tag:blogger.com,1999:blog-14584021587137574792024-03-21T01:21:43.942-07:00computersChathuranga and Menakahttp://www.blogger.com/profile/02083506018847115451noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-1458402158713757479.post-50073686609301883262008-10-10T10:48:00.001-07:002008-10-10T10:49:14.672-07:00History of computing<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjs0AMcJQ6JRntOF6SsvrqR0FtHoqWs8P7JpADukd5W37sgodFmj5-a57q6-9_Eil8q0C7Hekw4QN3Bq9k0UHX_CgY0ABZ7klpmD-qmdyHa98wBdaeuxF3DWu6xeIWsnuYknIpDK2mDw76R/s1600-h/180px-Jacquard.jpg"><img style="margin: 0pt 10px 10px 0pt; float: left; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjs0AMcJQ6JRntOF6SsvrqR0FtHoqWs8P7JpADukd5W37sgodFmj5-a57q6-9_Eil8q0C7Hekw4QN3Bq9k0UHX_CgY0ABZ7klpmD-qmdyHa98wBdaeuxF3DWu6xeIWsnuYknIpDK2mDw76R/s320/180px-Jacquard.jpg" alt="" id="BLOGGER_PHOTO_ID_5255583685241172690" border="0" /></a><br /><p>It is difficult to identify any one device as the earliest computer, partly because the term "computer" has been subject to varying interpretations over time. Originally, the term "computer" referred to a person who performed numerical calculations (a <a href="http://en.wikipedia.org/wiki/Human_computer" title="Human computer">human computer</a>), often with the aid of a <a href="http://en.wikipedia.org/wiki/Mechanical_calculating_device" title="Mechanical calculating device" class="mw-redirect">mechanical calculating device</a>.</p> <p>The history of the modern computer begins with two separate technologies - that of automated calculation and that of programmability.</p> <p>Examples of early mechanical calculating devices included the <a href="http://en.wikipedia.org/wiki/Abacus" title="Abacus">abacus</a>, the <a href="http://en.wikipedia.org/wiki/Slide_rule" title="Slide rule">slide rule</a> and arguably the <a href="http://en.wikipedia.org/wiki/Astrolabe" title="Astrolabe">astrolabe</a> and the <a href="http://en.wikipedia.org/wiki/Antikythera_mechanism" title="Antikythera mechanism">Antikythera mechanism</a> (which dates from about 150-100 BC). <a href="http://en.wikipedia.org/wiki/Hero_of_Alexandria" title="Hero of Alexandria">Hero of Alexandria</a> (c. 10–70 AD) built a mechanical theater which performed a play lasting 10 minutes and was operated by a complex system of ropes and drums that might be considered to be a means of deciding which parts of the mechanism performed which actions and when.<sup id="cite_ref-2" class="reference"><a href="http://en.wikipedia.org/wiki/Computer#cite_note-2" title="">[3]</a></sup> This is the essence of programmability.</p> <p>The "castle clock", an <a href="http://en.wikipedia.org/wiki/Astronomical_clock" title="Astronomical clock">astronomical clock</a> invented by <a href="http://en.wikipedia.org/wiki/Al-Jazari" title="Al-Jazari">Al-Jazari</a> in 1206, is considered to be the earliest <a href="http://en.wikipedia.org/wiki/Computer_programming" title="Computer programming">programmable</a> <a href="http://en.wikipedia.org/wiki/Analog_computer" title="Analog computer">analog computer</a>.<sup id="cite_ref-Ancient_Discoveries_3-0" class="reference"><a href="http://en.wikipedia.org/wiki/Computer#cite_note-Ancient_Discoveries-3" title="">[4]</a></sup> It displayed the <a href="http://en.wikipedia.org/wiki/Zodiac" title="Zodiac">zodiac</a>, the <a href="http://en.wikipedia.org/wiki/Heliocentric_orbit" title="Heliocentric orbit">solar</a> and <a href="http://en.wikipedia.org/wiki/Lunar_orbit" title="Lunar orbit">lunar orbits</a>, a <a href="http://en.wikipedia.org/wiki/Lunar_phase" title="Lunar phase">crescent moon</a>-shaped <a href="http://en.wikipedia.org/wiki/Pointer_%28computing%29" title="Pointer (computing)">pointer</a> travelling across a gateway causing <a href="http://en.wikipedia.org/wiki/Gate_operator" title="Gate operator">automatic doors</a> to open every <a href="http://en.wikipedia.org/wiki/Hour" title="Hour">hour</a>,<sup id="cite_ref-4" class="reference"><a href="http://en.wikipedia.org/wiki/Computer#cite_note-4" title="">[5]</a></sup><sup id="cite_ref-Hill2_5-0" class="reference"><a href="http://en.wikipedia.org/wiki/Computer#cite_note-Hill2-5" title="">[6]</a></sup> and five <a href="http://en.wikipedia.org/wiki/Robot" title="Robot">robotic</a> musicians who play music when struck by <a href="http://en.wikipedia.org/wiki/Lever" title="Lever">levers</a> operated by a <a href="http://en.wikipedia.org/wiki/Camshaft" title="Camshaft">camshaft</a> attached to a <a href="http://en.wikipedia.org/wiki/Water_wheel" title="Water wheel">water wheel</a>. The length of <a href="http://en.wikipedia.org/wiki/Daytime_%28astronomy%29" title="Daytime (astronomy)">day</a> and <a href="http://en.wikipedia.org/wiki/Night" title="Night">night</a> could be re-programmed every day in order to account for the changing lengths of day and night throughout the year.<sup id="cite_ref-Ancient_Discoveries_3-1" class="reference"><a href="http://en.wikipedia.org/wiki/Computer#cite_note-Ancient_Discoveries-3" title="">[4]</a></sup></p> <p>The end of the <a href="http://en.wikipedia.org/wiki/Middle_Ages" title="Middle Ages">Middle Ages</a> saw a re-invigoration of European mathematics and engineering, and <a href="http://en.wikipedia.org/wiki/Wilhelm_Schickard" title="Wilhelm Schickard">Wilhelm Schickard</a>'s 1623 device was the first of a number of mechanical calculators constructed by European engineers. However, none of those devices fit the modern definition of a computer because they could not be programmed.