View source for GEOS (16-bit operating system)

{{Short description|Graphical operating system (16-bit)}}
{{Redirect|NewDeal|the economic program|New Deal}}
{{More citations needed|date=August 2009}}
{{Expand German|PC/GEOS|topic=tech|date=September 2018}}

{{Use dmy dates|date=May 2019|cs1-dates=y}}
{{Infobox OS
| name = PC/GEOS
| screenshot = BBENS412.png<!-- Do not change unless you have read "Wikipedia:Software_screenshots"! -->
| caption = A screenshot of Breadbox Ensemble 4.1.2
| developer = [[Berkeley Softworks]]
| programmed in = [[Assembly language|Assembly]], [[C (programming language)|C]]
| working state = Supported
| source model = [[Open source]], formerly [[closed source]]
| released = {{Start date and age|1990|df=yes}}
| latest release version = 4.1.3
| latest release date = {{Start date and age|2009|08|25|df=yes}}
| repo = {{URL|github.com/bluewaysw}}
| influenced by = [[GEOS (8-bit operating system)|GEOS (8-bit)]]
| ui = [[Motif (software)|Motif]] or "Win95 clone"
| license = [[Apache License|Apache]]
}}

'''GEOS''' (later renamed '''GeoWorks Ensemble''', '''NewDeal Office''', and '''Breadbox Ensemble''') is a computer [[operating environment]], [[graphical user interface]] (GUI), and suite of [[application software]]. Originally released as '''PC/GEOS''', it runs on [[MS-DOS]]-based, [[IBM PC compatible]] computers. Versions for some handheld platforms were also released and licensed to some companies.<ref>{{cite web |url=http://breadbox.com:80/geos.asp |title=Welcome to Breadbox |date=2004-12-04 |website=Breadbox Computer Company |url-status=dead |archive-url=https://web.archive.org/web/20041204065833/http://breadbox.com/geos.asp |archive-date=2004-12-04 |access-date=2018-01-24}}</ref>

PC/GEOS was first created by [[Berkeley Softworks]], which later became GeoWorks Corporation. Version 4.0 was developed in 2001 by Breadbox Computer Company, [[limited liability company]] (LLC), and was renamed Breadbox Ensemble. In 2015, Frank Fischer, the CEO of Breadbox, died and efforts on the [[operating system]] stopped until later in 2017 when it was bought by blueway.Softworks.<ref>{{cite web |url=http://geos-infobase.de/AKT2017.HTM#NEUJAHR |title=News 2017 |last1=Mützel |first1=Bernd |last2=Cordes |first2=Ulrich |date=1999–2018 |website=GEOS-InfoBase |language=de |access-date=2021-04-22 |archive-date=2018-08-27  |archive-url=https://web.archive.org/web/20180827110418/http://geos-infobase.de/AKT2017.HTM#NEUJAHR |url-status=dead }}</ref><ref>{{cite web |url=https://sites.google.com/site/geosresource/news/welcomehomegeos |title=Welcome home, GEOS Resource |website=sites.google.com |access-date=2018-01-24 }}{{Dead link|date=March 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

PC/GEOS should not be confused with the [[GEOS (8-bit operating system)|8-bit GEOS]] product from the same company, which runs on the [[Commodore 64]] and [[Apple II]].

== PC/GEOS ==
=== GeoWorks Ensemble ===
{{anchor|GOC|Espire}} In 1990, GeoWorks (formerly [[Berkeley Softworks]]) released PC/GEOS for [[IBM PC compatible]] systems.<ref>{{cite web |url=http://geos-infobase.de/GEOS1/GEO1.HTM |title=GeoWorks Ensemble 1 |website=GEOS-InfoBase |language=de |access-date=2021-04-22}}</ref> Commonly referred to as ''GeoWorks Ensemble'', it was incompatible with the earlier [[GEOS (8-bit operating system)|8-bit versions of GEOS]] for [[Commodore International|Commodore]] and [[Apple II]] computers, but provided numerous enhancements, including scalable fonts and multitasking on [[IBM Personal Computer XT|IBM PC XT]]- and [[IBM Personal Computer AT|AT]]-class PC clones. GeoWorks saw a market opportunity to provide a graphical user interface for the 16 million older model PCs that were unable to run Microsoft Windows 2.x.<ref name="Loli">{{cite web |url=http://www.osnews.com/story/1864 |title=Interview With Adam de Boor, ex-CTO of GeoWorks |last=Loli |first=Eugenia |date=2002-10-03 |website=OSnews |access-date=2019-04-30}}</ref>

