notably Quarterdeck's DESQview
DESQview
DESQview was a text mode multitasking program developed by Quarterdeck Office Systems which enjoyed modest popularity in the late 1980s and early 1990s...
, which retained TopView's user interface and many features, plus added more features such as support for the special features of the 80286, 80386 and compatible processors, and, with DESQview/X (released in June 1992), a true GUI interface running on DOS. A variety of similar programs to TopView were also available, including one from Dynamical Systems called Mondrian, which Microsoft bought in 1986 with the stated intention of implementing TopView API compatibility into Windows which never happened. Later in April 1992, IBM introduced OS/2 2.0 which included 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...
and full 32-bit support of the Intel 80386 superseding even DESQview and other similar environments. OS/2 2.0 was a priority based preemptive multitasking multithreading OS including 32 levels of priority (from time critical to idle time) for the 386.
TopView requires IBM PC DOS versions 2.0 to 5.0 or MS-DOS 2.0 to 6.0, and will not run with later releases.
Key contributors to TopView included David Morrill (the "father of TopView" code-named "Orion" once the GLASS project was moved to Boca Raton), Dennis McKinley (tasking), Ross Cook (memory management), Bob Hobbs (TopView Toolkit) and Neal Whitten (product manager). Bill Gates, Steve Ballmer, Gordon Letwin and other key Microsoft executives accepted an invitation to IBM Boca Raton to see a special demonstration of TopView. Gates was disturbed that Windows did not have the tasking and windowing capabilities (i.e. overlapping windows, etc.) that TopView had. Gates witnessed TopView running multiple copies of the Microsoft BASIC interpreter running in windows (overlapping and side-by-side) in a multitasking fashion. This lead to the eventual Microsoft purchase of Mondrian, a Windows requirement to do overlapping windows (as later introduced with Windows 2.0) and later the development of Windows NT (to do adequate multitasking) and its eventual release in July of 1993. Much of the design requirements for Windows NT came out of the original joint development agreement that IBM had with Microsoft for the development of OS/2. Microsoft did not, however, have a JDA with IBM for the development of TopView.
External links
- TopView: An early multi-tasking OS for the PC A history of TopView by its lead developer