</p> <p>In 1801, <a href="http://en.wikipedia.org/wiki/Joseph_Marie_Jacquard" title="Joseph Marie Jacquard">Joseph Marie Jacquard</a> made an improvement to the <a href="http://en.wikipedia.org/wiki/Loom" title="Loom">textile loom</a> that used a series of <a href="http://en.wikipedia.org/wiki/Punch_card" title="Punch card" class="mw-redirect">punched paper cards</a> as a template to allow his loom to weave intricate patterns automatically. The resulting Jacquard loom was an important step in the development of computers because the use of punched cards to define woven patterns can be viewed as an early, albeit limited, form of programmability.</p> <p>It was the fusion of automatic calculation with programmability that produced the first recognizable computers. In 1837, <a href="http://en.wikipedia.org/wiki/Charles_Babbage" title="Charles Babbage">Charles Babbage</a> was the first to conceptualize and design a fully programmable mechanical computer that he called "The <a href="http://en.wikipedia.org/wiki/Analytical_engine" title="Analytical engine">Analytical Engine</a>".<sup id="cite_ref-6" class="reference"><a href="http://en.wikipedia.org/wiki/Computer#cite_note-6" title="">[7]</a></sup> Due to limited finances, and an inability to resist tinkering with the design, Babbage never actually built his Analytical Engine.</p> <p>Large-scale automated data processing of punched cards was performed for the <a href="http://en.wikipedia.org/wiki/United_States_Census,_1890" title="United States Census, 1890" class="mw-redirect">U.S. Census in 1890</a> by <a href="http://en.wikipedia.org/wiki/Tabulating_machine" title="Tabulating machine">tabulating machines</a> designed by <a href="http://en.wikipedia.org/wiki/Herman_Hollerith" title="Herman Hollerith">Herman Hollerith</a> and manufactured by the <a href="http://en.wikipedia.org/wiki/Computing_Tabulating_Recording_Corporation" title="Computing Tabulating Recording Corporation">Computing Tabulating Recording Corporation</a>, which later became <a href="http://en.wikipedia.org/wiki/IBM" title="IBM">IBM</a>. By the end of the 19th century a number of technologies that would later prove useful in the realization of practical computers had begun to appear: the <a href="http://en.wikipedia.org/wiki/Punch_card" title="Punch card" class="mw-redirect">punched card</a>, <a href="http://en.wikipedia.org/wiki/Boolean_algebra_%28logic%29" title="Boolean algebra (logic)">Boolean algebra</a>, the <a href="http://en.wikipedia.org/wiki/Vacuum_tube" title="Vacuum tube">vacuum tube</a> (thermionic valve) and the <a href="http://en.wikipedia.org/wiki/Teleprinter" title="Teleprinter">teleprinter</a>.</p> <p>During the first half of the 20th century, many scientific computing needs were met by increasingly sophisticated <a href="http://en.wikipedia.org/wiki/Analog_computer" title="Analog computer">analog computers</a>, which used a direct mechanical or <a href="http://en.wikipedia.org/wiki/Electricity" title="Electricity">electrical</a> model of the problem as a basis for <a href="http://en.wikipedia.org/wiki/Computation" title="Computation">computation</a>. However, these were not programmable and generally lacked the versatility and accuracy of modern digital computers.</p> <table class="wikitable" style="margin: 1em auto;"> <caption><i>Defining characteristics of some early digital computers of the 1940s</i> <small style="line-height: 130%;">(In the <a href="http://en.wikipedia.org/wiki/History_of_computing_hardware" title="History of computing hardware">history of computing hardware</a>)</small></caption> <tbody><tr> <th>Name</th> <th>First operational</th> <th>Numeral system</th> <th>Computing mechanism</th> <th><a href="http://en.wikipedia.org/wiki/Computer_program" title="Computer program">Programming</a></th> <th><a href="http://en.wikipedia.org/wiki/Turing_completeness" title="Turing completeness">Turing complete</a></th> </tr> <tr> <td style="background: rgb(236, 236, 236) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: black; text-align: left; padding-left: 0.5em; font-weight: bold;" class="table-rh"><a href="http://en.wikipedia.org/wiki/Konrad_Zuse" title="Konrad Zuse">Zuse</a> <a href="http://en.wikipedia.org/wiki/Z3_%28computer%29" title="Z3 (computer)">Z3</a> <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/Germany" title="Germany">Germany</a>)</small></td> <td>May 1941</td> <td><a href="http://en.wikipedia.org/wiki/Binary_numeral_system" title="Binary numeral system">Binary</a></td> <td><a href="http://en.wikipedia.org/wiki/Electromechanics" title="Electromechanics">Electro-mechanical</a></td> <td>Program-controlled by punched <a href="http://en.wikipedia.org/wiki/Film_stock" title="Film stock">film stock</a></td> <td>Yes <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/Z3_%28computer%29#Relation_to_the_concept_of_a_universal_Turing_machine" title="Z3 (computer)">1998</a>)</small></td> </tr> <tr> <td style="background: rgb(236, 236, 236) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: black; text-align: left; padding-left: 0.5em; font-weight: bold;" class="table-rh"><a href="http://en.wikipedia.org/wiki/Atanasoff%E2%80%93Berry_Computer" title="Atanasoff–Berry Computer">Atanasoff–Berry Computer</a> <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/US" title="US" class="mw-redirect">US</a>)</small></td> <td>Summer 1941</td> <td><a href="http://en.wikipedia.org/wiki/Binary_numeral_system" title="Binary numeral system">Binary</a></td> <td><a href="http://en.wikipedia.org/wiki/Electronics" title="Electronics">Electronic</a></td> <td>Not programmable—single purpose</td> <td>No</td> </tr> <tr> <td style="background: rgb(236, 236, 236) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: black; text-align: left; padding-left: 0.5em; font-weight: bold;" class="table-rh"><a href="http://en.wikipedia.org/wiki/Colossus_computer" title="Colossus computer">Colossus</a> <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/UK" title="UK" class="mw-redirect">UK</a>)</small></td> <td>January 1944</td> <td><a