View source for Z3 (computer)

{{Short description|First working programmable, fully automatic digital computer}}
{{Other uses|Z3 (disambiguation)}}
{{Use dmy dates|date=July 2022|cs1-dates=y}}
{{Use list-defined references|date=July 2022}}
{{Infobox information appliance
| name         = Z3
| title        =
| aka          = V3 (Versuchsmodell 3)
| logo         =
| image        = Z3 Deutsches Museum.JPG
| caption      = Zuse Z3 replica on display at [[Deutsches Museum]] in [[Munich]]
| developer    = [[Konrad Zuse]]
| manufacturer =
| family       =
| type         = [[Computer programming|Programmable]], fully automatic [[digital computer|digital]] [[electromechanical computer]]
| generation   =
| releasedate  = {{Start date and age|1941|05|12}}
| lifespan     = 2 years
| price        = Costs: ca. {{Reichsmark|50,000|1941|link=yes}}
| discontinued =
| unitssold    =
| unitsshipped =
| media        =
| os           =
| power        = Around 4,000 [[watt]]s<ref name="Morelli_2001"/>
| soc          =
| cpu          = 2,600 [[relay]]s
| CPUspeed     = 5–10 [[Hertz|Hz]]
| memory       = 64 words with a length of 22 bits
| storage      =
| memory card  = Punched celluloid tape<ref name="Morelli_2001"/>
| display      = Row of lamps to show results<ref name="Lippe_2007"/>
| graphics     =
| sound        =
| input        = Terminal, with a special keyboard for input<ref name="Lippe_2007"/>
| controllers  =
| camera       =
| touchpad     =
| connectivity =
| platform     =
| service      =
| dimensions   =
| weight       = Around {{convert|1|t|lb}}<ref name="Morelli_2001"/>
| topgame      =
| compatibility=
| predecessor  = [[Z2 (computer)|Z2]]
| successor    = [[Z4 (computer)|Z4]]
| related      =
| website      =
}}
The '''Z3''' was a German [[electromechanical computer]] designed by [[Konrad Zuse]] in 1938, and completed in 1941. It was the world's first working [[Computer programming|programmable]], fully automatic [[digital computer]].<ref name="NYT_1994"/> The Z3 was built with 2,600 [[relay]]s, implementing a 22-[[bit]] [[Word (data type)|word]] length that operated at a [[clock frequency]] of about 5–10&nbsp;[[Hertz|Hz]].<ref name="Morelli_2001"/> Program code was stored on punched [[celluloid|film]]. Initial values were entered manually.<ref name="Weiss_1996"/><ref name="Borchers_2016"/><ref name="Ceruzzi_1983"/>{{rp|pages=32–37}}

The Z3 was completed in [[Berlin]] in 1941. It was not considered vital, so it was never put into everyday operation.<ref name="Weiss_1996"/><ref name="Borchers_2016"/><ref name="Zuse_2013"/><ref name="Ceruzzi_1983"/>{{rp|pages=30, 38–39}}{{efn|1=It could solve problems like systems of linear equations and their determinants, quadratic equations and Eigenvalues (for [[wing flutter]]).<ref name="Slater_1989"/><ref name="Schindler_1990"/>}} Based on the work of the German [[aerodynamics]] engineer [[Hans Georg Küssner]] (known for the [[Küssner effect]]), a "Program to Compute a Complex Matrix"{{efn|1={{langx|de|Programm für die Berechnung einer komplexen Matrix}}<ref name="Hellige_2004"/>}} was written and used to solve [[wing flutter]] problems. Zuse asked the German government for funding to replace the relays with fully electronic switches, but funding was denied during [[World War II]] since such development was deemed "not war-important".<ref name="Hohn_1998"/>{{rp|page=148}}

The original Z3 was destroyed on 21 December 1943 during an [[Bombing of Berlin during World War II|Allied bombardment of Berlin]]. That Z3 was originally called V3 (''Versuchsmodell 3'' or Experimental Model 3) but was renamed so that it would not be confused with Germany's [[V-weapons]].<ref name="CMLI"/> A fully functioning replica was built in 1961 by Zuse's company, Zuse [[Kommanditgesellschaft|KG]], which is now on permanent display at [[Deutsches Museum]] in [[Munich]].<ref name="Ceruzzi_1983"/>{{rp|page=30}}

The Z3 was demonstrated in 1998 to be, in principle, [[Turing-complete]].<ref name="Rojas_1997_Universal"/> However, because it lacked [[conditional branching]], the Z3 only meets this definition by speculatively computing all possible outcomes of a calculation.

Thanks to this machine and its predecessors, [[Konrad Zuse]] has often been suggested as the inventor of the computer.<ref name="RTD"/><ref name="GermanWay"/><ref name="Leszczynski_2010"/><ref name="Bellis_2017"/>