GEOS was packaged with a suite of productivity applications. Each had a name prefixed by "Geo": GeoWrite, GeoDraw, GeoManager, GeoPlanner, GeoDex, and GeoComm. It was also bundled with many PCs at the time, but like other GUI environments for the PC platform, such as [[GEM (desktop environment)|Graphics Environment Manager]] (GEM), it ultimately proved less successful in the marketplace than Windows. Former CEO of GeoWorks claims that GEOS faded away "because Microsoft threatened to withdraw supply of [[MS-DOS]] to hardware manufacturers who bundled Geoworks with their machines".<ref>{{cite news |editor-last=Dougherty |editor-first=Brian |editor-link=Brian P. Dougherty |date=2010-07-24 |title=Comments by BrianDoc |url=https://www.economist.com/user/3755826/comments |quote=What killed us was that Microsoft realized what we had before the rest of the industry, they went to all of their OEMs and signed them to 2 year exclusive deals to put Windows on every machine. |access-date=2012-06-15}}</ref>

In December 1992, [[NEC]] and [[Sony]] bundled an [[original equipment manufacturer]] (OEM) version of GeoWorks named the CD Manager with their respective CD-ROM players that sold as retail box add-on peripherals for consumers.<ref>{{cite web |url=http://geos-infobase.de/ND_DOCS/228.HTM |title=228: CD-ROM Manager, Sony and NEC |website=GEOS-InfoBase |language=de |access-date=2021-04-22}}</ref> The NEC Bundle retailed for around $500.00 with a 1x external [[CD-ROM]], ''Small Computer System Interface'' ([[SCSI]]) interface controller, Labtec CD-150 amplified stereo speakers and 10 software titles.

A scaled-down version of GeoWorks was used by [[AOL|America Online]] for their MS-DOS-based AOL client software from the time of introduction on IBM compatible PCs until the late 1990s when America Online dropped development for graphical DOS in favor of Microsoft Windows. During that time, the popular single 3.5" [[self-booting disk]] that AOL was distributing could be hacked to [[Booting|boot]] the GeoWorks environment.{{cn|date=July 2022}}

IBM released the PC/GEOS-based [[EduQuest]] SchoolView network management tool for K-12 schools in 1994.<ref>{{Cite web |title=IBM Schoolview wiedergefunden? |language=de |url=http://s266590939.online.de/Infobase/WBB_317/index.php?page=Thread&threadID=256 |access-date=2017-01-09 |url-status=dead |archive-url=https://web.archive.org/web/20170110015818/http://s266590939.online.de/Infobase/WBB_317/index.php?page=Thread&threadID=256 |archive-date=2017-01-10}}</ref> Negotiations to make PC/GEOS an integral part of [[PC DOS 7.0]] failed.

GeoWorks attempted to get third-party developers but was unable to get much support due to expense of the developer kit, which cost $1,000 for the manuals only, and the difficult programming environment, which required a second PC networked via serial port to run the debugger.

Even though PC/GEOS is referred to as an "operating system", it still requires DOS in load. GEOS and its applications were written in a mix of 8086 [[assembly language]] (Espire), an interpreted language called [[IZL (programming language)|IZL]], and [[C (programming language)|C]] (GEOS Object C: GOC) with non-standard language extensions to support the [[Object-oriented programming|object-oriented]] design.<ref name="Loli"/><ref>{{cite web |title=PC/GEOS FAQ List part 2/2: Programmer's Questions |editor-last=Bearden |editor-first=James D. "Wiffleguy" |date=1995-05-14 |at=Section 2.1.1 |quote=either of two languages: one is called GOC (GEOS Object C), and the other is Esp (an object-oriented assembly language based on the 8086 assembly instruction set) |url=http://www.uni-giessen.de/faq/archiv/pcgeos-faq.part1-2.old/msg00001.html |url-status=dead |archive-url=https://web.archive.org/web/20090819082953/http://www.uni-giessen.de/faq/archiv/pcgeos-faq.part1-2.old/msg00001.html |archive-date=2009-08-19 |access-date=2011-11-02}}</ref>