href="http://en.wikipedia.org/wiki/Binary_numeral_system" title="Binary numeral system">Binary</a></td> <td><a href="http://en.wikipedia.org/wiki/Electronics" title="Electronics">Electronic</a></td> <td>Program-controlled by patch cables and switches</td> <td>No</td> </tr> <tr> <td style="background: rgb(236, 236, 236) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: black; text-align: left; padding-left: 0.5em; font-weight: bold;" class="table-rh"><a href="http://en.wikipedia.org/wiki/Harvard_Mark_I" title="Harvard Mark I">Harvard Mark I – IBM ASCC</a> <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/US" title="US" class="mw-redirect">US</a>)</small></td> <td>1944</td> <td><a href="http://en.wikipedia.org/wiki/Decimal" title="Decimal">Decimal</a></td> <td><a href="http://en.wikipedia.org/wiki/Electromechanics" title="Electromechanics">Electro-mechanical</a></td> <td>Program-controlled by 24-channel <a href="http://en.wikipedia.org/wiki/Punched_tape" title="Punched tape">punched paper tape</a> (but no conditional branch)</td> <td>No</td> </tr> <tr> <td style="background: rgb(236, 236, 236) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: black; text-align: left; padding-left: 0.5em; font-weight: bold;" class="table-rh"><a href="http://en.wikipedia.org/wiki/ENIAC" title="ENIAC">ENIAC</a> <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/US" title="US" class="mw-redirect">US</a>)</small></td> <td>November 1945</td> <td><a href="http://en.wikipedia.org/wiki/Decimal" title="Decimal">Decimal</a></td> <td><a href="http://en.wikipedia.org/wiki/Electronics" title="Electronics">Electronic</a></td> <td>Program-controlled by patch cables and switches</td> <td>Yes</td> </tr> <tr> <td style="background: rgb(236, 236, 236) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: black; text-align: left; padding-left: 0.5em; font-weight: bold;" class="table-rh"><a href="http://en.wikipedia.org/wiki/Manchester_Small-Scale_Experimental_Machine" title="Manchester Small-Scale Experimental Machine">Manchester Small-Scale Experimental Machine</a> <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/UK" title="UK" class="mw-redirect">UK</a>)</small></td> <td>June 1948</td> <td><a href="http://en.wikipedia.org/wiki/Binary_numeral_system" title="Binary numeral system">Binary</a></td> <td><a href="http://en.wikipedia.org/wiki/Electronics" title="Electronics">Electronic</a></td> <td><a href="http://en.wikipedia.org/wiki/Stored-program" title="Stored-program" class="mw-redirect">Stored-program</a> in <a href="http://en.wikipedia.org/wiki/Williams_tube" title="Williams tube">Williams cathode ray tube memory</a></td> <td>Yes</td> </tr> <tr> <td style="background: rgb(236, 236, 236) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: black; text-align: left; padding-left: 0.5em; font-weight: bold;" class="table-rh"><a href="http://en.wikipedia.org/wiki/ENIAC" title="ENIAC">Modified ENIAC</a> <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/US" title="US" class="mw-redirect">US</a>)</small></td> <td>September 1948</td> <td><a href="http://en.wikipedia.org/wiki/Decimal" title="Decimal">Decimal</a></td> <td><a href="http://en.wikipedia.org/wiki/Electronics" title="Electronics">Electronic</a></td> <td>Program-controlled by patch cables and switches plus a primitive read-only stored programming mechanism using the Function Tables as program <a href="http://en.wikipedia.org/wiki/Read-only_memory" title="Read-only memory" class="mw-redirect">ROM</a></td> <td>Yes</td> </tr> <tr> <td style="background: rgb(236, 236, 236) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: black; text-align: left; padding-left: 0.5em; font-weight: bold;" class="table-rh"><a href="http://en.wikipedia.org/wiki/EDSAC" title="EDSAC" class="mw-redirect">EDSAC</a> <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/UK" title="UK" class="mw-redirect">UK</a>)</small></td> <td>May 1949</td> <td><a href="http://en.wikipedia.org/wiki/Binary_numeral_system" title="Binary numeral system">Binary</a></td> <td><a href="http://en.wikipedia.org/wiki/Electronics" title="Electronics">Electronic</a></td> <td><a href="http://en.wikipedia.org/wiki/Stored-program" title="Stored-program" class="mw-redirect">Stored-program</a> in mercury <a href="http://en.wikipedia.org/wiki/Delay_line_memory" title="Delay line memory">delay line memory</a></td> <td>Yes</td> </tr> <tr> <td style="background: rgb(236, 236, 236) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: black; text-align: left; padding-left: 0.5em; font-weight: bold;" class="table-rh"><a href="http://en.wikipedia.org/wiki/Manchester_Mark_I" title="Manchester Mark I">Manchester Mark I</a> <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/UK" title="UK" class="mw-redirect">UK</a>)</small></td> <td>October 1949</td> <td><a href="http://en.wikipedia.org/wiki/Binary_numeral_system" title="Binary numeral system">Binary</a></td> <td><a href="http://en.wikipedia.org/wiki/Electronics" title="Electronics">Electronic</a></td> <td><a href="http://en.wikipedia.org/wiki/Stored-program" title="Stored-program" class="mw-redirect">Stored-program</a> in <a href="http://en.wikipedia.org/wiki/Williams_tube" title="Williams tube">Williams cathode ray tube memory</a> and <a href="http://en.wikipedia.org/wiki/Drum_memory" title="Drum memory">magnetic drum</a> memory</td> <td>Yes</td> </tr> <tr> <td style="background: rgb(236, 236, 236) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: black; text-align: left; padding-left: 0.5em; font-weight: bold;" class="table-rh"><a href="http://en.wikipedia.org/wiki/CSIRAC" title="CSIRAC">CSIRAC</a> <small style="line-height: 130%;">(<a href="http://en.wikipedia.org/wiki/Australia" title="Australia">Australia</a>)</small></td> <td>November 1949</td> <td><a