Editing Z4 (computer)

{{Short description|German 1940s computer}}
{{Use dmy dates|date=October 2020|cs1-dates=y}}
{{Use list-defined references|date=July 2022}}
{{Infobox information appliance
| name         = Z4
| image        = Zuse-Z4-Totale deutsches-museum b.jpg
| caption      = Z4 on display at the [[Deutsches Museum]], [[Munich]]
| developer    = [[Konrad Zuse]]
| manufacturer = [[Zuse Apparatebau]]
| type         = [[Computer programming|Programmable]], fully automatic [[digital computer|digital]] [[electromechanical computer]]
| releasedate  = {{Start date and age|1945}}
| price        = {{CHF|30,000|1950|link=yes}} for five years
| unitssold    = 1 (to [[ETH Zurich]] in a loan deal)<ref name="Bruderer_2021"/>{{rp|pages=1077, 1139}}
| power        = (about) 4&nbsp;[[Kilowatt|kW]]
| CPUspeed     = (about) 40&nbsp;[[Hertz|Hz]]
| memory       = Mechanical, 32 bits word length
| display      = Decimal floating point numbers, [[punch tape]] or ''Mercedes'' [[typewriter]]
| input        = Decimal floating point numbers, punch tape
| weight       = Ca. {{convert|1000|kg|lb|abbr=on|lk=on}}
| predecessor  = [[Z3 (computer)|Z3]]
| successor    = [[Z5 (computer)|Z5]]
}}
The '''Z4''' was arguably the world's first commercial [[digital computer]], and is the oldest surviving programmable computer.<ref name="Bruderer_2021"/>{{rp|page=1028}} It was designed, and manufactured by early computer scientist [[Konrad Zuse]]'s company ''Zuse Apparatebau'', for an order placed by [[Henschel & Son]], in 1942; though only partially assembled in Berlin, then completed in Göttingen in the [[Third Reich]] in April 1945,<ref name="Schillo_2001"/> but not delivered before the defeat of Nazi Germany, in 1945.<ref name="Zuse_2000"/><ref name="Kaisler_2016"/><ref name="Sommaruga-Strahm_2016"/> The Z4 was Zuse's final target for the [[Z3 (computer)|Z3]] design.<ref name="Rojas_2006"/> Like the earlier [[Z2 (computer)|Z2]], it comprised a combination of mechanical memory and [[Electromechanics|electromechanical]] logic.<ref name="Zuse_1993"/>

The Z4 was used at the [[ETH Zurich]] from 1950 to 1955,<ref name="Bruderer_2021"/>{{rp|page=14}} also serving as the inspiration for the construction of the [[ERMETH]],<ref name="Bruderer_2021"/>{{rp|page=1009}} the first Swiss computer, created under the direction of ETH engineer [[Ambros Speiser]].<ref name="Bruderer_2021"/>{{rp|page=1087}}

==Construction==
[[File:Elektromagnetischesrelais zuse 1940 denis apel cc.jpg|thumb|Electromagnetic relay of the Z4]]
The Z4 was very similar to the [[Z3 (computer)|Z3]] in its design but was significantly enhanced in a number of respects. The memory consisted of 32-bit rather than 22-bit [[floating point]] [[Word (computer architecture)|words]]. The Program Construction Unit (''Planfertigungsteil'') punched the program tapes, making programming and correcting programs for the machine much easier by the use of symbolic operations and memory cells. Numbers were entered and output as decimal floating-point even though the internal working was in binary. The machine had a large repertoire of instructions including square root, MAX, MIN and sine. Conditional tests included tests for infinity. When delivered to [[ETH Zurich]] in 1950 the machine had a conditional branch facility added<ref name="Rojas_2014"/> and could print on a Mercedes typewriter. There were two program tapes where the second could be used to hold a subroutine. (Originally six were planned.)<ref name="Speiser-Rojas-Hashagen_2002"/><ref name="Lyndon_1947"/>