== Design and development ==
[[File:Elektromagnetischerspeicher zuse relais.jpg|thumb|Electromagnetic memory (relays) included in the Z3, [[Z5 (computer)|Z5]] and [[Z11 (computer)|Z11]]]]
Zuse designed the [[Z1 (computer)|Z1]] in 1935 to 1936 and built it from 1936 to 1938. The Z1 was wholly mechanical and only worked for a few minutes at a time at most. [[Helmut Schreyer]] advised Zuse to use a different technology. As a doctoral student at the [[Technische Hochschule]] in Charlottenburg (now [[Technische Universität Berlin]]) in 1937 he worked on the implementation of Boolean operations and (in today's terminology) [[flip-flop (electronics)|flip-flops]] on the basis of [[vacuum tube]]s. In 1938, Schreyer demonstrated a circuit on this basis to a small audience, and explained his vision of an electronic computing machine – but since the largest operational electronic devices contained far fewer tubes this was considered practically infeasible.<ref name="Lippe_2007"/> In that year when presenting the plan for a computer with 2,000 electron tubes, Zuse and Schreyer, who was an assistant at {{ill|Wilhelm Stäblein|lt=Wilhelm Stäblein's|de}} Telecommunication Institute at [[Technische Universität Berlin]], were discouraged by members of the institute who knew about the problems with electron tube technology.<ref name="Hellige_2004"/>{{rp|pages=113, 152}} Zuse later recalled: "They smiled at us in 1939, when we wanted to build electronic machines ... We said: The electronic machine is great, but first the [[Electronic component|components]] have to be developed."<ref name="Hellige_2004"/>{{rp|page=102}} In 1940, Zuse and Schreyer managed to arrange a meeting at the [[Oberkommando der Wehrmacht]] (OKW) to discuss a potential project for developing an electronic computer, but when they estimated a duration of two or three years, the proposal was rejected.<ref name="Hellige_2004"/>{{rp|page=115}}

Zuse decided to implement the next design based on relays. The realization of the [[Z2 (computer)|Z2]] was helped financially by [[Kurt Pannke]], who manufactured small calculating machines. The Z2 was completed and presented to an audience of the {{lang|de|Deutsche Versuchsanstalt für Luftfahrt}} ("German Laboratory for Aviation") in 1940 in Berlin-Adlershof. Zuse was lucky – this presentation was one of the few instances where the Z2 actually worked and could convince the DVL to partly finance the next design.<ref name="Lippe_2007"/>

In 1941, improving on the basic Z2 machine, he built the Z3 in a highly secret project of the German government.<ref name="Parsons-Oja_2007"/> [[Joseph Jennissen]] (1905–1977),<ref name="Kauther-Wirtz_2013"/> member of the "Research-Leadership" (''Forschungsführung'') in the [[Air Ministry (Germany)|Reich Air Ministry]]<ref name="Maier_2007"/> acted as a government supervisor for orders of the ministry to Zuse's company ''ZUSE Apparatebau''.<ref name="ZIB_Chrono"/> A further intermediary between Zuse and the Reich Air Ministry was the aerodynamicist [[Herbert A. Wagner]].<ref name="Bruderer"/>

[[File: Zuse archive Z3.jpg|thumb|Drawing of the Z3 computer from Zuse's 1941 patent]]
The Z3 was completed in 1941 and was faster and far more reliable than the Z1 and Z2. The Z3 [[floating-point arithmetic]] was improved over that of the Z1 in that it implemented exception handling "using just a few relays", the exceptional values (plus infinity, minus infinity and undefined) could be generated and passed through operations. It further added a square root instruction. 

The Z3, like its predecessors, stored its program on an external punched tape, thus no rewiring was necessary to change programs. However, it did not have conditional branching found in later universal computers.<ref name="Rojas_1997_Legacy"/>{{rp|page=7}}

On 12 May 1941, the Z3 was presented to an audience of scientists including the professors Alfred Teichmann and Curt Schmieden<ref name="DHM_2013"/> of the {{lang|de|Deutsche Versuchsanstalt für Luftfahrt}} ("German Laboratory for Aviation") in [[Berlin]],<ref name="parTU_2009"/> today known as the [[German Aerospace Center]] in [[Cologne]].<ref name="DLR"/>

Zuse moved on to the [[Z4 (computer)|Z4]] design, which he completed in a bunker in the [[Harz]] mountains, alongside [[Wernher von Braun]]'s ballistic missile development. When World War II ended, Zuse retreated to [[Hinterstein]] in the Alps with the Z4, where he remained for several years.<ref name="Campbell-Kelly_1995"/>

== Instruction set ==
The Z3 operated as a [[stack machine]] with a stack of two registers, R1 and R2.  The first load operation in a program would load the contents of a memory location into R1; the next load operation would load the contents of a memory location into R2.  Arithmetic instructions would operate on the contents of R1 and R2, leaving the result in R1, and clearing R2; the next load operation would load into R2.  A store operation would store the contents of R1 into a memory location, and clear R1; the next load operation would load the contents of a memory location into R1.<ref name="Rojas_1997_Legacy"/>{{rp|page=8}}

A read keyboard operation would read a number from the keyboard into R1 and clear R2.  A display instruction would display the contents of R1 and clear R2; the next load instruction would load into R2.<ref name="Rojas_1997_Legacy"/>{{rp|page=8}}

== Z3 as a universal Turing machine ==
It was possible to construct loops on the Z3, but there was no [[conditional branch]] instruction. Nevertheless, the Z3 was [[Turing-complete]] – how to implement a universal [[Turing machine]] on the Z3 was shown in 1998 by [[Raúl Rojas]]. He proposed that the tape program would have to be long enough to execute every possible path through both sides of every branch. It would compute all possible answers, but the unneeded results would be canceled out (a kind of [[speculative execution]]). Rojas concludes, "We can therefore say that, from an abstract theoretical perspective, the computing model of the Z3 is equivalent to the computing model of today's computers. From a practical perspective, and in the way the Z3 was really programmed, it was not equivalent to modern computers."<ref name="Rojas_1997_Universal"/>

