Editing IBM TopView

{{short description|Former front-end to DOS}}
{{Infobox OS
| name = TopView
| logo = IBM TopView Logo.svg
| screenshot = Topviewvirtualpc.jpg
| caption = A typical TopView session
| developer = [[IBM]]
| source_model = [[Closed source]]
| supported_platforms = [[x86]], ([[DOS]] 2.0 – 6.0)
| working_state = Discontinued
| released = {{Start date and age|1985|03}}<ref name=ibmtopviewann1984>{{cite web |publisher=IBM |type=Announcement letter |date=1984-08-14 |title=IBM Personal Computer Programming Enhanced With TopView |url=https://www.ibm.com/docs/en/announcements/archive/ENUS284-282}}</ref><ref name=ibmtopview1985>{{cite web |publisher=IBM |type=Announcement letter |date=1985-02-19 |title=TopView and TopView Programmer's Toolkit Available For Shipment Week Of March 8, 1985 Enhanced Warranty Provisions |url=https://www.ibm.com/docs/en/announcements/archive/ENUS285-071}}</ref><ref name="dvorak">{{cite news |url=https://www.dvorak.org/blog/whatever-happened-to-ibms-topview/ |author-first=John C. |author-last=Dvorak |title=Whatever Happened to Topview? |date=2007-01-16}}</ref>
| latest_release_version = 1.12
| latest_release_date = {{Start date and age|1987|04|02}}
| marketing_target = Business
| ui = [[Text-based user interface|Text-based]] ([[text mode]])
| license = [[Proprietary software|Proprietary]]
}}

'''TopView''' is the first [[object-oriented]], [[Computer multitasking|multitasking]], and windowing, [[personal computer]] [[operating environment]] for [[IBM PC DOS|PC DOS]] developed by [[IBM]], announced in August 1984<ref name="ibmtopviewann1984"/> and shipped in March 1985.<ref name="ibmtopview1985"/><ref name="dvorak"/> TopView provided a [[text-mode]] (although it also ran in graphics mode) [[operating environment]] that allowed users to run more than one application at the same time on a [[IBM PC compatible|PC]]. IBM demonstrated an early version of the product to key customers before making it generally available, around the time they shipped their new [[IBM Personal Computer AT|PC AT]] computer.

== History ==
When [[Microsoft]] announced [[Windows 1.0]] in November 1983, [[International Business Machines]] (IBM), Microsoft's important partner in popularizing MS-DOS for the [[IBM Personal Computer|IBM PC]], notably did not announce support for the forthcoming window environment.<ref name="MS Windows 1983">{{cite magazine |author-last=Markoff |author-first=John |title=Microsoft Does Windows |magazine=[[InfoWorld]] |volume=5 |issue=47 |pages=32–36 |publisher=[[CW Communications|Popular Computing, Inc.]] |location=Menlo Park, CA |date=1983-11-21 |url=https://books.google.com/books?id=uy8EAAAAMBAJ&pg=PA32 |issn=0199-6649}}</ref> IBM determined that the microcomputer market needed a [[computer multitasking|multitasking]] environment. When it released TopView in 1985, the press speculated that the software was the start of IBM's plan to increase its control over the IBM PC (even though IBM published the specifications publicly) by creating a proprietary operating system for it, similar to what IBM had offered for years on its larger computers.<ref name="edelhart19850430">{{cite magazine |url=https://books.google.com/books?id=vVNXxWE6BX0C&pg=PA125 |title=TopView Enters the Fray |magazine=[[PC Magazine]] |date=1985-04-30 |access-date=2013-10-28 |author-last=Edelhart |author-first=Mike |pages=125–126}}</ref> TopView also allowed IBM to serve 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]] [[central processing unit|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&mdash;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 Personal Computer XT|IBM XT]] could have installed. Once loaded, TopView took back much of the memory consumed by DOS, but still not enough to satisfy industry critics. TopView ran in real mode on any [[x86 architecture|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.<ref name="prom">{{cite news |title=IBM TopView Promising but Has Limitations |date=1985-06-17 |author-first=Lawrence J. |author-last=Magid |url=https://www.latimes.com/archives/la-xpm-1985-06-17-fi-12704-story.html |work=[[Los Angeles Times]]}}</ref> 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, but would consume the entire screen.<ref name="IBM_1986_Announcement"/>  [[Object-oriented]] applications were written using the TopView API. TopView was developed to run on the 8088 (and required what IBM referred to as a fixed disk) and later the 80286. TopView was not updated to make use of the [[virtual 8086 mode]] added in the [[Intel 80386]] processors that allowed better [[Hardware-assisted virtualization|virtualization]].{{Citation needed|date=May 2011}}