In 1944, Zuse was working on the Z4 with around two dozen people,<ref name="Bauer_2009"/> including [[Wilfried de Beauclair]]. Some engineers who worked at the telecommunications facility of the [[Oberkommando der Wehrmacht|OKW]] also worked for Zuse as a secondary occupation. Also in 1944 Zuse transformed his company to the ''Zuse KG'' (''[[Kommanditgesellschaft]]'', i.e. a limited partnership) and planned to manufacture 300 computers.<ref name="Hellige-Petzold_2004"/> This way he could also request additional staff and scientists as a contractor in the [[Emergency Fighter Program]].<ref name="Hellige-Petzold_2004"/> Zuse's company also cooperated with [[Alwin Walther]]'s Institute for Applied Mathematics at the [[Technische Universität Darmstadt]].<ref name="deBeauclair_1986"/>

To prevent it from falling into the hands of the Soviets, the Z4 was evacuated from [[Berlin]] in February 1945 and transported to [[Göttingen]].<ref name="Bauer_2009"/><ref name="Zuse_2010-11-18"/> The Z4 was completed in Göttingen in a facility of the ''Aerodynamische Versuchsanstalt'' (AVA, Aerodynamic Research Institute), which was headed by [[Albert Betz]]. But when it was presented to scientists of the AVA the roar of the approaching front could already be heard,<ref name="Schillo_2001"/> so the computer was transported with a truck of the [[Wehrmacht]] to Hinterstein in [[Bad Hindelang]] in southern Bavaria, where Konrad Zuse met [[Wernher von Braun]].<ref name="Schillo_2001"/><ref name="Campbell-Kelly_1995"/>

By 1947 it was possible for constants to be entered by the punched tape.<ref name="Lyndon_1947"/>

==Use after World War II==
In 1949, the Swiss mathematician [[Eduard Stiefel]], after coming back from a stay in the US where he inspected American computers, visited Zuse and the Z4. When he formulated a [[differential equation]] as a test, Zuse immediately programmed the Z4 to solve it. Stiefel decided to acquire the computer for his newly founded [[Seminar for Applied Mathematics|Institute for Applied Mathematics]] at the [[ETH Zurich]].<ref name="Lippe_2007"/> It was delivered to ETH Zurich in 1950.<ref name="DTIC_1951"/><ref name="ACM_1951"/>

{{quote box|align=right|At least Zürich has an interesting nightlife with the rattling of the Z4, even if it is only modest.|—Konrad Zuse}}

In 1954, [[Wolfgang Haack]] tried to obtain the Z4 for [[Technische Universität Berlin]],<ref name="Hellige-Petzold_2004"/> but it was instead transferred to the {{lang|fr|Institut Franco-Allemand des Recherches de St. Louis}} (ISL, Franco-German Institute of Research) in [[France]], where it was in use until 1959, under its technical head [[Hubert Schardin]]. Today, the Z4 is on display in the [[Deutsches Museum]] in [[Munich]]. The Z4 inspired the ETH to build its own computer (mainly by [[Ambros Speiser]] and [[Eduard Stiefel]]), which was called [[ERMETH]], an acronym for {{langx|de|Elektronische Rechenmaschine ETH}} ("Electronic Computing Machine ETH").<ref name="Bruderer_2021"/>{{rp|page=1009}}

In 1950/1951, the Z4 was the only working digital computer in [[Central Europe]], and the second digital computer in the world to be sold or loaned,<ref name="Bruderer_2021"/>{{rp|page=981}} beating the [[Ferranti Mark 1]] by five months and the [[UNIVAC I]] by ten months, but in turn being beaten by the [[BINAC]] (although that never worked at the customer's site<ref name="Schmitt_1988"/>). Other computers, all numbered with a leading Z, 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]].

In 1955 the Z4 was sold to the French-German Research Institute of Saint-Louis (''Institut franco-allemand de recherches de Saint-Louis'') in [[Saint-Louis, Haut-Rhin|Saint-Louis]], close to Basel, and in 1960 transferred to the [[Deutsches Museum|German Museum]] in [[Munich]].<ref name="DM_2020"/>

The Z4 was used for calculations for work on the [[Grande Dixence Dam]] in 1950.<ref name="Bruderer_2021"/>{{rp|page=1081}}