This seeming limitation belies the fact that the Z3 provided a ''practical'' [[instruction set]] for the typical engineering applications of the 1940s.  Mindful of the existing hardware restrictions, Zuse's main goal at the time was to have a workable device to facilitate his work as a [[civil engineer]].<ref name="Zuse_1987"/>

== Relation to other work ==
The success of Zuse's Z3 is often attributed to its use of the simple binary system.<ref name="Ceruzzi_1983"/>{{rp|page=21}} This was invented roughly three centuries earlier by [[Gottfried Leibniz]]; [[Boole]] later used it to develop his [[Boolean algebra (logic)|Boolean algebra]]. Zuse was inspired by [[David Hilbert|Hilbert]]'s and [[Wilhelm Ackermann|Ackermann]]'s book on elementary mathematical logic ''[[Principles of Mathematical Logic]]''.<ref name="Hellige_2004"/>{{rp|pages=113, 152}} In 1937, [[Claude Shannon]] [[A Symbolic Analysis of Relay and Switching Circuits|introduced]] the idea of mapping Boolean algebra onto electronic relays in a seminal work on [[digital circuit]] design. Zuse, however, did not know of Shannon's work and developed the groundwork independently<ref name="Hohn_1998"/>{{rp|page=149}} for his first computer [[Z1 (computer)|Z1]], which he designed and built from 1935 to 1938.

Zuse's coworker Helmut Schreyer built an electronic digital experimental model of a computer using 100 vacuum tubes<ref name="Schreyer"/> in 1942, but it was lost at the end of the war.

An [[analog computer]] was built by the rocket scientist [[Helmut Hölzer]] in 1942 at the [[Peenemünde Army Research Center]] to simulate<ref name="Hirschler"/><ref name="Neufeld_2013"/><ref name="Ulmann_2013"/> [[V-2 rocket]] trajectories.<ref name="Neufeld_1995"/><ref name="Tomayko_1985"/>

The [[Colossus computer|Colossus]] (1943),<ref name="Randell_1972"/><ref name="Copeland_2006"/> built by  [[Tommy Flowers]], and the [[Atanasoff–Berry computer]] (1942) used [[Thermionic valve|thermionic valves (vacuum tubes)]] and binary representation of numbers. Programming was by means of re-plugging patch panels and setting switches.{{Citation needed|date=May 2021}}

The [[ENIAC]] computer, completed after the war, used [[vacuum tubes]] to implement switches and used decimal representation for numbers. Until 1948 programming was, as with Colossus, by patch leads and switches.<ref name="Haigh_2016"/><ref name="Cruz_2013"/>

The [[Manchester Baby]] of 1948 along with the [[Manchester Mark 1]] and [[EDSAC]] both of 1949 were the world's earliest working computers that stored program instructions and data in the same space. In this they implemented the [[Von Neumann architecture#Development of the stored-program concept|stored-program concept]] which is frequently (but erroneously) attributed to [[First Draft of a Report on the EDVAC|a 1945 paper]] by [[John von Neumann]] and colleagues.<ref name="Neumann_1945"/><ref name="EB"/> Von Neumann is said to have given due credit to [[Alan Turing]],<ref name="Randell_1972"/><ref name="Copeland_2000"/> and the concept had actually been mentioned earlier by Konrad Zuse himself, in a 1936 patent application (that was rejected).<ref name="Williams-Kilburn_1948"/><ref name="Faber_2000"/> Konrad Zuse himself remembered in his memoirs: "During the war it would have barely been possible to build efficient stored program devices anyway."<ref name="Zuse_2010"/>  [[Friedrich L. Bauer]] later wrote: "His visionary ideas (live programs) which were only to be published years afterwards aimed at the right practical direction but were never implemented by him."<ref name="Bauer_1998"/><ref name="Zuse_2006"/>

== Specifications ==
* Average calculation speed: addition – 0.8 seconds, multiplication – 3 seconds<ref name="Morelli_2001"/>
* Arithmetic unit: Binary [[floating-point]], 22-bit, add, subtract, multiply, divide, square root<ref name="Morelli_2001"/>
* Data memory: 64 22-bit words<ref name="Morelli_2001"/>
* Program memory: Punched celluloid tape<ref name="Morelli_2001"/>
* Input: Decimal floating-point numbers<ref name="Morelli_2001"/>
* Output: Decimal floating-point numbers<ref name="Morelli_2001"/>
* Input and Output was facilitated by a terminal, with a special keyboard for input and a row of lamps to show results<ref name="Lippe_2007"/>
* Elements: Around 2,000 relays (1,400 for the memory)<ref name="Lippe_2007"/>
* Frequency: 5–10 hertz<ref name="Morelli_2001"/>
* Power consumption: Around 4,000&nbsp;[[watt]]s<ref name="Morelli_2001"/>
* Weight: Around {{convert|1|t|lb}}<ref name="Morelli_2001"/>

== Modern reconstructions ==
[[File:Finder Relais Zuse Z3 b.jpg|thumb|Z3 reconstruction in 2010 by Horst Zuse]]
A modern reconstruction directed by [[Raúl Rojas]] and [[Horst Zuse]] started in 1997 and finished in 2003. It is now in the Konrad Zuse Museum in Hünfeld, Germany.<ref name="Rojas_DCIS"/><ref name="ZIB"/> Memory was halved to 32 words. Power consumption is about 400&nbsp;W, and weight is about {{Convert|30|kg|lb}}.<ref name="Zuse_2001"/>

