Editing Z3 (computer) (section)

== 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"/>