Editing Z1 (computer)

{{short description|Mechanical computer built by Konrad Zuse in the 1930s}}
{{use dmy dates|date=July 2022|cs1-dates=y}}
{{use list-defined references|date=July 2022}}
{{Infobox information appliance
| name         = Z1
| title        =
| aka          = V1 (Versuchsmodell 1)
| logo         =
| image        = German Museum of Technology, Berlin 2017 024.jpg
| caption      = Replica of the Z1 in the [[German Museum of Technology]] in Berlin
| developer    = [[Konrad Zuse]]
| manufacturer =
| family       =
| type         = [[Computer programming|Programmable]], binary, electrically motor-driven [[mechanical computer]]
| generation   =
| releasedate  = {{Start date and age|1938}}
| lifespan     = 5 years
| price        =
| discontinued =
| unitssold    =
| unitsshipped =
| media        = [[35 mm movie film|35-millimeter film]]
| os           =
| power        = [[Electric motor]] of a vacuum cleaner
| soc          =
| cpu          = Ca. 30,000 metal sheets
| CPUspeed     = 1&nbsp;[[Hertz|Hz]]
| memory       = ''Original:'' 16-word floating point memory<br/>
''Replica:'' 64-word floating point memory 
| storage      =
| memory card  =
| display      =
| graphics     =
| sound        =
| input        = Keyboard, [[punched tape]] reader
| controllers  =
| camera       =
| touchpad     =
| connectivity =
| platform     =
| service      =
| dimensions   =
| weight       = {{convert|1|t|lb}}
| topgame      =
| compatibility=
| predecessor  =
| successor    = [[Z2 (computer)|Z2]]
| related      =
| website      =
}}
The '''Z1'''  was a motor-driven mechanical [[computer]] designed by [[Germany|German]] inventor [[Konrad Zuse]] from 1936 to 1937, which he built in his parents' home from 1936 to 1938.<ref name="Bauler_2009"/><ref name="Zuse_1976"/> It was a binary, electrically driven, mechanical calculator, with limited programmability, reading instructions from punched celluloid film.

The “Z1” was the first freely programmable computer in the world that used [[Boolean logic]] and binary [[Floating-point arithmetic|floating-point numbers]]; however, it was unreliable in operation.<ref name="Priestley_2011"/><ref name="Rojas_2006"/>  It was completed in 1938 and financed completely by private funds. This computer was destroyed in the bombardment of Berlin in December 1943, during [[World War II]], together with all construction plans.

The Z1 was the first in a series of computers that Zuse designed. Its original name was "V1" for Versuchsmodell 1 (meaning Experimental Model 1). After WW2, it was renamed "Z1" to differentiate it from the [[V-1 flying bomb|flying bombs]] designed by [[Robert Lusser]].<ref name="Campbell-Kelly_1995"/> The [[Z2 (computer)|Z2]] and [[Z3 (computer)|Z3]] were follow-ups based on many of the same ideas as the Z1.

==Design==
[[File: Zuse Patent 907948.jpg|thumb|Diagrams from Zuse's May 1936 patent for a binary switching element using a mechanism of flat sliding rods. The Z1 was based on such elements.]]

The Z1 contained almost all the parts of a modern computer, i.e. control unit, memory, micro sequences, [[floating-point]] logic, and input-output devices. The Z1 was freely programmable via punched tape and a punched tape reader.<ref name="Rojas_1997"/> There was a clear separation between the punched tape reader, the control unit for supervising the whole machine and the execution of the instructions, the arithmetic unit, and the input and output devices.
The input tape unit read perforations in [[35 mm movie film|35-millimeter film]].<ref name="Rojas_Z1"/>

The Z1 was a 22-bit [[floating-point]] value [[Adder (electronics)|adder]] and [[subtractor]], with some control logic to make it capable of more complex operations such as multiplication (by repeated additions) and division (by repeated subtractions). The Z1's [[instruction set]] had eight instructions and it took between one and twenty-one [[cycles per instruction]].

The Z1 had a 16-word floating point memory, where each word of memory could be read from – and written to – the control unit. The mechanical memory units were unique in their design and were patented by Konrad Zuse in 1936. The machine was only capable of executing instructions while reading from the [[punched tape]] reader, so the program itself was not loaded in its entirety into internal memory in advance.

The input and output were in decimal numbers, with a decimal exponent and the units had special machinery for converting these to and from binary numbers. The input and output instructions would be read or written as floating-point numbers. The program tape was a 35&nbsp;mm film with the instructions encoded in punched holes.