In 2008, Horst Zuse started a reconstruction of the Z3 by himself.<ref name="Zuse_2013_IFIP"/> It was presented in 2010 in the Konrad Zuse Museum in Hünfeld.<ref name="Zwernemann-Blech_2010"/><ref name="Zuse_2018"/>

==See also==
* [[History of computing hardware]]
* [[Reverse Polish notation]] (RPN)

== Notes ==
{{notelist}}

== References ==
{{reflist|refs=
<ref name="Rojas_1997_Legacy">{{cite journal |title=Konrad Zuse's Legacy: The Architecture of the Z1 and Z3 |author-last=Rojas |author-first=Raúl |author-link=Raúl Rojas |journal=[[IEEE Annals of the History of Computing]] |volume=19 |number=2 |date=April–June 1997 |pages=5–16 [7–8] |doi=10.1109/85.586067 |url=http://ed-thelen.org/comp-hist/Zuse_Z1_and_Z3.pdf |access-date=2022-07-03 |url-status=live |archive-url=https://web.archive.org/web/20220703082408/http://ed-thelen.org/comp-hist/Zuse_Z1_and_Z3.pdf |archive-date=2022-07-03}} (12 pages)</ref>
<ref name="Rojas_1997_Universal">{{cite journal |title=How to Make Zuse's Z3 a Universal Computer |author-last=Rojas |author-first=Raúl |author-link=Raúl Rojas |date=1997-09-05 |publication-date=July–September 1998 |journal=[[IEEE Annals of the History of Computing]] |volume=20 |issue=3 |doi=10.1109/85.707574 |pages=51–54 |url=http://www.inf.fu-berlin.de/inst/ag-ki/rojas_home/documents/1997/Universal_Computer.pdf |access-date=2022-07-02 |url-status=live |archive-url=https://web.archive.org/web/20211209133441/http://www.inf.fu-berlin.de/inst/ag-ki/rojas_home/documents/1997/Universal_Computer.pdf |archive-date=2021-12-09}} (8 pages)</ref>
<ref name="Randell_1972">{{cite conference |title=On Alan Turing and the Origins of Digital Computers |author-last=Randell |author-first=Brian |author-link=Brian Randell |editor-last1=Meltzer |editor-first1=Bernard |editor-link1=Bernard Meltzer (computer scientist) |editor-last2=Michie |editor-first2=Donald |editor-link2=Donald Michie |place=Edinburgh|publisher=[[Edinburgh University Press]] |conference=Seventh Annual Machine Intelligence Workshop |series=Machine Intelligence |volume=7 |date=1972 |isbn=0-85224-234-4 |url=https://archive.computerhistory.org/resources/access/text/2016/06/102724643-05-01-acc.pdf}}</ref>
<ref name="Copeland_2000">{{cite encyclopedia |title=The Modern History of Computing |author-first=Brian Jack |author-last=Copeland |author-link=Brian Jack Copeland |encyclopedia=The Stanford Encyclopedia of Philosophy |date=June 9, 2006 |url=https://plato.stanford.edu/archives/win2020/entries/computing-history/ |access-date=2023-09-07}}</ref>
<ref name="Copeland_2006">{{cite book |title=Colossus: The Secrets of Bletchley Park's Codebreaking Computers |editor-first=Brian Jack |editor-last=Copeland |editor-link=Brian Jack Copeland |date=2006 |publisher=[[Oxford University Press]] |isbn=978-0-19-284055-4}}</ref>
<ref name="Hellige_2004">{{cite book |editor-first=Hans Dieter |editor-last=Hellige |title=Geschichten der Informatik. Visionen, Paradigmen, Leitmotive |language=de |publisher=Springer |location=Berlin |date=2004 |isbn=978-3-540-00217-8 |pages=102, 113, 115, 152 |quote-page=102 |quote=Man hat 1939 über uns gelächelt, als wir elektronische Geräte bauen wollten. […] Wir sagten uns damals: Die elektronische Maschine ist wunderbar, aber erst müssen ihre Bauelemente entwickelt werden.}}</ref>
<ref name="Lippe_2007">{{cite book |title=Die Geschichte der Rechenautomaten |language=de |trans-title=The history of calculating machines |chapter=Kapitel 14 – Die ersten programmierbaren Rechner |trans-chapter=The first programmable computers |author-last=Lippe |author-first=Wolfram-Manfred |author-link=:d:Q102176548 |date=2010|orig-date=2007 |doi=10.1007/978-3-642-36193-7_6 |doi-broken-date=2 January 2025 |url=http://cs.uni-muenster.de/Professoren/Lippe/lehre/skripte/geschichte/index.html |chapter-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}} [https://web.archive.org/web/20131213213039/http://cs.uni-muenster.de/Professoren/Lippe/lehre/skripte/geschichte/index.html] (NB. This script was published in December 2013 in a three-volume book series "Geschichte der Rechenautomaten": "Von der Himmelsscheibe von Nebra bis zu den ersten Rechenmaschinen", "Von mechanischen Chiffriergeräten bis zu den ersten programmierbaren Rechnern" and "Von der Entwicklung der Hardware bis zum WWW" by [[Springer Vieweg]], but abandoned when a lot of the content was found to have been plagiarized from other sources including Wikipedia.[https://web.archive.org/web/20220918074721/https://www.faz.net/aktuell/feuilleton/medien/ein-plagiatsfall-bei-springer-vieweg-12936387.html][https://web.archive.org/web/20220918074738/https://www-mailman.uni-regensburg.de/pipermail/oldenburg/2014-June/000739.html][https://web.archive.org/web/20220918075014/https://plagiatsgutachten.com/blog/uni-muenster-ehemaliger-informatik-professor-soll-wikipedia-plagiiert-haben/])</ref>
<ref name="Ceruzzi_1983">{{cite book |author-last=Ceruzzi |author-first=Paul E. |author-link=Paul E. Ceruzzi |title=Reckoners: The Prehistory of The Digital Computer, From Relays to the Stored Program Concept, 1935–1945 |publisher=[[Greenwood Press]] |date=1983 |chapter=2. Computers in Germany |isbn=0-313-23382-9 |pages=21, 30, 32–39 |chapter-url=https://ed-thelen.org/comp-hist/Reckoners-ch-2.html |access-date=2018-11-03}}</ref>