Under [[DR DOS 6.0]], if TASKMAX was loaded before PC/GEOS, PC/GEOS registered as graphical menu system for TASKMAX.<ref name="Caldera_1997_MULTI">{{cite book |author=Caldera, Inc. |author-link=Caldera, Inc. |title=OpenDOS Developer's Reference Series: Multitasking API: Programmer's Guide |location=UK |date=August 1997 |id=Caldera Part No. 200-DODG-004 |url=http://www.drdos.net/documentation/multtask/ |access-date=2013-03-21 |url-status=dead |archive-url=https://web.archive.org/web/20171007025548/http://www.drdos.net/documentation/multtask/ |archive-date=2017-10-07}}</ref> This still worked under the pre-emptive multitasker ([[EMM386]] /MULTI + TASKMGR) provided by [[Novell DOS 7]], [[OpenDOS 7.01]] and [[DR-DOS 7.02]] (and higher), allowing for multiple GEOS and DOS applications to run concurrently.<ref name="Paul_1997_NWDOSTIP">{{cite book |title=NWDOS-TIPs: Tips & Tricks rund um Novell DOS 7, mit Blick auf undokumentierte Details, Bugs und Workarounds |work=MPDOSTIP |last=Paul |first=Matthias R. |date=1997-07-30 |orig-year=1994 |edition=3 |version=Release 157 |language=de |url=http://www.antonis.de/dos/dos-tuts/mpdostip/html/nwdostip.htm |access-date=2014-08-06 |url-status=live |archive-url=https://web.archive.org/web/20161104235829/http://www.antonis.de/dos/dos-tuts/mpdostip/html/nwdostip.htm |archive-date=2016-11-04}} (NB. NWDOSTIP.TXT is a comprehensive work on [[Novell DOS 7]] and [[OpenDOS 7.01]], including the description of many undocumented features and internals. It is part of the author's yet larger <code>MPDOSTIP.ZIP</code> collection maintained up to 2001 and distributed on many sites at the time. The provided link points to a HTML-converted older version of the <code>NWDOSTIP.TXT</code> file.)</ref>

After the release of Ensemble 2.01, GeoWorks ended support for the desktop version to focus on handhelds and smart devices.

Geoworks Ensemble won the 1991 [[Software Publishers Association]] Excellence in Software Award for Best Consumer Program.<ref name="cgw199106">{{cite magazine |url=http://www.cgwmuseum.org/galleries/index.php?year=1991&pub=2&id=83 |title=Celebrating Software |magazine=Computer Gaming World |date=June 1991 |access-date=2013-11-17 |page=64}}</ref>

=== NewDeal Office ===
{{anchor|NDO|Skipper|Skipper 2000}}
A newer version of PC/GEOS was marketed in the late 1990s as ''NewDeal Office'' from NewDeal Inc. in hopes of creating a market among owners of [[i386]], [[i486]], and [[Pentium (original)|Pentium]] PCs that could not run [[Windows 95]] or [[Windows 98]] effectively.<ref>{{cite web |url=http://geos-infobase.de/GEOS25.HTM |title=NewDeal Office 2.5 |website=GEOS-InfoBase |language=de |access-date=2021-04-22}}</ref> NewDeal released 3 new versions of NewDeal Office (NewDeal Office 2.5, NewDeal Office 3/98 and NewDeal Office 2000) until it went bankrupt in 2000. NDO or NDO 2000 came with a webbrowser named Skipper or Skipper 2000, respectively.

