Editing Konrad Zuse (section)

===1945–1995===
After the 1945 Luisenstadt bombing, he fled from Berlin to the rural [[Allgäu]].<ref>{{Cite web |title=Konrad Zuse im Schloss zu Hopferau |url=https://www.hopferau.de/konrad-zuse.html |access-date=28 October 2023 |website=www.hopferau.de}}</ref> In the extreme deprivation of [[Allied-occupied Germany|post-war Germany]] Zuse was unable to build computers.

Zuse founded one of the earliest computer companies: the {{lang|de|italic=no|Zuse-Ingenieurbüro Hopferau}}. Capital was raised in 1946 through [[ETH Zurich]] and an IBM option on Zuse's patents.<ref>{{Cite web |last=Schmidhuber |first=Jürgen |date=19 August 2021 |title=1941: Konrad Zuse completes the first working general-purpose computer, based on his 1936 patent application |url=https://people.idsia.ch/~juergen/zuse-1941-first-general-computer.html |website=Universita della Svizzera Italiana}}</ref>

In 1947, according to the memoirs of the German computer pioneer [[Heinz Billing]] from the [[Max Planck Institute for Physics]], there was a meeting between [[Alan Turing]] and Konrad Zuse in [[Göttingen]].<ref>{{cite web|url=http://www.mathcomp.leeds.ac.uk/turing2012/Images/Turing_Zuse.pdf|title=Did Alan Turing interrogate Konrad Zuse in Göttingen in 1947?|author=Bruderer, Herbert|access-date=7 February 2013|archive-date=21 May 2013|archive-url=https://web.archive.org/web/20130521211106/http://www.mathcomp.leeds.ac.uk/turing2012/Images/Turing_Zuse.pdf|url-status=dead}}</ref> The encounter had the form of a [[Academic conference|colloquium]]. Participants were [[John R. Womersley|Womersley]], Turing, Porter from England and a few German researchers like Zuse, Walther, and Billing. (For more details see Herbert Bruderer, {{lang|de|Konrad Zuse und die Schweiz}}).
 
It was not until 1949 that Zuse was able to resume work on the Z4. He would show the computer to the mathematician [[Eduard Stiefel]] of the ETH Zurich. The two men settled a deal to lend the Z4 to the ETH.<ref name="Lippe_2007">{{Cite web |title=Kapitel 14 – Die ersten programmierbaren Rechner |author-last=Lippe |author-first=Wolfram M. |date=13 April 2010 |orig-date=2007 |language=de |url=http://cs.uni-muenster.de/Professoren/Lippe/lehre/skripte/geschichte/pdf/Kap14.pdf |access-date=21 June 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110719110029/http://cs.uni-muenster.de/Professoren/Lippe/lehre/skripte/geschichte/pdf/Kap14.pdf |archive-date=19 July 2011
|quote=[in 1949 Professor Stiefel from ETH Zürich] was not a little surprised when he found the Z4, which was already a bit battered from the outside, set up in a horse stable. Nevertheless, he dictated to Zuse a simple differential equation that Zuse could immediately program, demonstrate on the machine and solve. After that he concluded a contract with Zuse: the Z4 should be loaned to the ETH after a thorough overhaul and cleaning.}}</ref>

[[File:Zuse-Werkstatt-Neukirchen-Jan-2010.jpg|right|thumb|Zuse's workshop at Neukirchen, 2010]]
In November 1949, Zuse founded another company, Zuse KG, in [[Haunetal|Haunetal-Neukirchen]]; in 1957, the company's head office moved to [[Bad Hersfeld]]. The [[Z4 (computer)|Z4]] was finished and delivered to the ETH Zurich in July 1950, where it proved very reliable.<ref name="HZ2010-11-18" /> At that time, it was the only working digital computer in Central Europe,<ref>Bruderer (2021), p. 1098</ref> and the second computer in the world to be sold or loaned, beaten only by the [[BINAC]], which never worked properly after it was delivered. Other computers, all numbered with a leading Z, up to Z43,<ref>{{cite web |url=http://epemag.com/zuse/part7e.htm |title=Part 7 (continued): The Zuse KG |access-date=4 July 2011 |url-status=unfit |archive-url=https://web.archive.org/web/20090511021714/http://epemag.com/zuse/part7e.htm |archive-date=11 May 2009 }} Horst Zuse, EPE Online, archived on 11 May 2009 from [http://www.epemag.com/zuse/part7e.htm the original] {{Webarchive|url=https://web.archive.org/web/20081228103304/http://www.epemag.com/zuse/part7e.htm |date=28 December 2008 }}</ref> were built by Zuse and his company. Notable are the [[Z11 (computer)|Z11]], which was sold to the optics industry and to universities, and the [[Z22 (computer)|Z22]], the first computer with a memory based on magnetic storage.<ref>{{cite web|url=http://www.epemag.com/zuse/ |title=The Life and Work of Konrad Zuse |access-date=18 April 2010 |url-status=unfit |archive-url=https://web.archive.org/web/20090629003415/http://www.epemag.com/zuse/ |archive-date=29 June 2009 }} Horst Zuse, EPE Online, archived on 29 June 2009 from [http://www.epemag.com/zuse/ the original] {{webarchive |url=https://web.archive.org/web/20100418164050/http://www.epemag.com/zuse/ |date=18 April 2010 }}</ref>