<ref name="Slater_1989">{{cite book |title=Portraits in Silicon |author-last=Slater |author-first=Robert |author-link=Robert Slater |date=1989 |publisher=[[MIT Press]] |isbn=978-0-26269131-4 |pages=46–47 |url=https://books.google.com/books?id=aWTtMyYmKhUC&pg=PA46}}</ref>
<ref name="Schindler_1990">{{cite book |title=Computer-aided software design: build quality software with CASE |language=en |author-last=Schindler |author-first=Max J. |date=1990 |publisher=Wiley |isbn=978-0-47150650-8 |page=419 |url=https://books.google.com/books?id=uxWzAAAAIAAJ&q=determinants}}</ref>
<ref name="Hohn_1998">{{cite book |author-first=Hans-Willy |author-last=Hohn |author-link=:de:Hans-Willy Hohn |title=Kognitive Strukturen und Steuerungsprobleme der Forschung. Kernphysik und Informatik im Vergleich |date=1998 |publisher=Schriften des Max-Planck-Instituts für Gesellschaftsforschung Köln |language=de |isbn=978-3-593-36102-4 |pages=148–149}}</ref>
<ref name="Weiss_1996">{{cite journal |title=Konrad Zuse Obituary |author-last=Weiss |author-first=Eric A. |date=Summer 1996 |journal=[[IEEE Annals of the History of Computing]] |language=en-US |volume=18 |issue=2 |pages=3–4 |doi=10.1109/mahc.1996.489747 |issn=1058-6180}}</ref>
<ref name="Borchers_2016">{{cite web |title=Vor 75 Jahren: Computer Z3 wird vorgeführt |language=de-DE |trans-title=75 years ago: Computer Z3 is demonstrated |author-last=Borchers |author-first=Detlef Henning |author-link=:de:Detlef Henning Borchers |date=2016-05-12 |website=[[heise online]] |url=https://www.heise.de/newsticker/meldung/Vor-75-Jahren-Computer-Z3-wird-vorgefuehrt-3205261.html |access-date=2018-05-13}}</ref>
<ref name="Zuse_2010">{{anchor|Zuse-2010}}{{cite book |title=Der Computer – Mein Lebenswerk |language=de |author-first=Konrad |author-last=Zuse |author-link=Konrad Zuse |location=Berlin, Germany |edition=5 |isbn=978-3-64212095-4 |publisher=Springer |date=2010 |page=78 |quote=Während des Krieges wäre es freilich ohnehin kaum möglich gewesen, leistungsfähige Geräte mit Speicherprogrammen zu bauen.}} (NB. An [[#Zuse-2013|English translation]] exists.)</ref>
<ref name="Zuse_2013">{{anchor|Zuse-2013}}{{cite book |title=The Computer – My Life |language=en |author-last=Zuse |author-first=Konrad |author-link=Konrad Zuse |date=2013 |publisher=[[Springer Science & Business Media]] |isbn=978-3-66202931-2 |page=64 |url=https://books.google.com/books?id=edWoCAAAQBAJ&pg=PA64}} (NB. This is a translation of the original German title {{lang|de|[[#Zuse-2010|Der Computer – Mein Lebenswerk]]}}.)</ref>
<ref name="Morelli_2001">{{cite book |title=Dalle calcolatrici ai computer degli anni Cinquanta |language=it |author-last=Morelli |author-first=Marcello |date=2001 |publisher=FrancoAngeli |isbn=978-8-84642879-0 |page=177 |url=https://books.google.com/books?id=p5GszzXR550C&pg=PA177 |access-date=2014-08-05}}</ref>
<ref name="Williams-Kilburn_1948">{{cite journal |title=Electronic Digital Computers |author-last1=Williams |author-first1=Frederic Calland |author-link1=Frederic Calland Williams |author-last2=Kilburn |author-first2=Tom |author-link2=Tom Kilburn |journal=[[Nature (journal)|Nature]] |date=1948-09-25 |volume=162 |issue=4117 |bibcode=1948Natur.162..487W |s2cid=4110351 |page=487 |doi=10.1038/162487a0 |doi-access=free }}</ref>
<ref name="Faber_2000">{{citation |title=Konrad Zuses Bemühungen um die Patentanmeldung der Z3 |language=de |author-first=Susanne |author-last=Faber |date=2000}}</ref>
<ref name="Ulmann_2013">{{cite book |title=Analog Computing |language=en |author-last=Ulmann |author-first=Bernd |author-link=:de:Bernd Ulmann |date=2013
|publisher=[[Walter de Gruyter]] |isbn=978-3-48675518-3 |page=38 |url=https://books.google.com/books?id=y1DpBQAAQBAJ&q=Hoelzer+1941&pg=PA38}}</ref>
<ref name="Maier_2007">{{cite book |title=Forschung als Waffe |language=de |author-first=Helmut |author-last=Maier |author-link=:de:Helmut Maier (Wissenschaftshistoriker) |publisher={{ill|Wallstein Verlag|de}} |date=2007 |isbn=978-3-8353-0109-2 |page=847}}</ref>
<ref name="DHM_2013">{{cite web |title=An einem 12. Mai |language=de |publisher=[[Deutsches Historisches Museum]] (German Historical Museum) |url=http://www.dhm.de/gaeste/luise/tagesfakten/tf05/0512.htm |url-status=dead |archive-url=https://web.archive.org/web/20130530040033/http://www.dhm.de/gaeste/luise/tagesfakten/tf05/0512.htm |archive-date=2013-05-30}}</ref>
<ref name="Tomayko_1985">{{cite journal |title=Helmut Hoelzer's Fully Electronic Analog Computer |date=1985 |author-last=Tomayko |author-first=James E. |s2cid=15986944 |journal=[[IEEE Annals of the History of Computing]] |volume=7 |issue=3 |doi=10.1109/MAHC.1985.10025 |pages=227–240}}</ref>
<ref name="Neufeld_1995">{{cite book |title=The Rocket and the Reich: Peenemünde and the Coming of the Ballistic Missile Era |author-last=Neufeld |author-first=Michael J. |author-link=Michael J. Neufeld |date=1995 |publication-place=New York |publisher=[[The Free Press (publisher)|The Free Press]], [[Simon & Schuster Inc.]] / [[The Smithsonian Institution]] |isbn=0-02-922895-6 |lccn=94-30088 |page=106}}<!-- (368? pages) --></ref>