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.<ref name="prom"/> 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 reliance on them to comply with the new technical specifications.<ref name="dvorak"/>  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 Office Systems|Quarterdeck]]'s [[DESQview]] and [[Microsoft Windows]].<ref>{{cite journal |url=https://drdobbs.com/architecture-and-design/undocumented-corner/184409042 |magazine=[[Dr. Dobb's Journal]] |department=Undocumented Corner |title=The PIF File Format, or, TopView (sort of) Lives! |date=July 1, 1993}}</ref> The concept of Program Information Files was also used under [[Digital Research]] operating systems such as [[Concurrent DOS]]<!-- at least in Concurrent DOS XM and Concurrent DOS 386 since 1987 -->, [[Multiuser DOS]], [[Datapac System Manager]] and [[REAL/32]]; however, using the PIFED command, the necessary program information got directly embedded into the .EXE or .COM executable file.<ref>{{cite book |publisher=[[Digital Research]] |title=Concurrent DOS 386 - Multiuser/Multitasking Operating System - Reference Manual'' |date=1987 |url=http://bitsavers.trailing-edge.com/pdf/digitalResearch/concurrent/1126-2064-001_Concurrent_DOS_386_Reference_Guide_Nov87.pdf}}</ref>

== Version history ==
Version 1.1, introduced in June 1986, added support for the [[IBM PC Network]] and [[IBM 3270]] [[terminal emulation]]. Importantly, support for swapping non-[[Terminate-and-stay-resident program|resident]] programs was added&mdash;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.<ref name="IBM_1986_Announcement">{{cite web |publisher=IBM |type=Announcement letter |date=1986-06-25 |title=TopView Version 1.1 |url=https://www.ibm.com/docs/en/announcements/archive/ENUSZP86-4028}}</ref><!--This seems to indicate 1.11 may have been skipped over for TopView, because the PC LAN software needed a bug-fix release and the two programs had their version numbers synchronized{{cite |work=[[InfoWorld]] |date=1986-06-23 |author-first1=Karen |author-last1=Sorensen |author-first2=Laurie |author-last2=Flynn |title=IBM's Revision of PC LAN Released Without Fanfare |url=https://books.google.com/books?id=TC8EAAAAMBAJ&pg=PA5}} -->

Version 1.12, introduced in April 1987, added support for the new [[IBM Personal System/2|IBM PS/2 series]], their [[Timeline of DOS operating systems|DOS 3.30]] operating system, and their new PS/2 mice. It could also now use up to four serial ports.<ref name="IBM_1987_Announcement">{{cite web |publisher=IBM |type=Announcement letter |date=1987-04-02 |title=TopView Version 1.2 |url=https://www.ibm.com/docs/en/announcements/archive/ENUSZP87-4067}}</ref>

