 Zuse Z3 replica on display atDeutsches Museum inMunich | |
| Also known as | V3 (Versuchsmodell 3) |
|---|---|
| Developer | Konrad Zuse |
| Type | Programmable, fully automaticdigitalelectromechanical computer |
| Released | May 12, 1941; 84 years ago (1941-05-12) |
| Lifespan | 2 years |
| Introductory price | Costs: ca. 50,000 ℛ︁ℳ︁ |
| CPU | 2,600relays @ 5–10Hz |
| Memory | 64 words with a length of 22 bits |
| Removable storage | Punched celluloid tape[1] |
| Display | Row of lamps to show results[2] |
| Input | Terminal, with a special keyboard for input[2] |
| Power | Around 4,000watts[1] |
| Weight | Around 1 tonne (2,200 lb)[1] |
| Predecessor | Z2 |
| Successor | Z4 |
TheZ3 was a Germanelectromechanical computer designed byKonrad Zuse in 1938, and completed in 1941. It was the world's first workingprogrammable, fully automaticdigital computer.[3] The Z3 was built with 2,600relays, implementing a 22-bitword length that operated at aclock frequency of about 5–10 Hz.[1] Program code was stored on punchedfilm. Initial values were entered manually.[4][5][6]: 32–37
The Z3 was completed inBerlin in 1941. It was not considered vital, so it was never put into everyday operation.[4][5][7][6]: 30, 38–39 [a] Based on the work of the Germanaerodynamics engineerHans Georg Küssner (known for theKüssner effect), a "Program to Compute a Complex Matrix"[b] was written and used to solvewing flutter problems. Zuse asked the German government for funding to replace the relays with fully electronic switches, but funding was denied duringWorld War II since such development was deemed "not war-important".[11]: 148
The original Z3 was destroyed on 21 December 1943 during anAllied 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'sV-weapons.[12] A fully functioning replica was built in 1961 by Zuse's company, ZuseKG, which is now on permanent display atDeutsches Museum inMunich.[6]: 30
The Z3 was demonstrated in 1998 to be, in principle,Turing-complete.[13] However, because it lackedconditional branching, the Z3 only satisfies 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.[14][15][16][17]
Zuse designed theZ1 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 theTechnische Hochschule in Charlottenburg (nowTechnische Universität Berlin) in 1937 he worked on the implementation of Boolean operations and (in today's terminology)flip-flops on the basis ofvacuum tubes. 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.[2] In that year when presenting the plan for a computer with 2,000 electron tubes, Zuse and Schreyer, who was an assistant atWilhelm Stäblein's [de] Telecommunication Institute atTechnische Universität Berlin, were discouraged by members of the institute who knew about the problems with electron tube technology.[10]: 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 thecomponents have to be developed."[10]: 102 In 1940, Zuse and Schreyer managed to arrange a meeting at theOberkommando 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.[10]: 115
Zuse decided to implement the next design based on relays. The realization of theZ2 was helped financially byKurt Pannke, who manufactured small calculating machines. The Z2 was completed and presented to an audience of theDeutsche 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.[2]
In 1941, improving on the basic Z2 machine, he built the Z3 in a highly secret project of the German government.[18]Joseph Jennissen (1905–1977),[19] member of the "Research-Leadership" (Forschungsführung) in theReich Air Ministry[20] acted as a government supervisor for orders of the ministry to Zuse's companyZUSE Apparatebau.[21] A further intermediary between Zuse and the Reich Air Ministry was the aerodynamicistHerbert A. Wagner.[22]
The Z3 was completed in 1941 and was faster and far more reliable than the Z1 and Z2. The Z3floating-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.[23]: 7
On 12 May 1941, the Z3 was presented to an audience of scientists including the professors Alfred Teichmann and Curt Schmieden[24] of theDeutsche Versuchsanstalt für Luftfahrt ("German Laboratory for Aviation") inBerlin,[25] today known as theGerman Aerospace Center inCologne.[26]
Zuse moved on to theZ4 design, which he completed in a bunker in theHarz mountains, alongsideWernher von Braun's ballistic missile development. When World War II ended, Zuse retreated toHinterstein in the Alps with the Z4, where he remained for several years.[27]