href="http://en.wikipedia.org/wiki/Binary_numeral_system" title="Binary numeral system">Binary</a></td> <td><a href="http://en.wikipedia.org/wiki/Electronics" title="Electronics">Electronic</a></td> <td><a href="http://en.wikipedia.org/wiki/Stored-program" title="Stored-program" class="mw-redirect">Stored-program</a> in mercury <a href="http://en.wikipedia.org/wiki/Delay_line_memory" title="Delay line memory">delay line memory</a></td> <td>Yes</td> </tr> </tbody></table> <p><br /></p> <p>A succession of steadily more powerful and flexible computing devices were constructed in the 1930s and 1940s, gradually adding the key features that are seen in modern computers. The use of digital electronics (largely invented by <a href="http://en.wikipedia.org/wiki/Claude_Shannon" title="Claude Shannon">Claude Shannon</a> in 1937) and more flexible programmability were vitally important steps, but defining one point along this road as "the first digital electronic computer" is difficult <span class="reference" id="ref_shannon1940a"><a href="http://en.wikipedia.org/wiki/Computer#endnote_shannon1940a" title="">(Shannon 1940)</a></span>. Notable achievements include:</p> <div class="thumb tright"> <div class="thumbinner" style="width: 202px;"><a href="http://en.wikipedia.org/wiki/Image:EDSAC_%2810%29.jpg" class="image" title="EDSAC was one of the first computers to implement the stored program (von Neumann) architecture."><img alt="EDSAC was one of the first computers to implement the stored program (von Neumann) architecture." src="http://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/EDSAC_%2810%29.jpg/200px-EDSAC_%2810%29.jpg" class="thumbimage" border="0" height="244" width="200" /></a> <div class="thumbcaption"> <div class="magnify"><a href="http://en.wikipedia.org/wiki/Image:EDSAC_%2810%29.jpg" class="internal" title="Enlarge"><img src="http://en.wikipedia.org/skins-1.5/common/images/magnify-clip.png" alt="" height="11" width="15" /></a></div> <a href="http://en.wikipedia.org/wiki/EDSAC" title="EDSAC" class="mw-redirect">EDSAC</a> was one of the first computers to implement the stored program (<a href="http://en.wikipedia.org/wiki/Von_Neumann_architecture" title="Von Neumann architecture">von Neumann</a>) architecture.</div> </div> </div> <ul><li><a href="http://en.wikipedia.org/wiki/Konrad_Zuse" title="Konrad Zuse">Konrad Zuse</a>'s <a href="http://en.wikipedia.org/wiki/Electromechanics" title="Electromechanics">electromechanical</a> "Z machines". The <a href="http://en.wikipedia.org/wiki/Z3_%28computer%29" title="Z3 (computer)">Z3</a> (1941) was the first working machine featuring <a href="http://en.wikipedia.org/wiki/Binary_numeral_system" title="Binary numeral system">binary</a> arithmetic, including floating point arithmetic and a measure of programmability. In 1998 the Z3 was proved to be <a href="http://en.wikipedia.org/wiki/Turing_completeness" title="Turing completeness">Turing complete</a>, therefore being the world's first operational computer.</li><li>The non-programmable <a href="http://en.wikipedia.org/wiki/Atanasoff%E2%80%93Berry_Computer" title="Atanasoff–Berry Computer">Atanasoff–Berry Computer</a> (1941) which used vacuum tube based <a href="http://en.wikipedia.org/wiki/Computation" title="Computation">computation</a>, binary numbers, and <a href="http://en.wikipedia.org/wiki/Regenerative_capacitor_memory" title="Regenerative capacitor memory">regenerative capacitor memory</a>.</li><li>The secret British <a href="http://en.wikipedia.org/wiki/Colossus_computer" title="Colossus computer">Colossus computers</a> (1943)<sup id="cite_ref-7" class="reference"><a href="http://en.wikipedia.org/wiki/Computer#cite_note-7" title="">[8]</a></sup>, which had limited programmability but demonstrated that a device using thousands of tubes could be reasonably reliable and electronically reprogrammable. It was used for <a href="http://en.wikipedia.org/wiki/Cryptanalysis" title="Cryptanalysis">breaking</a> German wartime codes.</li><li>The <a href="http://en.wikipedia.org/wiki/Harvard_Mark_I" title="Harvard Mark I">Harvard Mark I</a> (1944), a large-scale electromechanical computer with limited programmability.</li><li>The U.S. Army's <a href="http://en.wikipedia.org/wiki/Ballistics_Research_Laboratory" title="Ballistics Research Laboratory" class="mw-redirect">Ballistics Research Laboratory</a> <a href="http://en.wikipedia.org/wiki/ENIAC" title="ENIAC">ENIAC</a> (1946), which used <a href="http://en.wikipedia.org/wiki/Decimal" title="Decimal">decimal</a> arithmetic and is sometimes called the first general purpose <a href="http://en.wikipedia.org/wiki/Electronics" title="Electronics">electronic</a> computer (since <a href="http://en.wikipedia.org/wiki/Konrad_Zuse" title="Konrad Zuse">Konrad Zuse</a>'s <a href="http://en.wikipedia.org/wiki/Z3_%28computer%29" title="Z3 (computer)">Z3</a> of 1941 used <a href="http://en.wikipedia.org/wiki/Electromagnets" title="Electromagnets" class="mw-redirect">electromagnets</a> instead of <a href="http://en.wikipedia.org/wiki/Electronics" title="Electronics">electronics</a>). Initially, however, ENIAC had an inflexible architecture which essentially required rewiring to change its programming.