==Specifications==
* Frequency: (about) 40&nbsp;[[Hertz|Hz]]
* Average calculation speed: 400&nbsp;[[Millisecond|ms]] for an addition, 3 seconds for a multiplication. Approximately 1000 floating point arithmetic operations on average an hour.
* Programming: holes in 35&nbsp;mm film stock, punched on a programming machine
* Input: Decimal floating point numbers, punch tape
* Output: Decimal floating point numbers, punch tape or Mercedes typewriter
* Word length: 32 bits floating point
* Elements: (about) 2,500 relays, 21 step-wise relays
* Memory: Mechanical memory from the Z1 and Z2<ref name="Zuse_1993"/> (64 words, 32 bit)<ref name="ONR_1953"/>
* Power consumption: (about) 4&nbsp;[[Kilowatt|kW]]

==See also==
* [[Z1 (computer)|Z1]]
* [[History of computing hardware]]
* [[Reverse Polish notation]] (RPN)
* [[Stack machine]]

==References==
{{reflist|refs=
<ref name="Zuse_1993">{{Cite book |title=The Computer - My Life |author-last=Zuse |author-first=Konrad |author-link=Konrad Zuse |date=1993-09-28 |publisher=[[Springer Science & Business Media]] |isbn=978-3-54056453-9 |pages=81 |language=en |url=https://books.google.com/books?id=Ro5JOskbChAC&q=%22z4%22+mechanical+%22main+memory%22&pg=PA81}} (NB. This is a translation of the original title in German {{lang|de|Der Computer - Mein Lebenswerk}}.)</ref>
<ref name="deBeauclair_1986">{{Cite journal |title=Alwin Walther, IPM, and the Development of Calculator/Computer Technology in Germany, 1930–1945 |author-last=de Beauclair |author-first=Wilfried |author-link=Wilfried de Beauclair |date=October 1986 |journal=[[Annals of the History of Computing]] |publisher=[[Institute of Electrical and Electronics Engineers]] |volume=8 |issue=4 |pages=334–350 |issn=0164-1239 |doi=10.1109/MAHC.1986.10061 |s2cid=15020276}}</ref>
<ref name="Zuse_2010-11-18">{{citation |title=Speech |author-first=Horst |author-last=Zuse |author-link=Horst Zuse |location=[[Computer Conservation Society]], [[Science Museum (London)]], London, UK |date=2010-11-18}}</ref>
<ref name="Schillo_2001">{{Cite web |title=Zuse |type=Lecture |language=de |author-last=Schillo |author-first=Michael |author-link=:d:Q102451242 |date=2001 |url=http://www.virtosphere.de/schillo/teaching/WS2001/Vortraege/Zuse.pdf |access-date=2010-06-21 |url-status=live |archive-url=https://web.archive.org/web/20210308081804/http://www.virtosphere.de/schillo/teaching/WS2001/Vortraege/Zuse.pdf |archive-date=2021-03-08}} (25 pages)</ref>
<ref name="Zuse_2000">{{Cite web |title=The Life and Work of Konrad Zuse |author-last=Zuse |author-first=Horst |author-link=Horst Zuse |pages=Part 6: part6a, part6b |no-pp=yes |url=http://www.epemag.com/zuse/default.htm |access-date=2010-05-15 |url-status=dead |archive-url=https://web.archive.org/web/20080616110910/http://www.epemag.com/zuse/default.htm |archive-date=2008-06-16}}</ref>
<ref name="Kaisler_2016">{{Cite book |title=Birthing the Computer: From Relays to Vacuum Tubes |author-last=Kaisler |author-first=Stephen H. |date=2016-12-12 |publisher=[[Cambridge Scholars Publishing]] |isbn=978-1-44389631-3 |pages=14 |language=en |url=https://books.google.com/books?id=oyBUDgAAQBAJ&q=zuse+z4+1945&pg=PA14}}</ref>
<ref name="Sommaruga-Strahm_2016">{{Cite book |title=Turing's Revolution: The Impact of His Ideas about Computability |author-last1=Sommaruga |author-first1=Giovanni |author-last2=Strahm |author-first2=Thomas |date=2016-01-21 |publisher=Birkhäuser |isbn=978-3-31922156-4 |pages=54 |language=en |url=https://books.google.com/books?id=M8ZyCwAAQBAJ&q=%22z4%22+gottingen&pg=PA54}}</ref>
<ref name="Rojas_2006">{{cite news |title=The Zuse Computers |author-last=Rojas |author-first=Raúl |author-link=Raúl Rojas |date=Spring 2006 |orig-date=2005-05-12 |type=edited transscript of speech |location=Computing Before Computers seminar, Science Museum |periodical=[[Resurrection - The Bulletin of the Computer Conservation Society]] |publisher=[[Computer Conservation Society]] (CCS) |issn=0958-7403 |volume=37 |url=http://www.cs.man.ac.uk/CCS/res/res37.htm#c |access-date=2008-07-26 |url-status=live |archive-url=https://web.archive.org/web/20220407104828/http://www.cs.man.ac.uk/ccs/res/res37.htm#c |archive-date=2022-04-07}}</ref>