=== Breadbox Ensemble ===
{{anchor|WebMagick}}
After "NewDeal Inc." went out of business, Breadbox purchased the rights in the software from GeoWorks in 2001.<ref>{{cite web |url=http://www.breadbox.com/newsdetail.asp?id=40 |title=Breadbox Pens GEOS Exclusive License and Ownership Rights Agreement with Geoworks |date=2003-04-29 |publisher=Breadbox Computer Company |url-status=dead |archive-url=https://web.archive.org/web/20080822184337/http://breadbox.com/newsdetail.asp?id=40 |archive-date=2008-08-22}}</ref> Their newest PC/GEOS, 4.x, is now a full productivity and internet suite, including web browser (named WebMagick) as well as email. Other essential programs such as word processing, spreadsheet, flat file database and graphics applications are integrated into this package.

On 14 November 2015, Frank S. Fischer, the CEO and owner of Breadbox Ensemble LLC, died of a heart attack, some while after announcing plans to bring GEOS to Android.<ref name="Yu_2015"/><ref name="Obit_2015"/><ref name="Brown_2016"/>

=== Versions ===
{{anchor|OS/90|GeoDOS}}
* 1990: OS/90 beta version
* 1990: geoDOS beta version
* 1990: GeoWorks 1.0
* 1991: GeoWorks 1.2
* 1992: GeoWorks 1.2 Pro (with [[Borland]] [[Quattro Pro]] for DOS with PC/GEOS "Look and Feel")
* 1992: GeoWorks DTP
* 1992: GeoWorks CD Manager
* 1993: GeoWorks Ensemble 2.0 (new kernel PC/GEOS 2.0)
* 1993: Geopublish 2.0
* 1994: Geoworks Ensemble 2.01
* 1996: NewDeal Office 2.2
* 1996: NewDeal Office 2.5
* 1996: NewDeal Publish 2.5 [[shareware]] version
* 1997: NewDeal Office 97
* 1998: NewDeal Office 98
* 1999: NewDeal Office release 3 (new kernel PC/GEOS 3.0)
* 1999: NewDeal Office release 3 evaluation
* 1999: NewDeal Office 3.2
* 2000: NewDeal Office 3.2d (German patch)
* 2000: NewDeal Office 2000 (new kernel PC/GEOS 4.0)
* 2000: NewDeal Office 2000 for {{Interlanguage link|GlobalPC|de}} (for a Surf´n´Office PC from [[Robert Edward "Teddy" Turner IV|Ted Turner IV]] ([[MyTurn]], Inc.) with help from [[CNN]])
* 2001: BreadBox Ensemble beta version 4.0.1.1
* 2001: BreadBox Ensemble beta version 4.0.1.x
* 2002: Breadbox Ensemble beta version 4.0.2.0
* 2005–March: Breadbox Ensemble version 4.1.0.0
* 2005–November: Breadbox Ensemble version 4.1.2.0
* 2009–August: Breadbox Ensemble version 4.1.3.0

== PEN/GEOS ==
PEN/GEOS 1.0 was the new name for PC/GEOS 2.0 when GeoWorks released it on 9 April 1992.  PEN/GEOS 1.0 was a pioneering [[personal digital assistant]] (PDA) technology.<ref name="Butter2002"/> GEOS was also used in the low-end GeoBook [[laptop]] from [[Brother Industries]] and in several [[Nokia Communicator]] models (GEOS 3.0 in models [[Nokia 9000 Communicator|9000, 9110]]). PEN/GEOS 2.0 was released in 1992, and version 3.0 was released in 1995.

