Editing History of computing hardware (section)

===Electronic data processing===
[[File:Atanasoff-Berry Computer at Durhum Center.jpg|thumb|[[Atanasoff–Berry Computer]] replica at first floor of Durham Center, [[Iowa State University]] ]]
Purely [[electronic circuit]] elements soon replaced their mechanical and electromechanical equivalents, at the same time that digital calculation replaced analog. Machines such as the [[Z3 (computer)|Z3]], the [[Atanasoff–Berry Computer]], the [[Colossus computer]]s, and the [[ENIAC]] were built by hand, using circuits containing relays or valves (vacuum tubes), and often used [[punched card]]s or [[punched tape|punched paper tape]] for input and as the main (non-volatile) storage medium.<ref>{{Cite journal |last=Guarnieri|first=M.|year=2012|title=The Age of Vacuum Tubes: Merging with Digital Computing &#91;Historical&#93; |journal=IEEE Industrial Electronics Magazine|volume=6 |issue=3|pages=52–55|doi=10.1109/MIE.2012.2207830 |s2cid=41800914}}</ref>

Engineer [[Tommy Flowers]] joined the telecommunications branch of the [[General Post Office]] in 1926. While working at the [[Post Office Research Station|research station]] in [[Dollis Hill]] in the 1930s, he began to explore the possible use of electronics for the [[telephone exchange]]. Experimental equipment that he built in 1934 went into operation 5 years later, converting a portion of the [[telephone exchange]] network into an electronic data processing system, using thousands of [[vacuum tube]]s.<ref name="stanf" />

In the US, in 1940 Arthur Dickinson (IBM) invented the first digital electronic computer.<ref>{{cite book |title=Building IBM: Shaping an Industry and its Technology|first=Emerson W.|last=Pugh|publisher=[[The MIT Press]]|year=1996}}</ref> This calculating device was fully electronic – control, calculations and output (the first electronic display).<ref>{{cite web |url=https://www.ibm.com/ibm/history/ibm100/us/en/icons/patents/ |access-date=2020-12-01 |title=Patents and Innovation |website=IBM 100 |date=7 March 2012 |archive-date=2020-12-02 |archive-url=https://web.archive.org/web/20201202140105/https://www.ibm.com/ibm/history/ibm100/us/en/icons/patents/ |url-status=live}}</ref> John Vincent Atanasoff and Clifford E. Berry of Iowa State University developed the Atanasoff–Berry Computer (ABC) in 1942,<ref>15 January 1941 notice in the ''Des Moines Register''</ref> the first binary electronic digital calculating device.<ref>{{cite book |title=The First Electronic Computer: the Atanasoff story |url=https://archive.org/details/firstelectronicc0000burk |url-access=registration |first1=Alice R. |last1=Burks |first2=Arthur W. |last2=Burks |year=1988 |location=Ann Arbor |publisher=University of Michigan Press |isbn=0-472-10090-4}}</ref> This design was semi-electronic (electro-mechanical control and electronic calculations), and used about 300 vacuum tubes, with capacitors fixed in a mechanically rotating drum for memory. However, its paper card writer/reader was unreliable and the regenerative drum contact system was mechanical. The machine's special-purpose nature and lack of changeable, [[stored-program computer|stored program]] distinguish it from modern computers.{{sfn|Copeland|2006|p=107}}

Computers whose logic was primarily built using vacuum tubes are now known as [[vacuum-tube computer|first generation computers]].