<ref name="Rojas_2014">{{Cite journal |title=Konrad Zuse und der bedingte Sprung |trans-title=Konrad Zuse and the conditional jump |author-last=Rojas |author-first=Raúl |author-link=Raúl Rojas |date=2014-02-01 |journal=Informatik-Spektrum |language=de |volume=37 |issue=1 |pages=50–53 |doi=10.1007/s00287-013-0717-9 |s2cid=1086397 |issn=0170-6012}}</ref>
<ref name="Speiser-Rojas-Hashagen_2002">{{cite book |title=The first Computers: History and Architectures |chapter=Konrad Zuse's Z4: Architecture, Programming and Modifications at ETH Zurich |author-first=Ambros Paul |author-last=Speiser |author-link=Ambros Paul Speiser |editor-first1=Rául |editor-last1=Rojas |editor-link1=Raúl Rojas |editor-first2=Ulf |editor-last2=Hashagen |editor-link2=:de:Ulf Hashagen |publisher=MIT |date=2002 |isbn=978-0-262-18197-6 |pages=263–276}}</ref>
<ref name="Bauer_2009">{{cite book |title=Historische Notizen zur Informatik |language=de |author-last=Bauer |author-first=Friedrich Ludwig |author-link=Friedrich Ludwig Bauer |publisher=Springer |publication-place=Berlin, Germany |date=2009 |isbn=978-3-540-85789-1 |page=198}}</ref>
<ref name="Hellige-Petzold_2004">{{cite book |title=Geschichten der Informatik. Visionen, Paradigmen, Leitmotive |language=de |editor-first=Hans Dieter |editor-last=Hellige |author-first=Hartmut |author-last=Petzold |author-link=:de:Hartmut Petzold |publisher=Springer |date=2004 |publication-place=Berlin, Germany |isbn=3-540-00217-0 |pages=93, 110}}</ref>
<ref name="Campbell-Kelly_1995">{{cite news |title=Obituary: Konrad Zuse |author-last=Campbell-Kelly |author-first=Martin |author-link=Martin Campbell-Kelly |newspaper=[[The Independent]] |date=1995-12-21 |url=https://www.independent.co.uk/news/people/obituary--konrad-zuse-1526795.html |access-date=2011-02-04}}</ref>
<ref name="Lippe_2007">{{Cite web |title=Kapitel 14 - Die ersten programmierbaren Rechner |author-last=Lippe |author-first=Wolfram M. |date=2010-04-13 |orig-date=2007 |language=de |url=http://cs.uni-muenster.de/Professoren/Lippe/lehre/skripte/geschichte/pdf/Kap14.pdf |access-date=2010-06-21 |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=2011-07-19}}</ref>
<ref name="DTIC_1951">{{Cite journal |title=Zuse Computer Model IV, at Zurich, Switzerland |date=April 1951 |url=https://apps.dtic.mil/sti/citations/tr/AD0694600 |journal=Digital Computer Newsletter |volume=3 |issue=1 |pages=5}}</ref>
<ref name="ACM_1951">{{Cite journal |title=Automatic Computing Machinery: News – Institute for Applied Mathematics of the Swiss Federal Institute of Technology |date=1951 |journal=[[Mathematics of Computation]] |language=en-US |volume=5 |issue=33 |pages=45–46 |doi=10.1090/S0025-5718-51-99443-4 |doi-access=free}}</ref>
<ref name="Schmitt_1988">{{cite web |url=http://www.palosverdes.com/lasthurrah/binac-description.html |title=Description of the BINAC |access-date=2008-07-26}} Citing {{cite journal |author-first=William F. |author-last=Schmitt |title=The UNIVAC SHORT CODE |journal=IEEE Annals of the History of Computing |volume=10 |issue=1 |pages=7–18 [9] |date=1988 |doi=10.1109/MAHC.1988.10004 |s2cid=10189359 |quote=The BINAC}}</ref>
<ref name="DM_2020">[[Deutsches Museum]], [http://www.deutsches-museum.de/sammlungen/meisterwerke/meisterwerke-iii/z3-und-z4/ Die Z3 und Z4 von Konrad Zuse], Website of the [[Deutsches Museum]]</ref>
<ref name="ONR_1953">{{cite book |url=https://archive.org/details/bitsavers_onrASurveyomputers1953_8778395 |title=A survey of automatic digital computers |date=1953 |publisher=Office of Naval Research, Dept. of the Navy |page=[https://archive.org/details/bitsavers_onrASurveyomputers1953_8778395/page/n109 97] |language=en}}</ref>
<ref name="Lyndon_1947">{{Cite journal |author-last=Lyndon |author-first=Roger Conant |author-link=Roger Conant Lyndon |date=1947 |title=The Zuse computer |journal=[[Mathematics of Computation]] |language=en-US |volume=2 |issue=20 |pages=355–359 [359] |doi=10.1090/S0025-5718-1947-0022444-9 |issn=0025-5718 |doi-access=free}}</ref>
<ref name="Bruderer_2021">{{cite book |title=Milestones in Analog and Digital Computing |author-first=Herbert |author-last=Bruderer |publisher=Springer |date=2021 |isbn=978-3-03040973-9 |edition=3rd |pages=981, 1009, 1028, 1077, 1087, 1139}} (NB. This is the English translation of the German work "{{lang|de|Meilensteine der Rechentechnik}}" in two volumes.)</ref>
}}