</li></ul> <p>Several developers of ENIAC, recognizing its flaws, came up with a far more flexible and elegant design, which came to be known as the "stored program architecture" or <a href="http://en.wikipedia.org/wiki/Von_Neumann_architecture" title="Von Neumann architecture">von Neumann architecture</a>. This design was first formally described by <a href="http://en.wikipedia.org/wiki/John_von_Neumann" title="John von Neumann">John von Neumann</a> in the paper <i><a href="http://en.wikipedia.org/wiki/First_Draft_of_a_Report_on_the_EDVAC" title="First Draft of a Report on the EDVAC">First Draft of a Report on the EDVAC</a></i>, distributed in 1945. A number of projects to develop computers based on the stored-program architecture commenced around this time, the first of these being completed in <a href="http://en.wikipedia.org/wiki/Great_Britain" title="Great Britain">Great Britain</a>. The first to be demonstrated working was the <a href="http://en.wikipedia.org/wiki/Manchester_Small-Scale_Experimental_Machine" title="Manchester Small-Scale Experimental Machine">Manchester Small-Scale Experimental Machine</a> (SSEM or "Baby"), while the <a href="http://en.wikipedia.org/wiki/EDSAC" title="EDSAC" class="mw-redirect">EDSAC</a>, completed a year after SSEM, was the first practical implementation of the stored program design. Shortly thereafter, the machine originally described by von Neumann's paper—<a href="http://en.wikipedia.org/wiki/EDVAC" title="EDVAC">EDVAC</a>—was completed but did not see full-time use for an additional two years.</p> <p>Nearly all modern computers implement some form of the stored-program architecture, making it the single trait by which the word "computer" is now defined. While the technologies used in computers have changed dramatically since the first electronic, general-purpose computers of the 1940s, most still use the von Neumann architecture.</p> <div class="thumb tright"> <div class="thumbinner" style="width: 202px;"><a href="http://en.wikipedia.org/wiki/Image:80486dx2-large.jpg" class="image" title="Microprocessors are miniaturized devices that often implement stored program CPUs."><img alt="Microprocessors are miniaturized devices that often implement stored program CPUs." src="http://upload.wikimedia.org/wikipedia/commons/thumb/0/02/80486dx2-large.jpg/200px-80486dx2-large.jpg" class="thumbimage" border="0" height="149" width="200" /></a> <div class="thumbcaption"> <div class="magnify"><a href="http://en.wikipedia.org/wiki/Image:80486dx2-large.jpg" class="internal" title="Enlarge"><img src="http://en.wikipedia.org/skins-1.5/common/images/magnify-clip.png" alt="" height="11" width="15" /></a></div> <a href="http://en.wikipedia.org/wiki/Microprocessors" title="Microprocessors" class="mw-redirect">Microprocessors</a> are miniaturized devices that often implement stored program <a href="http://en.wikipedia.org/wiki/CPU" title="CPU" class="mw-redirect">CPUs</a>.</div> </div> </div> <p>Computers that used <a href="http://en.wikipedia.org/wiki/Vacuum_tube" title="Vacuum tube">vacuum tubes</a> as their electronic elements were in use throughout the 1950s. Vacuum tube electronics were largely replaced in the 1960s by <a href="http://en.wikipedia.org/wiki/Transistor" title="Transistor">transistor</a>-based electronics, which are smaller, faster, cheaper to produce, require less power, and are more reliable. In the 1970s, <a href="http://en.wikipedia.org/wiki/Integrated_circuit" title="Integrated circuit">integrated circuit</a> technology and the subsequent creation of <a href="http://en.wikipedia.org/wiki/Microprocessor" title="Microprocessor">microprocessors</a>, such as the <a href="http://en.wikipedia.org/wiki/Intel_4004" title="Intel 4004">Intel 4004</a>, further decreased size and cost and further increased speed and reliability of computers. By the 1980s, computers became sufficiently small and cheap to replace simple mechanical controls in domestic appliances such as <a href="http://en.wikipedia.org/wiki/Washing_machines" title="Washing machines" class="mw-redirect">washing machines</a>. The 1980s also witnessed <a href="http://en.wikipedia.org/wiki/Home_computer" title="Home computer">home computers</a> and the now ubiquitous <a href="http://en.wikipedia.org/wiki/Personal_computer" title="Personal computer">personal computer</a>. With the evolution of the <a href="http://en.wikipedia.org/wiki/Internet" title="Internet">Internet</a>, personal computers are becoming as common as the <a href="http://en.wikipedia.org/wiki/Television" title="Television">television</a> and the <a href="http://en.wikipedia.org/wiki/Telephone" title="Telephone">telephone</a> in the household.</p>Chathuranga and Menakahttp://www.blogger.com/profile/02083506018847115451noreply@blogger.com0tag:blogger.com,1999:blog-1458402158713757479.post-3541813410723042052008-10-10T10:43:00.001-07:002008-10-10T10:47:26.529-07:00Computers<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7PXKyj2B55KdBL6FbVXR9Le1roa1qHOyFrYryoQvAJpq9Ii1bkSVj5ln5MWZt9VjQKgjQwKCAMLkzErmbUgFD_opVNp1-2YQH55GEFv3u92fQWaFtEu_shgXIius-X25iUrrmHsfY61zd/s1600-h/180px-Columbia_Supercomputer_-_NASA_Advanced_Supercomputing_.jpg"><img style="margin: 0pt 0pt 10px 10px; float: right; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7PXKyj2B55KdBL6FbVXR9Le1roa1qHOyFrYryoQvAJpq9Ii1bkSVj5ln5MWZt9VjQKgjQwKCAMLkzErmbUgFD_opVNp1-2YQH55GEFv3u92fQWaFtEu_shgXIius-X25iUrrmHsfY61zd/s320/180px-Columbia_Supercomputer_-_NASA_Advanced_Supercomputing_.jpg" alt="" id="BLOGGER_PHOTO_ID_5255582966784565538" border="0" /></a><br /><a href="http://en.wikipedia.org/wiki/Machine" title="Machine">machine</a> that manipulates <a href="http://en.wikipedia.org/wiki/Data_%28computing%29" title="Data (computing)">data</a> according to a list of <a href="http://en.wikipedia.org/wiki/Code_%28computer_programming%29" title="Code (computer programming)" class="mw-redirect">instructions</a>. <p>The first devices that resemble modern computers date to the mid-20th century (1940–1945), although the computer concept and various machines similar to computers existed earlier. Early electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers(<a href="http://en.wikipedia.org/wiki/PC" title="PC">PC</a>).