=== ''Zoomer'' devices; Tandy Z-PDA, AST GRiDPad 2390, Casio Z-7000 & XL 7000 ===
PEN/GEOS 1.0 was used as the operating system for the [[Tandy Corporation]] Z-PDA,<ref>{{cite web |url=http://support.radioshack.com/productinfo/DocumentResults.asp?sku_id=25-3100&Name=Tandy%20PDAs&Reuse=N |title=Tandy Z-PDA Catalog #25-3100 |date=2004-10-25 |publisher=[[RadioShack]] |access-date=2014-05-01  |archive-date=2014-05-01  |archive-url=https://web.archive.org/web/20140501210129/http://support.radioshack.com/productinfo/DocumentResults.asp?sku_id=25-3100&Name=Tandy%20PDAs&Reuse=N |url-status=dead }}</ref> which was introduced shortly after the first [[Apple Newton MessagePad]]. [[Palm Computing]] had been incorporated to create software for this device<ref>{{cite web |url=http://www.8bit-micro.com/tandy-zoomer-z-pda.htm |title=The Tandy ZOOMER |date=2004 |last=Hahn |first=Brian K. |access-date=2014-05-01 |archive-url=https://web.archive.org/web/20090207122037/http://www.8bit-micro.com/tandy-zoomer-z-pda.htm |archive-date=2009-02-07 |url-status=dead}}</ref> and shipped its first handwriting recognition software, PalmPrint, [[personal information manager]], Palm Organizer, and synchronization software, PalmConnect,<ref name="Butter2002">{{Cite book |last1=Butter |first1=Andrea |last2=Pogue |first2=David |author-link2=David Pogue |date=2002 |title=Piloting Palm: The Inside Story of Palm, Handspring, and the Birth of the Billion-Dollar Handheld Industry |publisher=[[John Wiley & Sons]] |isbn=978-0-47122339-9 |page=[https://archive.org/details/pilotingpalminsi00butt/page/56 56] |url=https://archive.org/details/pilotingpalminsi00butt |url-access=registration}}</ref> on the Z-PDA. Palm Organizer included the PalmSchedule date book, PalmAddress address book, PalmNotes notebook, a dictionary, calculator, clock, forms calculator, 26 language translation dictionary, on-line help, holiday, and travel information.<ref>{{cite book |title=GRiDPad 2390 User's Manual |publisher=[[AST Research, Inc.]] |url=http://research.microsoft.com/en-us/um/people/bibuxton/buxtoncollection/a/pdf/AST%20Gridpad%202390.pdf#Page=7 |access-date=2014-05-01}}</ref><ref>{{cite web |url=http://www.grot.com/zoomer/documents/tandy-specs.html |title=Zoomer Technical Info; Tandy Z-PDA |date=1995-05-09 |access-date=2014-04-30 |last=Smithson |first=Brian}}</ref><ref>{{cite web |url=http://www.grot.com/zoomer/pictures.html#palm |title=Zoomer Pictures; application screen shots |date=1996-01-17 |last=Smithson |first=Brian}}</ref> The device was also sold under license as the AST GRiDPad 2390<ref>{{cite web |url=http://research.microsoft.com/en-us/um/people/bibuxton/buxtoncollection/detail.aspx?id=31 |title=Buxton Collection; GRiDPad 2390 |access-date=2014-05-01 |last=Buxton |first=Bill |publisher=[[Microsoft Research]] |quote=This <nowiki>[GRiDPad 2390]</nowiki> device is one of three identical Zoomer devices—the other two being the Casio Z-7000 and the Tandy Z-PDA—developed by Palm. This is their first product. The Zoomer failed, but turned out to be the stepping stone that led to the success of the Palm Pilot.}}</ref> and as the Casio Z-7000 which was the best selling version. In the US, Casio sold it under the name XL-7000 without the multi-lingual interface, but added an AOL client and some USA specific help files. These devices were all named ''Zoomer'' and were the first PDAs with a connection to the online services [[CompuServe]] and [[AOL]]. This was made possible through the pre-installed dial-up software CompuServeAOL.

=== HP OmniGo 100 & 120 ===
In 1993, GeoWorks released PEN/GEOS 2.0, again based on PC/GEOS 2.0. In 1995, this version of GEOS appeared (running on top of DOS) on the [[HP OmniGo 100]]. It featured [[Graffiti (Palm OS)|Graffiti]] handwriting recognition. The OmniGo is a flip-around clamshell handheld computer powered by a [[Vadem VG230]] integrated PC-on-a-chip. The VG230 chip includes an [[Intel 80186]]-instruction set compatible [[NEC V30]] core. It was soon followed by the [[HP OmniGo 120]], which added a high-contrast screen.