==Further reading==
* {{Cite book |title=The Origins of Digital Computers: Selected Papers |chapter=Chapter IV: Zuse and Schreyer |author-last=Randell |author-first=Brian |author-link=Brian Randell |date=2012-12-06 |publisher=[[Springer Science & Business Media]] |isbn=978-3-64296242-4 |pages=156–157 |language=en |chapter-url=https://books.google.com/books?id=ouWpCAAAQBAJ&q=zuse+Hopferau+Lyndon&pg=PA156 |access-date=2022-07-02}}
* {{cite book |title=Computer architecture: Concepts and evolution |author-first1=Gerrit Anne |author-last1=Blaauw |author-link1=Gerrit Anne Blaauw |author-first2=Frederick Phillips |author-last2=Brooks, Jr. |author-link2=Frederick Phillips Brooks |publisher=[[Addison-Wesley Longman Publishing Co., Inc.]] |publication-place=Boston, Massachusetts, USA |date=1997}}
* {{cite book |title=Second-Generation Stack Computer Architecture |chapter=2.1 Lukasiewicz and the First Generation: 2.1.2 Germany: Konrad Zuse (1910–1995); 2.2 The First Generation of Stack Computers: 2.2.1 Zuse Z4  |author-first=Charles Eric |author-last=LaForest |type=thesis |publisher=[[University of Waterloo]] |location=Waterloo, Canada |date=April 2007 |pages=8, 11 |url=http://fpgacpu.ca/publications/Second-Generation_Stack_Computer_Architecture.pdf |access-date=2022-07-02 |url-status=live |archive-url=https://web.archive.org/web/20220120155616/http://fpgacpu.ca/publications/Second-Generation_Stack_Computer_Architecture.pdf |archive-date=2022-01-20}} (178 pages)
* {{cite book |author-first=Herbert |author-last=Bruderer |url=http://www.oldenbourg-verlag.de/wissenschaftsverlag/konrad-zuse-und-schweiz/9783486713664 |title=Konrad Zuse und die Schweiz. Wer hat den Computer erfunden? Charles Babbage, Alan Turing und John von Neumann |language=de |publisher=Oldenbourg Verlag |location=Munich, Germany |date=2012 |volume=XXVI |isbn=978-3-486-71366-4 |archive-url=https://web.archive.org/web/20120203000552/http://www.oldenbourg-verlag.de/wissenschaftsverlag/konrad-zuse-und-schweiz/9783486713664 |archive-date=2012-02-03}}
* {{cite web |author-first=Herbert |author-last=Bruderer |title=Discovery: User Manual of the Oldest Surviving Computer in the World |date=2020-09-21 |work=BLOG@CACM |publisher=[[Association for Computing Machinery]] |url=https://cacm.acm.org/blogs/blog-cacm/247521-discovery-user-manual-of-the-oldest-surviving-computer-in-the-world/fulltext |access-date=2022-07-02 |url-status=live |archive-url=https://web.archive.org/web/20220702121207/https://cacm.acm.org/blogs/blog-cacm/247521-discovery-user-manual-of-the-oldest-surviving-computer-in-the-world/fulltext |archive-date=2022-07-02}}
* {{cite book |title=Gebrauchsanweisung Z 4 |language=de |trans-title=User manual Z 4 |author-first=Heinz |author-last=Rutishauser |author-link=Heinz Rutishauser |date=Summer 1952 |publisher=Institut für angewandte Mathematik, ETH Zürich |id=Exemplar Nr. 19, Hs 1517:1 |doi=10.7891/e-manuscripta-98601 |url=https://www.e-manuscripta.ch/zut/doi/10.7891/e-manuscripta-98601 |access-date=2022-07-02 |url-status=live |archive-url=https://web.archive.org/web/20220702121755/https://www.e-manuscripta.ch/zut/doi/10.7891/e-manuscripta-98601 |archive-date=2022-07-02}} [https://web.archive.org/web/20201013163404/https://www.e-manuscripta.ch/download/pdf/2856520?name=Gebrauchsanweisung%20Z4%20Bedienungsanweisung%20f%C3%BCr%20Zuse%20Z4%20verfasst%20am%20Institut%20f%C3%BCr%20a] (1+1+16 pages)