== Decline and discontinuation ==
TopView sold below expectations from the start, with many potential users already satisfied with cheaper, less memory-intensive [[terminate-and-stay-resident]] task switchers like Ready, Spotlight, and [[Borland Sidekick]] which didn't need a multitasking environment.<ref>{{citation |title=Speculation About Topview Persists |author-first=Steven |author-last=Burke |work=[[InfoWorld]] |date=1985-10-07 |pages=34–35 |url=https://books.google.com/books?id=jC8EAAAAMBAJ&pg=PA34}}</ref> 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.<ref name="dvorak"/> 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 [[Nathan Myhrvold#Early career|Dynamical Systems called Mondrian]], which Microsoft bought in 1986 with the stated intention of implementing TopView API compatibility into Windows which never happened.<ref>{{citation |work=[[InfoWorld]] |date=1986-06-30 |title=Software Makers Lean To Microsoft's Windows |author-first=Tom |author-last=Moran |page=5 |url=https://books.google.com/books?id=Wi8EAAAAMBAJ&pg=RA1-PA5}}</ref> 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 from IBM executive [[Don Estridge]] to IBM Boca Raton to see a special demonstration of TopView. Gates was disturbed that Windows did not have the [[Computer multitasking|multitasking]] (Windows used a [[Cooperative multitasking|cooperative]] method to share the CPU) 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 [[Computer multitasking|multitasking]] fashion. Microsoft later released a multitasking version of [[MS-DOS 4.0 (multitasking)]] from what it learned from the meeting. Even though there was no joint development agreement with Microsoft for the development of TopView, Estridge asked and later told Whitten (against Whitten's and the TopView team's wishes) to turn over all source code and documentation of TopView to Microsoft. Within a short time after the meeting, Estridge's request was granted. Gates gave the code and documentation to a group headed by [[Nathan Myhrvold]]. Once the code had been modified according to Gates' specifications, he purchased the company. The product itself, Mondrian, was never released.  Gates, however, gave members of the team key positions at Microsoft. This led to a Joint Development Agreement with Microsoft (an agreement that previously only included [[DOS]]) to co-develop [[OS/2]] (an agreement that lasted until 1990). This was all done in order to satisfy the USA vs. IBM anti-trust court case that was filed in 1969. Even though it was dismissed in 1982, IBM was mired in antitrust troubles for more than a decade after the dismissal and did not recover from the legal morass until the early to mid-90s. In June 1990 an FTC probe was launched into possible collusion between Microsoft and IBM in the PC software market.

==Reception==
''InfoWorld'' in 1985 described TopView as "bland, plain vanilla software that hogs far too much memory".<ref name="fawcette19850311">{{cite magazine |url=https://books.google.com/books?id=5C4EAAAAMBAJ&pg=PA5 |title=Awaiting PC AT Clones |magazine=[[InfoWorld]] |date=1985-03-11 |access-date=2015-02-01 |author-last=Fawcette |author-first=James E. |page=5 |type=editorial}}</ref> ''[[BYTE]]'' also criticized TopView's memory usage, but stated that "you will find that most software written for the IBM PC is TopView-compatible". Noting the low price and "innovative multitasking features", the magazine predicted that the software "will attract a lot of takers".<ref name="byers1985fall">{{cite journal |url=https://archive.org/stream/byte-magazine-1985-11/1985_11_BYTE_10-11_Inside_the_IBM_PCs#page/n249/mode/2up |title=TopView |journal=[[BYTE]] |date=Fall 1985 |access-date=2016-03-19 |author-last=Byers |author-first=T. J. |page=247}}</ref>

In 1985, [[Digital Research]] positioned their multitasking [[Concurrent DOS 4.1]] with [[Graphics Environment Manager|GEM]] as alternative for TopView.<ref>{{cite journal |author=CW |title=Concurrent DOS 4.1 in den USA angekündigt |language=de |date=1985-06-21 |journal=[[Computerwoche]] |url=http://www.computerwoche.de/a/concurrent-dos-4-1-in-den-usa-angekuendigt,1169757 |access-date=2017-01-18 |url-status=live |archive-url=https://web.archive.org/web/20170118112800/http://www.computerwoche.de/a/concurrent-dos-4-1-in-den-usa-angekuendigt%2C1169757 |archive-date=2017-01-18 }}</ref>

== See also ==
* [[DOS Shell]]
* [[MS-DOS 4.0 (multitasking)]]
* [[OS/2]]
* [[Visi On]]
* [[VM/386]]

== References ==
{{Reflist}}

== External links ==
* [https://web.archive.org/web/20100323051442/http://www.dmorrill.com/david/projects/topview/intro.php TopView: An early multi-tasking OS for the PC] - a history of TopView by its lead developer

{{IBM}}

{{DEFAULTSORT:Ibm Topview}}
[[Category:DOS software]]
[[Category:IBM software|TopView]]
[[Category:Operating system APIs]]
[[Category:Process (computing)]]