=== Brother LW-Writing System ===
[[Brother Industries|Brother]] LW-screen typewriters use PEN/GEOS and are the only version of the operating system that ships with vendor-provided drivers for scanner and it included a GEOS scanning application. In Germany, the Brother LW750ic system is equipped with PEN/GEOS.

=== Brother GeoBook ===
In 1997, Brother, in collaboration with IBM, brought the GeoBook series of notebooks to market. GeoBook models NB-60, NB-80C, and PN-9100GR used a modified version of PEN/GEOS using the Yago user interface. The GeoBook series was marketed mainly in education and was part of the ''IBM Eduquest School View'' strategy.

=== Nokia Communicator 9000(i) and 9110(i) ===
In 1996, the [[Nokia 9000 Communicator]] smartphone was introduced. This phone uses PEN/GEOS 3.0 and established the smartphone market. Nokia followed with Communicator models 9000i, 9110, and 9110i.

== GEOS-SC ==
{{Expand section|date=August 2009}}
GEOS-SC was a 32-bit [[reduced instruction set computer]] (RISC) CPU [[smartphone]], OS, and GUI for the Japanese cellphone market. It was released in 1997. Originally built as GeoWorks' planned future OS and codenamed 'Liberty', GEOS-SC became the basis for cellphones designed by [[Mitsubishi Electric]] Company (MELCO) of Japan.

== GEOS-SE ==
{{anchor|Eden OS}}
{{Expand section |date=May 2010}} Alongside this, GEOS-SE which was an OS designed and developed by Eden Ltd., a UK-based company acquired in 1997 by Geoworks<!--, was also a 32-bit RiSC OS{{Citation needed|date=March 2011}} and -> changed to ". It" as "RiSC OS" is probably wrong (and confuses with another OS, "RISC OS"); hard to find, Googling found only a copy of this section of the Wikipedia page -->. It became the basis of several other devices, most notably the Seiko Epson Locatio which was a multifunction device incorporating browser, PIM software, phone, GPS and Camera. It was launched in Japan in 1998.

== FreeGEOS ==
Since 2016, the [[source code]] of PC/GEOS has been made available as FreeGEOS and can be [[Compiler|compiled]] and edited freely.<ref>{{Cite web |last1=Witkowiak |first1=Maciej |last2=Steil |first2=Michael |title=blueway.Softworks: pcgeos |date=29 January 2017 |url=https://github.com/bluewaysw/pcgeos |website=GitHub |access-date=2021-04-22}}</ref>

== References ==
{{Reflist|refs=
<ref name="Yu_2015">{{cite web |title=Frank Fischer, CEO of Breadbox Computing (owner of the GEOS OS), passes away |author=yu/ratthing |date=2015 |url=https://www.reddit.com/r/vintagecomputing/comments/3t6cbu/frank_fischer_ceo_of_breadbox_computing_owner_of/ |access-date=2019-12-20 |url-status=live |archive-url=https://web.archive.org/web/20161108213915/https://www.reddit.com/r/vintagecomputing/comments/3t6cbu/frank_fischer_ceo_of_breadbox_computing_owner_of/?st=iva0rlxm&sh=2148838d |archive-date=2016-11-08}}</ref>
<ref name="Obit_2015">{{cite web |title=Obituary: FISCHER, Frank S. |date=2015-11-17 |publisher=Tampa Bay Times |url=http://www.legacy.com/obituaries/sptimes/obituary.aspx?n=frank-s-fischer&pid=176527846&fhid=3790 |url-status=live |archive-url=https://web.archive.org/web/20161108213737/http://www.legacy.com/obituaries/sptimes/obituary.aspx?n=frank-s-fischer&pid=176527846&fhid=3790 |archive-date=2016-11-08}}</ref>
<ref name="Brown_2016">{{cite web |title=BreadBox President & Founder Dies |date=2016-08-13 |last=Brown |first=Sam |url=https://sites.google.com/site/geosresource/news/breadboxpresidentfounderdies |url-status=dead |archive-url=https://web.archive.org/web/20161108214025/https://sites.google.com/site/geosresource/news/breadboxpresidentfounderdies |archive-date=2016-11-08}}</ref>
}}