<sup id="cite_ref-0" class="reference"><a href="http://en.wikipedia.org/wiki/Computer#cite_note-0" title="">[1]</a></sup> Modern computers are based on tiny <a href="http://en.wikipedia.org/wiki/Integrated_circuit" title="Integrated circuit">integrated circuits</a> and are millions to billions of times more capable while occupying a fraction of the space.<sup id="cite_ref-1" class="reference"><a href="http://en.wikipedia.org/wiki/Computer#cite_note-1" title="">[2]</a></sup> Today, simple computers may be made small enough to fit into a <a href="http://en.wikipedia.org/wiki/Watch" title="Watch">wristwatch</a> and be powered from a <a href="http://en.wikipedia.org/wiki/Watch_battery" title="Watch battery" class="mw-redirect">watch battery</a>. <a href="http://en.wikipedia.org/wiki/Personal_computer" title="Personal computer">Personal computers</a>, in various forms, are <a href="http://en.wikipedia.org/wiki/Icons" title="Icons" class="mw-redirect">icons</a> of the <a href="http://en.wikipedia.org/wiki/Information_Age" title="Information Age">Information Age</a> and are what most people think of as "a computer"; however, the most common form of computer in use today is the <a href="http://en.wikipedia.org/wiki/Embedded_computer" title="Embedded computer" class="mw-redirect">embedded computer</a>. Embedded computers are small, simple devices that are used to control other devices — for example, they may be found in machines ranging from <a href="http://en.wikipedia.org/wiki/Fighter_aircraft" title="Fighter aircraft">fighter aircraft</a> to <a href="http://en.wikipedia.org/wiki/Industrial_robot" title="Industrial robot">industrial robots</a>, <a href="http://en.wikipedia.org/wiki/Digital_camera" title="Digital camera">digital cameras</a>, and <a href="http://en.wikipedia.org/wiki/Toy" title="Toy">children's toys</a>.</p> <p>The ability to store and execute lists of instructions called <i><a href="http://en.wikipedia.org/wiki/Computer_program" title="Computer program">programs</a></i> makes computers extremely versatile and distinguishes them from <a href="http://en.wikipedia.org/wiki/Calculator" title="Calculator">calculators</a>. The <a href="http://en.wikipedia.org/wiki/Church%E2%80%93Turing_thesis" title="Church–Turing thesis">Church–Turing thesis</a> is a mathematical statement of this versatility: any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with capability and complexity ranging from that of a <a href="http://en.wikipedia.org/wiki/Personal_digital_assistant" title="Personal digital assistant">personal digital assistant</a> to a <a href="http://en.wikipedia.org/wiki/Supercomputer" title="Supercomputer">supercomputer</a> are all able to perform the same computational tasks given enough time and storage capacity.</p>Chathuranga and Menakahttp://www.blogger.com/profile/02083506018847115451noreply@blogger.com0tag:blogger.com,1999:blog-1458402158713757479.post-3014088281497606252008-10-10T10:38:00.000-07:002008-10-10T10:42:50.368-07:00Further topics<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrxZjKN8tYpvFLfwZbxkLRuEbYcEH6LLpXkFfGsjKXfSs501iDbXB6TesWZvgfVyFj1M0_WYcNb13y5sI435wuCsYw4hYlVaMDwvnDSihiDC6jA589Z72RUlNfYTztYBbl5GcoimM2r_kp/s1600-h/180px-HDDspin.JPG"><img style="margin: 0pt 0pt 10px 10px; float: right; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrxZjKN8tYpvFLfwZbxkLRuEbYcEH6LLpXkFfGsjKXfSs501iDbXB6TesWZvgfVyFj1M0_WYcNb13y5sI435wuCsYw4hYlVaMDwvnDSihiDC6jA589Z72RUlNfYTztYBbl5GcoimM2r_kp/s320/180px-HDDspin.JPG" alt="" id="BLOGGER_PHOTO_ID_5255581924738884642" border="0" /></a><br /><h3><span class="mw-headline">Hardware</span></h3> <dl><dd> <div class="noprint relarticle mainarticle"><i>Main article: <a href="http://en.wikipedia.org/wiki/Computer_hardware" title="Computer hardware">Computer hardware</a></i></div> </dd></dl> <p>The term <b>hardware</b> covers all of those parts of a computer that are tangible objects. Circuits, displays, power supplies, cables, keyboards, printers and mice are all hardware.</p> <table class="wikitable"> <caption><b><a href="http://en.wikipedia.org/wiki/History_of_computing_hardware" title="History of computing hardware">History of computing hardware</a></b></caption> <tbody><tr> <td rowspan="2">First Generation (Mechanical/Electromechanical)</td> <td>Calculators</td> <td><a href="http://en.wikipedia.org/wiki/Antikythera_mechanism" title="Antikythera mechanism">Antikythera mechanism</a>, <a href="http://en.wikipedia.org/wiki/Difference_Engine" title="Difference Engine" class="mw-redirect">Difference Engine</a>, <a href="http://en.wikipedia.org/wiki/Norden_bombsight" title="Norden bombsight">Norden bombsight</a></td> </tr> <tr> <td>Programmable Devices</td> <td><a href="http://en.wikipedia.org/wiki/Jacquard_loom" title="Jacquard loom">Jacquard loom</a>, <a href="http://en.wikipedia.org/wiki/Analytical_Engine" title="Analytical Engine" class="mw-redirect">Analytical Engine</a>, <a href="http://en.wikipedia.org/wiki/Harvard_Mark_I" title="Harvard Mark I">Harvard Mark I</a>, <a href="http://en.wikipedia.org/wiki/Z3_%28computer%29" title="Z3 (computer)">Z3</a></td> </tr> <tr> <td rowspan="2">Second Generation (Vacuum Tubes)</td> <td>Calculators</td> <td><a href="http://en.wikipedia.org/wiki/Atanasoff%E2%80%93Berry_Computer" title="Atanasoff–Berry Computer">Atanasoff–Berry Computer</a>, <a href="http://en.wikipedia.org/wiki/IBM_604" title="IBM 604">IBM 604</a>, <a href="http://en.wikipedia.org/wiki/UNIVAC_60" title="UNIVAC 60" class="mw-redirect">UNIVAC 60</a>, <a href="http://en.wikipedia.org/wiki/UNIVAC_120" title="UNIVAC 120" class="mw-redirect">UNIVAC 120</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/List_of_vacuum_tube_computers" title="List of vacuum tube computers">Programmable Devices</a></td> <td><a href="http://en.wikipedia.org/wiki/Colossus_computer" title="Colossus computer">Colossus</a>, <a href="http://en.wikipedia.org/wiki/ENIAC" title="ENIAC">ENIAC</a>, <a