<ref name="Neufeld_2013">{{cite book |title=The Rocket and the Reich: Peenemünde and the Coming of the Ballistic Missile Era |language=en |author-last=Neufeld |author-first=Michael J. |author-link=Michael J. Neufeld |date=2013 |edition=2 |version=3.1 |publisher=[[Smithsonian Books]] / [[The Smithsonian Institution]] |publication-place=Washington, DC |isbn=((987-1-58834-467-0))<!-- this is the ISBN actually printed in the book --> |page=138 |url=https://books.google.com/books?id=L6BfBgAAQBAJ&pg=PT138}}<!-- (400? pages) --></ref>
<ref name="NYT_1994">{{cite news |url=https://www.nytimes.com/1994/04/20/news/20iht-zuse.html |title=A Computer Pioneer Rediscovered, 50 Years On |date=1994-04-20 |newspaper=[[The New York Times]] |url-status=dead |archive-url=https://web.archive.org/web/20161104051054/http://www.nytimes.com/1994/04/20/news/20iht-zuse.html |archive-date=2016-11-04}}</ref>
<ref name="CMLI">{{cite web |url=http://www.computermuseum.li/Testpage/Z3-Computer-1939.htm |title=Z3 Computer (1938–1941) |archive-url=https://web.archive.org/web/20080617234903/http://www.computermuseum.li/Testpage/Z3-Computer-1939.htm |archive-date=2008-06-17 |website=www.computermuseum.li}}</ref>
<ref name="RTD">{{cite web |url=https://www.rtd-net.de/Zuse.html |title=Konrad Zuse Biography |website=RTD Net |quote=From various sides Konrad Zuse was awarded with the title "Inventor of the computer".}}</ref>
<ref name="GermanWay">{{cite web |url=https://www.german-way.com/notable-people/featured-bios/konrad-zuse/ |title=Konrad Zuse |website=The German Way |quote=The Konrad-Zuse-Zentrum für Informationstechnik Berlin (ZIB), founded in 1986, is a working memorial to the German inventor of the computer.}}</ref>
<ref name="Leszczynski_2010">{{cite web |url=http://www.monstersandcritics.com/tech/features/article_1566782.php/Z-like-Zuse-German-inventor-of-the-computer |title=Z like Zuse: German inventor of the computer |author-first=Ulrike |author-last=von Leszczynski |date=2010-06-27 |website=Monsters & Critics |archive-url=https://web.archive.org/web/20130522022610/http://www.monstersandcritics.com/tech/features/article_1566782.php/Z-like-Zuse-German-inventor-of-the-computer |archive-date=2013-05-22 |url-status=dead |quote=he [Zuse] built the world's first computer in Berlin}}</ref>
<ref name="Bellis_2017">{{cite web |url=https://www.thoughtco.com/konrad-zuse-modern-computer-4078237 |title=Konrad Zuse and the Invention of the Modern Computer |author-first=Mary |author-last=Bellis |date=2017-07-31 |quote=Zuse earned the semi-official title of "inventor of the modern computer" for his series of automatic calculators, which he invented to help him with his lengthy engineering calculations.}}</ref>
<ref name="Parsons-Oja_2007">[https://books.google.com/books?id=VVVVkm9G5jgC&dq=konrad+zuse%2C+nazi&pg=PA489 "New perspectives, computer concepts"], June Jamrich Parsons, Dan Oja. Cengage Learning, 2007. {{ISBN|978-1-4239-0610-0}}. Retrieved 2010-03-14.</ref>
<ref name="Kauther-Wirtz_2013">Alexander Kauther, Paul Wirtz: ''Der Einzelkämpfer Dorner''. Grin Verlag Gmbh, 2013, {{ISBN|3-656-04860-6}}</ref>
<ref name="ZIB_Chrono">{{cite web |url=http://www.zib.de/zuse/Inhalt/Texte/Chrono/60er/Html/0315/0315.html |title=1977-compilation by Zuse of people in contact to his computers from 1935 to 1945 |language=de |archive-url=https://web.archive.org/web/20110928123346/http://www.zib.de/zuse/Inhalt/Texte/Chrono/60er/Html/0315/0315.html |archive-date=2011-09-28 |url-status=dead}}</ref>
<ref name="Bruderer">{{cite web |url=https://www.research-collection.ethz.ch/bitstream/handle/20.500.11850/68647/eth-2428-01.pdf |title=Konrad Zuse und die ETH Zürich |language=de |author=Herbert Bruderer, [[ETH Zurich]] |date=2010 |publisher=ETH Zurich |access-date=2023-12-04 |doi=10.3929/ethz-a-006313025}}</ref>
<ref name="parTU_2009">{{cite web |url=http://www2.tu-berlin.de/alumni/parTU/00dez/zuse.htm |title=Technische Universität Berlin – Rechenhilfe für Ingenieure |language=de |publisher=[[Technische Universität Berlin]] |url-status=dead |archive-url=https://web.archive.org/web/20090213222711/http://www2.tu-berlin.de/alumni/parTU/00dez/zuse.htm |archive-date=2009-02-13}}</ref>
<ref name="Campbell-Kelly_1995">{{Cite web |title=Obituary: Konrad Zuse |author-last=Campbell-Kelly |author-first=Martin |author-link=Martin Campbell-Kelly |work=[[The Independent]] |date=1995-12-21 |access-date=2021-05-11 |url=https://www.independent.co.uk/news/people/obituary-konrad-zuse-1526795.html |archive-url=https://ghostarchive.org/archive/20220507/https://www.independent.co.uk/news/people/obituary-konrad-zuse-1526795.html |archive-date=2022-05-07 |url-access=subscription |url-status=live}}{{cbignore}}</ref>
<ref name="Zuse_1987">{{Cite web |url=https://history.computer.org/pioneers/zuse.html |title=My First Computer and First Thoughts About Data Processing |author-last=Zuse |author-first=Konrad |author-link=Konrad Zuse |date=1987-10-02 |website=history.computer.org |series=Computer Pioneers – Konrad Zuse |access-date=2018-05-14}} Search for ''1941''; ["Computer Design-Past, Present, Future", talk in Lund/Sweden, 1987-10-02, previously unpublished.]</ref>