==Further reading==
* GEOWORKS. (1990). "Product Packaging (a printed card box with corrugated card liner) Part number: 16-2001-0101 Bar Code: 0 14233 20010 6". GeoWorks, Berkeley, CA 94704.
* Oerttel, Burkhard. ''Das große Buch zu GeoWorks Pro, Ensemble & DTP'', Data Becker GmbH, 1992, {{ISBN|3-89011-586-1}}.
* Oerttel, Burkhard. ''Das große Buch zu GeoWorks 2.0'', Data Becker GmbH, 1994, {{ISBN|3-89011-713-9}}.
* Wegen, Andreas. ''GeoWorks DTP, Pro, Ensemble'', te-wi Verlag bzw. TLC The Learning Companie, Series: Grundlagen und Praxis - Betriebssysteme, 1992, {{ISBN|3-89362-238-1}}.
* Wegen, Andreas. ''GeoWorks 2.0 - Bedienung, Applikationen, Beispiele, Tips, Interna, Referenz'', te-wi Verlag, 1993, {{ISBN|3-89362-333-7}}.
* Seibert, Axel. ''GeoWorks - Ensemble Erfolgreich starten - sicher nutzen'', Markt & Technik Verlag München, Series: Workshop - PC, 1991, {{ISBN|3-87791-154-4}}.
* Roßkamp, Alfred. ''GeoWorks Ensemble - Einführung in die Benutzerschnittstelle'', Deutscher Taschenbuch Verlag (dtv), Series: Beck EDV-Berater im dtv (Basiswissen - GeoWorks), 1993, {{ISBN|3-423-50152-9}}.
* Bartel, Rainer. ''GeoWorks 1.2 & Pro - Der Einstieg in 20 Schritten'', Sybex Verlag Düsseldorf, Series: Quick Start, 1992, {{ISBN|3-88745-230-5}}.
* Schölles, Reiner. ''GeoWorks 2.0 - Schnellanleitung'', Data Becker GmbH, 1994, {{ISBN|3-89011-787-2}}.
* {{cite newsgroup |title=GEOS/NDO info for RBIL62? |author-first1=Matthias R. |author-last1=Paul 
|author-first2=Edward "Ed" |author-last2=Di Geronimo, Jr. |author-first3=Marcus |author-last3=Groeber |author-first4=Jens-Michael |author-last4=Gross |date=2002-03-02 |orig-date=2002-02-21 |newsgroup=comp.os.geos.programmer |url=https://groups.google.com/d/msg/comp.os.geos.programmer/8NNPJ4VU23A/cucVV95kf9oJ |access-date=2019-04-20 |url-status=live |archive-url=https://archive.today/20190420111421/https://groups.google.com/forum/%23!msg/comp.os.geos.programmer/8NNPJ4VU23A/cucVV95kf9oJ |archive-date=2019-04-20}}

==External links==
* Usenet
** {{Usenet|comp.os.geos.misc|comp.os.geos.misc}}
** {{Usenet|comp.os.geos.programmer|comp.os.geos.programmer}}
* [https://web.archive.org/web/20160305003829/http://www.breadbox.com/ Breadbox Computer Company], former developer and publisher of GEOS
* [http://www.faqs.org/faqs/pcgeos-faq/ GEOS FAQ]
* [http://www.geos-infobase.de/ GEOS-InfoBase]
* {{GitHub|bluewaysw/pcgeos|PC/GEOS}}
* {{Official website|blog.bluewaysw.de}} blueway.Softworks

{{Mobile operating systems}}

{{DEFAULTSORT:Geos (16-Bit Operating System)}}
[[Category:DOS software]]
[[Category:Formerly proprietary software]]
[[Category:Graphical user interfaces]]
[[Category:Mobile operating systems]]
[[Category:Operating system APIs]]
[[Category:Software using the Apache license]]
[[Category:Assembly language software]]
[[Category:Window-based operating systems]]
[[Category:X86 operating systems]]
[[Category:1990 software]]

[[cs:GEOS]]