The Z3 operated as astack 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.[23]: 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.[23]: 8
It was possible to construct loops on the Z3, but there was noconditional branch instruction. Nevertheless, the Z3 wasTuring-complete – how to implement a universalTuring machine on the Z3 was shown in 1998 byRaúl 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 ofspeculative 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."[13]
This seeming limitation belies the fact that the Z3 provided apracticalinstruction 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 acivil engineer.[28]
The success of Zuse's Z3 is often attributed to its use of the simple binary system.[6]: 21 This was invented roughly three centuries earlier byGottfried Leibniz;Boole later used it to develop hisBoolean algebra. Zuse was inspired byHilbert's andAckermann's book on elementary mathematical logicPrinciples of Mathematical Logic.[10]: 113, 152 In 1937,Claude Shannonintroduced the idea of mapping Boolean algebra onto electronic relays in a seminal work ondigital circuit design. Zuse, however, did not know of Shannon's work and developed the groundwork independently[11]: 149 for his first computerZ1, 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[29] in 1942, but it was lost at the end of the war.
Ananalog computer was built by the rocket scientistHelmut Hölzer in 1942 at thePeenemünde Army Research Center to simulate[30][31][32]V-2 rocket trajectories.[33][34]
TheColossus (1943),[35][36] built byTommy Flowers, and theAtanasoff–Berry computer (1942) usedthermionic valves (vacuum tubes) and binary representation of numbers. Programming was by means of re-plugging patch panels and setting switches.[citation needed]
TheENIAC computer, completed after the war, usedvacuum tubes to implement switches and used decimal representation for numbers. Until 1948 programming was, as with Colossus, by patch leads and switches.[37][38]
TheManchester Baby of 1948 along with theManchester Mark 1 andEDSAC both of 1949 were the world's earliest working computers that stored program instructions and data in the same space. In this they implemented thestored-program concept which is frequently (but erroneously) attributed toa 1945 paper byJohn von Neumann and colleagues.[39][40] Von Neumann is said to have given due credit toAlan Turing,[35][41] and the concept had actually been mentioned earlier by Konrad Zuse himself, in a 1936 patent application (that was rejected).[42][43] Konrad Zuse himself remembered in his memoirs: "During the war it would have barely been possible to build efficient stored program devices anyway."[44]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."[45][46]
A modern reconstruction directed byRaúl Rojas andHorst Zuse started in 1997 and finished in 2003. It is now in the Konrad Zuse Museum in Hünfeld, Germany.[47][48] Memory was halved to 32 words. Power consumption is about 400 W, and weight is about 30 kilograms (66 lb).[49]
In 2008, Horst Zuse started a reconstruction of the Z3 by himself.[50] It was presented in 2010 in the Konrad Zuse Museum in Hünfeld.[51][52]
{{cite book}}: CS1 maint: DOI inactive as of July 2025 (link) (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" bySpringer Vieweg, but abandoned when a lot of the content was found to have been plagiarized from other sources including Wikipedia.[1][2][3])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.
From various sides Konrad Zuse was awarded with the title "Inventor of the computer".
The Konrad-Zuse-Zentrum für Informationstechnik Berlin (ZIB), founded in 1986, is a working memorial to the German inventor of the computer.
he [Zuse] built the world's first computer in Berlin
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.
{{cite book}}: CS1 maint: ignored ISBN errors (link)Während des Krieges wäre es freilich ohnehin kaum möglich gewesen, leistungsfähige Geräte mit Speicherprogrammen zu bauen.(NB. AnEnglish translation exists.)
[Zuses] erst Jahre später publizierten visionären Ideen (Lebendige Rechenpläne) zielten in die richtige praktische Richtung, wurden von ihm aber nie verwirklicht.[[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.]