<ref name="Schreyer">[https://www.nue.tu-berlin.de/menue/geschichte/historische_persoenlichkeiten/schreyer "Helmut Schreyer" at the University of Berlin]</ref>
<ref name="Hirschler">[https://query.nytimes.com/gst/fullpage.html?res=9405E5DF1531F93AA35751C0A9679C8B63 H. Otto Hirschler, 87, Aided Space Program]</ref>
<ref name="Neumann_1945">{{cite web |author-last=von Neumann |author-first=John |author-link=John von Neumann |title=First Draft of a Report on the EDVAC |date=1945 |url=http://www.virtualtravelog.net/wp/wp-content/media/2003-08-TheFirstDraft.pdf |access-date=2014-03-24 |archive-url=https://web.archive.org/web/20141016002547/http://www.virtualtravelog.net/wp/wp-content/media/2003-08-TheFirstDraft.pdf |archive-date=2014-10-16 |url-status=dead}}</ref>
<ref name="EB">{{cite encyclopedia |encyclopedia=Encyclopædia Britannica |title=Stored-program concept |url=http://www.britannica.com/EBchecked/topic/567553/stored-program-concept |access-date=2014-03-24}}</ref>
<ref name="Bauer_1998">{{cite journal |title=Wer erfand den von-Neumann-Rechner? |language=de |trans-title=Who invented the von Neumann computer? |author-last=Bauer |author-first=Friedrich Ludwig |author-link=Friedrich Ludwig Bauer |journal=[[Informatik Spektrum]] |issn=0170-6012 |publisher={{ill|Spektrum Akademischer Verlag|de}} |publication-place=Heidelberg, Germany |date=April 1998 |volume=21 |issue=2 |pages=84–88 |doi=10.1007/s002870050091 |s2cid=28380924 |quote="[Zuses] erst Jahre später publizierten visionären Ideen (Lebendige Rechenpläne) zielten in die richtige praktische Richtung, wurden von ihm aber nie verwirklicht." |trans-quote=[Zuse's] visionary ideas (Living programs) which were only to be published years afterwards aimed at the right practical direction but were never implemented by him.}}</ref>
<ref name="Zuse_2006">{{cite web |title=Anmerkungen zum John von Neumann Rechner |language=de |trans-title=Annotation on the John von Neumann computer |author-first=Horst |author-last=Zuse |author-link=Horst Zuse |date=2006 |page=9 |url=http://www.horst-zuse.homepage.t-online.de/fiff99-a-2006.pdf |access-date=2022-09-18 |url-status=live |archive-url=https://web.archive.org/web/20220311053318/https://horst-zuse.homepage.t-online.de/fiff99-a-2006.pdf |archive-date=2022-03-11}} (18 pages)</ref>
<ref name="Rojas_DCIS">{{cite web |title=Reconstruction of Konrad Zuse's Z3 Computer |author-first=Raúl |author-last=Rojas |author-link=Raúl Rojas |url=https://dcis.inf.fu-berlin.de/rojas/reconstruction-of-konrad-zuses-z3-computer/ |website=dcis.inf.fu-berlin.de}}</ref>
<ref name="ZIB">{{cite web |title=Reconstructing the calculating machine Z3 |url=http://zuse.zib.de/reconstructionZ3 |website=Konrad Zuse Internet Archive}}</ref>
<ref name="Zuse_2001">{{cite web |url=http://www.horst-zuse.homepage.t-online.de/z3-nachbau-2001.html |title=Z3-Nachbau-2001 |website=www.horst-zuse.homepage.t-online.de |language=de |trans-title=Z3 replica 2001}}</ref>
<ref name="Zuse_2013_IFIP">{{cite conference |author-last=Zuse |author-first=Horst |author-link=Horst Zuse |title=Reconstruction of Konrad Zuse's Z3 |volume=416 |date=2013 |book-title=Making the History of Computing Relevant |pages=287–296 |publisher=Springer Berlin Heidelberg |language=en |doi=10.1007/978-3-642-41650-7_26 |isbn=978-3-64241649-1 |conference=IFIP WG 9.7 International Conference, HC 2013 |series=IFIP Advances in Information and Communication Technology |doi-access=free | editor1= Arthur Tatnall | editor2=Tilly Blyth | editor3= Roger Johnson}}</ref>
<ref name="Zwernemann-Blech_2010">{{cite web |url=http://www.horst-zuse.homepage.t-online.de/horst-zuse-zuse-jahr-2010-html/english/veranstaltung.html |title=Events during Zuse Year 2010 |author-last=Zwernemann-Blech |author-first=Irene |website=www.horst-zuse.homepage.t-online.de |access-date=2018-11-03}}</ref>
<ref name="Zuse_2018">{{cite web |url=http://www.horst-zuse.homepage.t-online.de/horst-zuse-z3-html/z3-vermarktung.html |title=Z3-Präsentationen|website=www.horst-zuse.homepage.t-online.de |language=de |trans-title=Z3 – Presentations |access-date=2018-11-03}}</ref>
<ref name="DLR">{{cite web |title=Die Geschichte des DLR-Standorts Berlin-Adlershof |at=1941 |language=de |url=https://www.dlr.de/de/das-dlr/ueber-uns/geschichte-des-dlr/die-geschichte-des-dlr-standorts-berlin-adlershof |publisher=[[German Aerospace Center]]}}</ref>
<ref name="Haigh_2016">{{cite book |author-last=Haigh |author-first=Thomas |url=https://www.worldcat.org/oclc/952615433 |title=ENIAC in action: making and remaking the modern computer |date=2016 |others=Mark Priestley, Crispin Rope |isbn=978-0-262-03398-5 |location=Cambridge, Massachusetts; London|publisher=[[MIT Press]] |pages=113–114 |oclc=952615433}}</ref>
<ref name="Cruz_2013">{{cite web |author-last=Cruz |author-first=Frank |date=2013-11-09 |title=Programming the ENIAC |url=http://www.columbia.edu/cu/computinghistory/eniac.html |access-date=2016-05-16 |website=Programming the ENIAC |publisher=Columbia University}}</ref>
}}