Unable to do any hardware development, he continued working on {{lang|de|italic=no|Plankalkül}}, eventually publishing some brief excerpts of his thesis in 1948 and 1959; the work in its entirety, however, remained unpublished until 1972.<ref name="knuthpardo"/> The PhD thesis was submitted at [[University of Augsburg]], but it was rejected because Zuse forgot to pay the [[Deutsche Mark|DM]]&nbsp;400 university enrollment fee. The rejection did not bother him.<ref>{{cite web |url=https://www.get-it.tu-berlin.de/menue/werdegaenge/ursula_walk/ |title=Ursula Walk, geb. 1925 |website=www.get-it.tu-berlin.de |archive-url=https://web.archive.org/web/20181116041955/https://www.get-it.tu-berlin.de/menue/werdegaenge/ursula_walk/ |archive-date=16 November 2018 }}</ref> 

{{lang|de|italic=no|Plankalkül}} slightly influenced the design of [[ALGOL 58]]<ref>{{cite book |last1=Rojas|first1=Raúl|first2=Ulf|last2=Hashagen| date=2002 |title=The First Computers: History and Architectures|page=292 |url=https://books.google.com/books?id=nDWPW9uwZPAC&q=algol-68+konrad+zuse&pg=PA292 |publisher=MIT Press |isbn=978-0-262-68137-7 |access-date=25 October 2013 }}</ref> but was itself implemented only in 1975 in a dissertation by Joachim Hohmann.<ref>Joachim Hohmann: ''Der Plankalkül im Vergleich mit algorithmischen Sprachen''. Reihe Informatik und Operations Research, S. Toeche-Mittler Verlag, Darmstadt 1979, {{ISBN|3-87820-028-5}}.</ref> [[Heinz Rutishauser]], one of the inventors of [[ALGOL]], wrote: "The very first attempt to devise an [[algorithm]]ic language was undertaken in 1948 by K. Zuse. His notation was quite general, but the proposal never attained the consideration it deserved." Further implementations followed in 1998 and then in 2000 by a team from the [[Free University of Berlin]]. [[Donald Knuth]] suggested a [[thought experiment]]: What might have happened had the bombing not taken place, and had the PhD thesis accordingly been published as planned?<ref name=knuthpardo/>{{relevant|reason=A thought "experiment" is presented, but no relevant result or conclusion. This is of no greater interest than any other arbitrary "what if" question. |date=May 2025}}

[[File:Zuse Z64 Graphomat.jpg|alt=Z64 Graphomat plotter|thumb|Z64 Graphomat plotter]]
In 1956, Zuse began to work on a high precision, large format [[plotter]]. It was demonstrated at the 1961 [[Hanover Fair]],<ref name=HorstZuse>{{cite web|url=http://www.horst-zuse.homepage.t-online.de/z64.html|title=Graphomat Z64 (in German)|website=www.zuse.de}}</ref> and became well known also outside of the technical world thanks to [[Frieder Nake]]'s pioneering computer art work.<ref>{{cite web|url=http://www.heikewerner.com/nake_en.html|title=Pioneer Work: Frieder Nake|website=www.heikewerner.com}}</ref> Other plotters designed by Zuse include the ZUSE Z90 and ZUSE Z9004.<ref name=HorstZuse/>

[[File:Digitalteilchen.svg|thumb|upright=0.7|left|An elementary process in Zuse's Calculating Space: Two digital particles A and B form a new digital particle C.<ref>[ftp://ftp.idsia.ch/pub/juergen/zuse67scan.pdf ''Rechnender Raum''] (PDF), Elektronische Datenverarbeitung, 8: 336–344, 1967.</ref>]]
In 1967, Zuse suggested that the [[universe]] itself is running on a [[cellular automaton]] or similar computational structure ([[digital physics]]); in 1969, he published the book {{lang|de|Rechnender Raum}} (translated into English as ''[[Calculating Space]]'').<ref name="Zuse_1967_RR"/><ref name="Zuse_1969_RR"/><ref name="MIT_1970_RR"/>

{{anchor|Helixturm}}Between 1989 and 1995, Zuse conceptualized and created a purely mechanical, extensible, modular tower automaton he named "helix tower" ({{lang|de|"Helixturm"}}). The structure is based on a gear drive that employs rotary motion (e.g. provided by a crank) to assemble modular components from a storage space, elevating a tube-shaped tower; the process is reversible, and inverting the input direction will deconstruct the tower and store the components. In 2009, the {{lang|de|italic=no|[[Deutsches Museum]]}} restored Zuse's original 1:30 functional model that can be extended to a height of 2.7&nbsp;m.<ref name="DM_2015"/> Zuse intended the full construction to reach a height of 120&nbsp;m, and envisioned it for use with wind power generators and radio transmission installations.<ref name="Eibisch_2009"/><ref name="Bock-Eibisch_2010"/><ref name="Böttiger_2011"/><ref name="Eibisch_2016"/>

Between 1987 and 1989, Zuse recreated the Z1, suffering a heart attack midway through the project. It cost 800,000&nbsp;[[Deutsche Mark|DM]] (approximately $500,000) and required four individuals (including Zuse) to assemble it. Funding for this [[retrocomputing]] project was provided by [[Siemens]] and a consortium of five companies.<ref>{{Cite web |last=Rojas |first=Paul |date=August 2015 |title=Reconstruction of the Z1 Computer |url=https://dcmlr.inf.fu-berlin.de/rojas/index.html%3Fp=567.html |archive-url=https://web.archive.org/web/20231015074346/https://dcmlr.inf.fu-berlin.de/rojas/index.html%3Fp=567.html |archive-date=15 October 2023 |website=Paul Rojas, Professor of Artificial Intelligence}}</ref>