==External links==
* [http://zuse.de zuse.de] homepage from Horst Zuse (son of Konrad Zuse) with much information about the Zuse computers
* [https://web.archive.org/web/20100625154937/http://user.cs.tu-berlin.de/~zuse/Konrad_Zuse/en/index.html zuse.de {English}] English homepage from Horst Zuse (son of Konrad Zuse)
* [http://www.ethistory.ethz.ch/rueckblicke/departemente/dinfk/weitere_seiten/angewandte_mathematik/index_DE/popupfriendly Pictures of the Z4 at the ETH Zürich (with German text)]
* {{cite web |url=http://irb.cs.tu-berlin.de/~zuse/Konrad_Zuse/en/Rechner_Z4.html |title=Textual and pictorial description of the Z4: history, instruction set and hardware features |access-date=2008-07-26 |work=Konrad Zuse's Computer |publisher=[[Technische Universität Berlin]] |url-status=dead |archive-url=https://web.archive.org/web/20080914034703/http://irb.cs.tu-berlin.de/~zuse/Konrad_Zuse/en/rechner_z4.html |archive-date=2008-09-14}}
* {{cite web |url=http://www.epemag.com/zuse/part6a.htm |title=The Z4 Computer and the Zuse Apparatebau in Berlin (1940-1945) |access-date=2008-07-26 |author-last=Zuse |author-first=Horst |author-link=Horst Zuse |work=The Life and Work of Konrad Zuse |archive-url=https://web.archive.org/web/20080601210605/http://www.epemag.com/zuse/part6a.htm |archive-date=2008-06-01}}

{{Konrad zuse computer}}

[[Category:1940s computers]]
[[Category:Electro-mechanical computers]]
[[Category:Mechanical computers]]
[[Category:One-of-a-kind computers|Z04]]
[[Category:German inventions of the Nazi period]]
[[Category:Computer-related introductions in 1945]]
[[Category:Konrad Zuse]]
[[Category:Computers designed in Germany]]
[[Category:Serial computers]]