View source for Z2 (computer)

{{Short description|1940 electromechanical computer}}
{{Use dmy dates|date=July 2022|cs1-dates=y}}
{{Use list-defined references|date=July 2022}}
{{Infobox information appliance
| name         = Z2
| title        =
| aka          =
| logo         =
| image        = Zuse archive Z2.jpg
| caption      = Drawing of the Zuse Z2
| developer    = [[Konrad Zuse]]
| manufacturer =
| family       =
| type         = [[electromechanical computer|Electromechanical]] (mechanical and relay-based) [[digital computer]]
| generation   =
| releasedate  = {{Start date and age|1940}}
| lifespan     =
| price        =
| discontinued =
| unitssold    =
| unitsshipped =
| media        =
| os           =
| power        = 1000&nbsp;[[watt]]s
| soc          =
| cpu          = 600 electrical [[relay]] circuits
| CPUspeed     = ca. 5&nbsp;[[Hertz|Hz]]
| memory       = 64 words
| storage      =
| memory card  = [[Punch card]]s
| display      =
| graphics     =
| sound        =
| input        =
| controllers  =
| camera       =
| touchpad     =
| connectivity =
| platform     =
| service      =
| dimensions   =
| weight       = {{convert|300|kg|lb|lk=on|abbr=on}}
| topgame      =
| compatibility=
| predecessor  = [[Z1 (computer)|Z1]]
| successor    = [[Z3 (computer)|Z3]]
| related      =
| website      =
}}
The '''Z2''' was an [[electromechanical computer|electromechanical]] (mechanical and relay-based) [[digital computer]] that was completed by [[Konrad Zuse]] in 1940.<ref name="Weiss_1996"/><ref name="Williams_1985"/><ref name="DeMol_2007"/> It was an improvement on the [[Z1 (computer)|Z1]] Zuse built in his parents' home, which used the same mechanical [[computer memory|memory]]. In the Z2, he replaced the arithmetic and control logic with 600 electrical [[relay]] circuits, weighing over 600 pounds. 

The Z2 could read 64 [[Word (computer architecture)|words]] from punch cards. Photographs and plans for the Z2 were destroyed by the [[Allied bombing of Germany|Allied bombing]] during [[World War II]].<ref name="Zuse_2000"/> In contrast to the Z1, the Z2 used 16-bit [[fixed-point arithmetic]] instead of 22-bit [[floating point]].

Zuse presented the Z2 in 1940 to members of the DVL<ref name="Weiss_1996"/><ref name="Williams_1985"/><ref name="DeMol_2007"/> (today [[German Aerospace Center|DLR]]) and member {{ill|Alfred Teichmann|de|Alfred Teichmann (Bauingenieur)}}, whose support helped fund the successor model [[Z3 (computer)|Z3]].<ref name="Hellige_2004"/>

==Specifications==
{| class="wikitable"
|'''Frequency'''
|Ca. 5 Hertz
|-
|'''Arithmetic Unit'''
|Fixed point arithmetic unit with 16 bit word length
|-
|'''Average calculation Speed'''
|0.8 sec for addition operation
|-
|'''Number of Relays'''
|600
|-
|'''Memory'''
|64 words (same as Z1)
|-
|'''Power Consumption'''
|1000&nbsp;[[watt]]s
|-
|'''Weight'''
|{{convert|300|kg|lb|lk=on|abbr=on}}
|}<ref name="Zuse_2015"/>

==See also==
* [[Z4 (computer)|Z4]]

==References==
{{reflist|refs=
<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}}(NB. Z1 and Z2.)</ref>
<ref name="Williams_1985">{{cite book |title=A history of computing technology |language=en |author-last=Williams |author-first=Michael Roy |date=1985 |publisher=[[Prentice-Hall]] |isbn=978-0-13389917-7 |pages=219 |url=https://books.google.com/books?id=l3xQAAAAMAAJ&q=weekends |access-date=2022-07-10}} (NB. Also search the book for ''Luftfahrt'' - further part.)</ref>
<ref name="DeMol_2007">{{cite book |title=Tracing Unsolvability. A Mathematical, Historical and Philosophical Analysis with a Special Focus on Tag Systems |chapter=Chapter 4.1.3 Zuse’s Z1, Z2, Z3, Z4 and Plankalkül |author-last=De Mol |author-first=Liesbeth |date=2007 |page=212 |url=https://www.clps.ugent.be/sites/default/files/publications/dissertation.pdf |access-date=2018-05-12 |url-status=live |archive-url=https://web.archive.org/web/20220316014130/https://www.clps.ugent.be/sites/default/files/publications/dissertation.pdf |archive-date=2022-03-16}} [<!-- http://www.clps.ugent.be/research/publications/tracing-unsolvability-mathematical-historical-and-philosophical-analysis -->https://web.archive.org/web/20220709221245/https://www.clps.ugent.be/research/publications/tracing-unsolvability-mathematical-historical-and-philosophical-analysis] (xii+679 pages)</ref>
<ref name="Zuse_2000">{{cite web |title=Konrad Zuse's Z1 and Z3 Computers |author-last=Zuse |author-first=Horst |author-link=Horst Zuse |date=2000 |volume=Part 4 |work=The Life and Work of Konrad Zuse |publisher=EPE Online |url=http://www.epemag.com/zuse/part4a.htm |access-date=2008-06-17 |url-status=dead |archive-url=https://web.archive.org/web/20080601210541/http://www.epemag.com/zuse/part4a.htm |archive-date=2008-06-01}}</ref>
<ref name="Hellige_2004">{{cite book <!-- |author-first=Hartmut |author-last=Petzold |author-link=:de:Hartmut Petzold --> |editor-first=Hans Dieter |editor-last=Hellige |title=Geschichten der Informatik. Visionen, Paradigmen, Leitmotive. |language=de |trans-title= |publication-place=Berlin, Germany |publisher=[[Springer-Verlag]] |date=2004 |isbn=3-540-00217-0 |page=115}}</ref>
<ref name="Zuse_2015">{{cite web |title=Z2 Data Sheet |author-first=Horst |author-last=Zuse |author-link=Horst Zuse |date=2015  |url=http://www.horst-zuse.homepage.t-online.de/Konrad_Zuse_index_english_html/rechner_z2.html |access-date=2015-02-09 |url-status=live |archive-url=https://web.archive.org/web/20220222112939/http://www.horst-zuse.homepage.t-online.de/Konrad_Zuse_index_english_html/rechner_z2.html |archive-date=2022-02-22}}</ref>
}}

==Further reading==
* {{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==
* [http://www.horst-zuse.homepage.t-online.de/Konrad_Zuse_index_english_html/rechner_z2.html Z2] via [[Horst Zuse]] (son) web page

{{Konrad zuse computer}}

{{Authority control}}
[[Category:Electro-mechanical computers]]
[[Category:One-of-a-kind computers|Z02]]
[[Category:Mechanical computers]]
[[Category:Computer-related introductions in 1940]]
[[Category:Konrad Zuse]]
[[Category:German inventions of the Nazi period]]
[[Category:1940s computers]]
[[Category:Computers designed in Germany]]

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