== Further reading ==
* {{cite journal |title=The reconstruction of Konrad Zuse's Z3 |author-first1=Raúl |author-last1=Rojas |author-link1=Raúl Rojas |author-first2=Frank |author-last2=Darius |author-first3=Cüneyt |author-last3=Göktekin |author-first4=Georg |author-last4=Heyne |journal=[[IEEE Annals of the History of Computing]] |volume=27 |issue=3 |pages=23–32 |date=2005-08-22 |doi=10.1109/mahc.2005.48 |s2cid=16288658 |issn=1058-6180 |eissn=1934-1547}}
* {{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/20220625103304/http://www.cs.man.ac.uk/CCS/res/res37.htm#c |archive-date=2022-06-25}}

== External links ==
{{commons category|Zuse Z3}}
* [http://www.horst-zuse.homepage.t-online.de/Konrad_Zuse_index_english_html/rechner_z3.html Z3 page at Horst Zuse's website]
* [https://web.archive.org/web/20071210232351/http://www.epemag.com/zuse/default.htm#index The Life and Work of Konrad Zuse]
* [https://purl.umn.edu/60298 Paul E. Ceruzzi Collection on Konrad Zuse (CBI 219)]. [[Charles Babbage Institute]], University of Minnesota. Collection contains published reports, articles, product literature, and other materials.

{{Konrad zuse computer}}
{{CPU technologies}}

{{Authority control}}

{{DEFAULTSORT:Z03}}
[[Category:1940s computers]]
[[Category:Electro-mechanical computers|Z3]]
[[Category:One-of-a-kind computers]]
[[Category:German inventions of the Nazi period]]
[[Category:World War II German electronics]]
[[Category:Computer-related introductions in 1941]]
[[Category:Konrad Zuse]]
[[Category:Computers designed in Germany]]
[[Category:Serial computers]]