==Construction==
{{Quotebox
|quote=There is a replica of this Model in the [[German Museum of Technology|Museum of Traffic and Technology]] in Berlin. Back then it didn't function well, and in that regard the replica is very reliable — it also doesn't work well.<ref name="Hellige_2004"/>
|source= -[[Konrad Zuse]]
| align = left
| width = 250px
| salign = right
}}
[[File:Zuse Z1 - Flickr - KlausNahr (3).jpg|thumb|Inside view of the Z1]]
[[File:2021-08-17 Deutsches Technikmuseum Berlin 027.jpg|thumb|Numeric input]]
[[File:2021-08-17 Deutsches Technikmuseum Berlin 029.jpg|thumb|The output of computational results]]
"Z1 was a machine weighing about 1 tonne in weight, which consisted of some 20,000 parts. It was a programmable computer, based on binary floating-point numbers and a binary switching system. It consisted completely of thin metal sheets, which Zuse and his friends produced using a jigsaw."<ref name="HC"/> "The [data] input device was a keyboard...The Z1's programs (Zuse called them Rechenpläne, computing plans) were stored on punch tapes using an 8-bit code"<ref name="HC"/>

Construction of the Z1 was privately financed. Zuse got money from his parents, his sister Lieselotte, some students of the fraternity ''AV Motiv'' (cf. [[Helmut Schreyer]]), and Kurt Pannke (a calculating machine manufacturer in Berlin) to do so.

Zuse constructed the Z1 in his parents' apartment; in fact, he was allowed to use the living room for his construction. In 1936, Zuse quit his job in airplane construction to build the Z1.

Zuse is said to have used "thin metal strips" and perhaps "metal cylinders" or glass plates to construct Z1. There were probably no commercial [[relay]]s in it (though the Z3 is said to have used a few telephone relays).
The only electrical unit was an electric motor to give the [[clock frequency]] of 1&nbsp;[[Hertz|Hz]] (cycle per second) to the machine.

'The memory was constructed from thin strips of slotted metal and small pins and proved faster, smaller, and more reliable, than relays. The Z2 used the mechanical memory of the Z1 but used relay-based arithmetic. The Z3 was experimentally built entirely of relays.
The [[Z4 (computer)|Z4]] was the first attempt at a commercial computer, reverting to the faster and more economical mechanical slotted metal strip memory, with relay processing, of the Z2, but the war interrupted the Z4 development.'<ref name="Malcolm_2000"/>

The Z1 was never very reliable in operation because of poor synchronization caused by internal and external stresses on the mechanical parts.

While various sources make various statements about exactly how Zuse's computers were constructed, a clear understanding is gradually emerging.<ref name="Hackaday_2021"/>

==Reconstruction==
[[File:Zuse Z1 Nachbau, Deutsches Technikmuseum Berlin, 1.jpg|thumb|Reconstruction of Z1]]
The original Z1 was destroyed by the [[Bombing of Berlin in World War II|Allied air raids in 1943]], but in the 1980s Zuse decided to rebuild the machine. The first sketches of the Z1 reconstruction were drawn in 1984. He constructed (with the help of two engineering students) thousands of elements of the Z1 again, and finished rebuilding the device in 1989. This replication has a 64-word memory instead of a 16-word one. The rebuilt Z1 (pictured) is displayed at the [[German Museum of Technology]] in Berlin.<ref name="Rojas_Z1"/><ref name="Rojas_2014"/>

==See also==
* [[History of computing hardware]]
* [[Analytical Engine]]
* [[Difference engine]]