href="http://en.wikipedia.org/wiki/Manchester_Small-Scale_Experimental_Machine" title="Manchester Small-Scale Experimental Machine">Manchester Small-Scale Experimental Machine</a>, <a href="http://en.wikipedia.org/wiki/EDSAC" title="EDSAC" class="mw-redirect">EDSAC</a>, <a href="http://en.wikipedia.org/wiki/Manchester_Mark_I" title="Manchester Mark I">Manchester Mark I</a>, <a href="http://en.wikipedia.org/wiki/CSIRAC" title="CSIRAC">CSIRAC</a>, <a href="http://en.wikipedia.org/wiki/EDVAC" title="EDVAC">EDVAC</a>, <a href="http://en.wikipedia.org/wiki/UNIVAC_I" title="UNIVAC I">UNIVAC I</a>, <a href="http://en.wikipedia.org/wiki/IBM_701" title="IBM 701">IBM 701</a>, <a href="http://en.wikipedia.org/wiki/IBM_702" title="IBM 702">IBM 702</a>, <a href="http://en.wikipedia.org/wiki/IBM_650" title="IBM 650">IBM 650</a>, <a href="http://en.wikipedia.org/wiki/Z22" title="Z22">Z22</a></td> </tr> <tr> <td rowspan="2">Third Generation (Discrete transistors and SSI, MSI, LSI <a href="http://en.wikipedia.org/wiki/Integrated_circuits" title="Integrated circuits" class="mw-redirect">Integrated circuits</a>)</td> <td><a href="http://en.wikipedia.org/wiki/Mainframe_computer" title="Mainframe computer">Mainframes</a></td> <td><a href="http://en.wikipedia.org/wiki/IBM_7090" title="IBM 7090">IBM 7090</a>, <a href="http://en.wikipedia.org/wiki/IBM_7080" title="IBM 7080">IBM 7080</a>, <a href="http://en.wikipedia.org/wiki/System/360" title="System/360" class="mw-redirect">System/360</a>, <a href="http://en.wikipedia.org/wiki/BUNCH" title="BUNCH">BUNCH</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Minicomputer" title="Minicomputer">Minicomputer</a></td> <td><a href="http://en.wikipedia.org/wiki/PDP-8" title="PDP-8">PDP-8</a>, <a href="http://en.wikipedia.org/wiki/PDP-11" title="PDP-11">PDP-11</a>, <a href="http://en.wikipedia.org/wiki/System/32" title="System/32" class="mw-redirect">System/32</a>, <a href="http://en.wikipedia.org/wiki/System/36" title="System/36" class="mw-redirect">System/36</a></td> </tr> <tr> <td rowspan="8">Fourth Generation (VLSI integrated circuits)</td> <td>Minicomputer</td> <td><a href="http://en.wikipedia.org/wiki/VAX" title="VAX">VAX</a>, <a href="http://en.wikipedia.org/wiki/IBM_System_i" title="IBM System i">IBM System i</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/4-bit" title="4-bit">4-bit</a> microcomputer</td> <td><a href="http://en.wikipedia.org/wiki/Intel_4004" title="Intel 4004">Intel 4004</a>, <a href="http://en.wikipedia.org/wiki/Intel_4040" title="Intel 4040">Intel 4040</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/8-bit" title="8-bit">8-bit</a> microcomputer</td> <td><a href="http://en.wikipedia.org/wiki/Intel_8008" title="Intel 8008">Intel 8008</a>, <a href="http://en.wikipedia.org/wiki/Intel_8080" title="Intel 8080">Intel 8080</a>, <a href="http://en.wikipedia.org/wiki/Motorola_6800" title="Motorola 6800">Motorola 6800</a>, <a href="http://en.wikipedia.org/wiki/Motorola_6809" title="Motorola 6809">Motorola 6809</a>, <a href="http://en.wikipedia.org/wiki/MOS_Technology_6502" title="MOS Technology 6502">MOS Technology 6502</a>, <a href="http://en.wikipedia.org/wiki/Zilog_Z80" title="Zilog Z80">Zilog Z80</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/16-bit" title="16-bit">16-bit</a> microcomputer</td> <td><a href="http://en.wikipedia.org/wiki/Intel_8088" title="Intel 8088">Intel 8088</a>, <a href="http://en.wikipedia.org/wiki/Zilog_Z8000" title="Zilog Z8000">Zilog Z8000</a>, <a href="http://en.wikipedia.org/wiki/WDC_65816/65802" title="WDC 65816/65802">WDC 65816/65802</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/32-bit" title="32-bit">32-bit</a> microcomputer</td> <td><a href="http://en.wikipedia.org/wiki/Intel_80386" title="Intel 80386">Intel 80386</a>, <a href="http://en.wikipedia.org/wiki/Pentium" title="Pentium">Pentium</a>, <a href="http://en.wikipedia.org/wiki/Motorola_68000" title="Motorola 68000">Motorola 68000</a>, <a href="http://en.wikipedia.org/wiki/ARM_architecture" title="ARM architecture">ARM architecture</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/64-bit" title="64-bit">64-bit</a> microcomputer<sup id="cite_ref-19" class="reference"><a href="http://en.wikipedia.org/wiki/Computer#cite_note-19" title="">[20]</a></sup></td> <td><a href="http://en.wikipedia.org/wiki/DEC_Alpha" title="DEC Alpha">Alpha</a>, <a href="http://en.wikipedia.org/wiki/MIPS_architecture" title="MIPS architecture">MIPS</a>, <a href="http://en.wikipedia.org/wiki/PA-RISC" title="PA-RISC" class="mw-redirect">PA-RISC</a>, <a href="http://en.wikipedia.org/wiki/PowerPC" title="PowerPC">PowerPC</a>, <a href="http://en.wikipedia.org/wiki/SPARC" title="SPARC">SPARC</a>, <a href="http://en.wikipedia.org/wiki/X86-64" title="X86-64">x86-64</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Embedded_system" title="Embedded system">Embedded computer</a></td> <td><a href="http://en.wikipedia.org/wiki/Intel_8048" title="Intel 8048">Intel 8048</a>, <a href="http://en.wikipedia.org/wiki/Intel_8051" title="Intel 8051">Intel 8051</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Personal_computer" title="Personal computer">Personal computer</a></td> <td><a href="http://en.wikipedia.org/wiki/Desktop_computer" title="Desktop computer">Desktop computer</a>, <a href="http://en.wikipedia.org/wiki/Home_computer" title="Home computer">Home computer</a>, <a href="http://en.wikipedia.org/wiki/Laptop_computer" title="Laptop computer" class="mw-redirect">Laptop computer</a>, <a href="http://en.wikipedia.org/wiki/Personal_digital_assistant" title="Personal digital assistant">Personal digital assistant</a> (PDA), <a href="http://en.wikipedia.org/wiki/Portable_computer" title="Portable computer">Portable computer</a>, <a href="http://en.wikipedia.org/wiki/Tablet_computer" title="Tablet