==References==
{{reflist|refs=
<ref name="Rojas_1997">{{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 |doi=10.1109/85.586067 |pages=5–16 |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="HC">{{cite web |title=Konrad Zuse — the first relay computer |url=https://history-computer.com/ModernComputer/Relays/Zuse.html |url-status=dead |archive-url=https://web.archive.org/web/20150101000011/https://history-computer.com/ModernComputer/Relays/Zuse.html |archive-date=2015-01-01}}</ref>
<ref name="Bauler_2009">{{cite book |title=Origins and Foundations of Computing: In Cooperation with Heinz Nixdorf MuseumsForum |author-last=Bauer |author-first=Friedrich Ludwig |author-link=Friedrich Ludwig Bauer |date=2009-11-05 |publisher=[[Springer Science & Business Media]] |isbn=978-3-64202992-9 |language=en |pages=78– |url=https://books.google.com/books?id=y4uTaLiN-wQC&q=%22arithmetic+unit%22+1938&pg=PA78 |access-date=2022-07-10}}</ref>
<ref name="Zuse_1976">{{cite book |title=The Plankalkül |author-last=Zuse |author-first=Konrad |author-link=Konrad Zuse |date=1976 |publisher=[[Gesellschaft für Mathematik und Datenverarbeitung]] (GMD) |pages=21– |language=en |url=https://books.google.com/books?id=VN5UAAAAYAAJ&q=1938 |access-date=2022-07-10}}</ref>
<ref name="Priestley_2011">{{cite book |title=A Science of Operations: Machines, Logic and the Invention of Programming |author-first=Mark |author-last=Priestley |publisher=[[Springer-Verlag]] |date=2011 |isbn=978-1-84882-554-3}}</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 transcript 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="Campbell-Kelly_1995">{{cite news |title=Obituary: Konrad Zuse |author-first=Martin |author-last=Campbell-Kelly |author-link=Martin Campbell-Kelly |date=1995-12-21 |department=People - News |newspaper=[[The Independent]] |url=https://www.independent.co.uk/news/people/obituary--konrad-zuse-1526795.html |access-date=2022-07-10 |url-status=live |archive-url=https://web.archive.org/web/20220709224401/https://www.independent.co.uk/news/people/obituary-konrad-zuse-1526795.html |archive-date=2022-07-09}}</ref>
<ref name="Rojas_Z1">{{cite web |title=Reconstruction of the Z1 Computer |author-last=Rojas |author-first=Raúl |author-link=Raúl Rojas |website=dcis.inf.fu-berlin.de |publisher=[[Free University of Berlin]] |url=https://dcmlr.inf.fu-berlin.de/rojas/reconstruction-of-the-z1-computer/ |access-date=2022-05-10 |url-status=live |archive-url=https://web.archive.org/web/20220709224920/https://dcmlr.inf.fu-berlin.de/rojas/reconstruction-of-the-z1-computer/ |archive-date=2022-07-09}}</ref>
<ref name="Malcolm_2000">{{cite web |title=Who Made the First Computer |author-first=Chris |author-last=Malcolm |date=2000 |url=http://www.dai.ed.ac.uk/homes/cam/fcomp.shtml}}</ref>
<ref name="Rojas_2014">{{cite book |title=The Z1: Architecture and Algorithms of Konrad Zuse's First Computer |author-last=Rojas |author-first=Raúl |author-link=Raúl Rojas |date=2014-06-07 |arxiv=1406.1886}}</ref>
<ref name="Hellige_2004">{{cite book |title=Geschichten der Informatik. Visionen, Paradigmen, Leitmotive |language=de |editor-first=Hans Dieter |editor-last=Hellige |publisher=[[Springer-Verlag]] |publication-place=Berlin, Germany |date=2004 |isbn=978-3-540-00217-8 |page=36}}</ref>
<ref name="Hackaday_2021">{{cite web |title=The Other First Computer: Konrad Zuse And The Z3: Zuse's Mechanical XNOR Gate |author-first=Chris |author-last=Lott |date=2021-06-16 |website=hackaday.com |url=https://hackaday.com/2021/06/16/the-other-first-computer-konrad-zuse-and-the-z3/ |access-date=2023-10-15 |url-status=live |archive-url=https://web.archive.org/web/20231015074107/https://hackaday.com/2021/06/16/the-other-first-computer-konrad-zuse-and-the-z3/ |archive-date=2023-10-15}}</ref>
}}

==Further reading==
* {{cite book |title=The Computer – My Life |language=en |author-last=Zuse |author-first=Konrad |author-link=Konrad Zuse |date=2013-03-09 |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|Der Computer - Mein Lebenswerk}}.)
* {{cite book |title=The Design Principles of Konrad Zuse's Mechanical Computers |author-last=Rojas |author-first=Raúl |author-link=Raúl Rojas |date=2016-03-08 |arxiv=1603.02396}} (NB. Paper describes the design principles of Zuse Z1.)

==External links==
{{commons category|Zuse Z1}}
* {{cite web |title=The life and work of Konrad Zuse |author-first=Horst |author-last=Zuse |author-link=Horst Zuse |publisher=EPEmag |url=http://www.epemag.com/zuse/ |archive-url=https://web.archive.org/web/20100418164050/http://www.epemag.com/zuse/ |archive-date=2010-04-18}}
* {{cite web |title=Zuse Z1 detailed information |author-first=Horst |author-last=Zuse |author-link=Horst Zuse |url=http://www.horst-zuse.homepage.t-online.de/Konrad_Zuse_index_english_html/rechner_z1.html |access-date=2015-02-09}} 
* {{cite web |title=An informative website about Zuse Z1 |url=http://zuse-z1.zib.de}}
* {{cite web |title=A detailed walk-through of the Zuse Z1 major components |website=[[YouTube]] |url=https://www.youtube.com/watch?v=HDxs3-aJSAI}}
* {{cite web |title=The German Technology Museum presents the operational restored Z1|website=[[YouTube]] |url=https://www.youtube.com/watch?v=R5XnuT6ZLKg}}
https://www.youtube.com/watch?v=R5XnuT6ZLKg

{{Konrad zuse computer}}

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[[Category:1930s computers]]
[[Category:One-of-a-kind computers|Z01]]
[[Category:Mechanical computers]]
[[Category:German inventions of the Nazi period]]
[[Category:Computer-related introductions in 1938]]
[[Category:Konrad Zuse]]
[[Category:Computers designed in Germany]]