computer" class="mw-redirect">Tablet computer</a>, <a href="http://en.wikipedia.org/wiki/Wearable_computer" title="Wearable computer">Wearable computer</a></td> </tr> <tr> <td rowspan="1">Theoretical/experimental</td> <td><a href="http://en.wikipedia.org/wiki/Quantum_computer" title="Quantum computer">Quantum computer</a>, <a href="http://en.wikipedia.org/wiki/Chemical_computer" title="Chemical computer">Chemical computer</a>, <a href="http://en.wikipedia.org/wiki/DNA_computing" title="DNA computing">DNA computing</a>, <a href="http://en.wikipedia.org/wiki/Optical_computer" title="Optical computer">Optical computer</a>, <a href="http://en.wikipedia.org/wiki/Spintronics" title="Spintronics">Spintronics based computer</a></td> </tr> </tbody></table> <table class="wikitable"> <caption><b>Other Hardware Topics</b></caption> <tbody><tr> <td rowspan="3"><a href="http://en.wikipedia.org/wiki/Peripheral" title="Peripheral">Peripheral device</a> (<a href="http://en.wikipedia.org/wiki/Input/output" title="Input/output">Input/output</a>)</td> <td>Input</td> <td><a href="http://en.wikipedia.org/wiki/Mouse_%28computing%29" title="Mouse (computing)">Mouse</a>, <a href="http://en.wikipedia.org/wiki/Computer_keyboard" title="Computer keyboard" class="mw-redirect">Keyboard</a>, <a href="http://en.wikipedia.org/wiki/Joystick" title="Joystick">Joystick</a>, <a href="http://en.wikipedia.org/wiki/Image_scanner" title="Image scanner">Image scanner</a></td> </tr> <tr> <td>Output</td> <td><a href="http://en.wikipedia.org/wiki/Computer_monitor" title="Computer monitor" class="mw-redirect">Monitor</a>, <a href="http://en.wikipedia.org/wiki/Computer_printer" title="Computer printer" class="mw-redirect">Printer</a></td> </tr> <tr> <td>Both</td> <td><a href="http://en.wikipedia.org/wiki/Floppy_disk_drive" title="Floppy disk drive" class="mw-redirect">Floppy disk drive</a>, <a href="http://en.wikipedia.org/wiki/Hard_disk" title="Hard disk" class="mw-redirect">Hard disk</a>, <a href="http://en.wikipedia.org/wiki/Optical_disc" title="Optical disc">Optical disc</a> drive, <a href="http://en.wikipedia.org/wiki/Teleprinter" title="Teleprinter">Teleprinter</a></td> </tr> <tr> <td rowspan="2"><a href="http://en.wikipedia.org/wiki/Computer_bus" title="Computer bus" class="mw-redirect">Computer busses</a></td> <td>Short range</td> <td><a href="http://en.wikipedia.org/wiki/RS-232" title="RS-232">RS-232</a>, <a href="http://en.wikipedia.org/wiki/SCSI" title="SCSI">SCSI</a>, <a href="http://en.wikipedia.org/wiki/Peripheral_Component_Interconnect" title="Peripheral Component Interconnect">PCI</a>, <a href="http://en.wikipedia.org/wiki/USB" title="USB" class="mw-redirect">USB</a></td> </tr> <tr> <td>Long range (<a href="http://en.wikipedia.org/wiki/Computer_networking" title="Computer networking">Computer networking</a>)</td> <td><a href="http://en.wikipedia.org/wiki/Ethernet" title="Ethernet">Ethernet</a>, <a href="http://en.wikipedia.org/wiki/Asynchronous_Transfer_Mode" title="Asynchronous Transfer Mode">ATM</a>, <a href="http://en.wikipedia.org/wiki/Fiber_distributed_data_interface" title="Fiber distributed data interface">FDDI</a></td> </tr> </tbody></table> <p><a name="Software" id="Software"></a></p> <h3><span class="mw-headline">Software</span></h3> <dl><dd> <div class="noprint relarticle mainarticle"><i>Main article: <a href="http://en.wikipedia.org/wiki/Computer_software" title="Computer software">Computer software</a></i></div> </dd></dl> <p><b>Software</b> refers to parts of the computer which do not have a material form, such as programs, data, protocols, etc. When software is stored in hardware that cannot easily be modified (such as <a href="http://en.wikipedia.org/wiki/BIOS" title="BIOS">BIOS</a> <a href="http://en.wikipedia.org/wiki/Read-only_memory" title="Read-only memory" class="mw-redirect">ROM</a> in an <a href="http://en.wikipedia.org/wiki/IBM_PC_compatible" title="IBM PC compatible">IBM PC compatible</a>), it is sometimes called "firmware" to indicate that it falls into an uncertain area somewhere between hardware and software.</p> <table class="wikitable"> <caption><b><a href="http://en.wikipedia.org/wiki/Computer_software" title="Computer software">Computer software</a></b></caption> <tbody><tr> <td rowspan="7"><a href="http://en.wikipedia.org/wiki/Operating_system" title="Operating system">Operating system</a></td> <td><a href="http://en.wikipedia.org/wiki/Unix" title="Unix">Unix</a>/<a href="http://en.wikipedia.org/wiki/Berkeley_Software_Distribution" title="Berkeley Software Distribution">BSD</a></td> <td><a href="http://en.wikipedia.org/wiki/UNIX_System_V" title="UNIX System V">UNIX System V</a>, <a href="http://en.wikipedia.org/wiki/AIX_operating_system" title="AIX operating system" class="mw-redirect">AIX</a>, <a href="http://en.wikipedia.org/wiki/HP-UX" title="HP-UX">HP-UX</a>, <a href="http://en.wikipedia.org/wiki/Solaris_Operating_System" title="Solaris Operating System" class="mw-redirect">Solaris</a> (<a href="http://en.wikipedia.org/wiki/SunOS" title="SunOS">SunOS</a>), <a href="http://en.wikipedia.org/wiki/IRIX" title="IRIX">IRIX</a>, <a href="http://en.wikipedia.org/wiki/List_of_BSD_operating_systems" title="List of BSD operating systems">List of BSD operating systems</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/GNU" title="GNU">GNU</a>/<a href="http://en.wikipedia.org/wiki/Linux" title="Linux">Linux</a></td> <td><a href="http://en.wikipedia.org/wiki/List_of_Linux_distributions" title="List of Linux distributions">List of Linux distributions</a>, <a href="http://en.wikipedia.org/wiki/Comparison_of_Linux_distributions" title="Comparison of Linux distributions">Comparison of Linux distributions</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Microsoft_Windows" title="Microsoft Windows">Microsoft Windows</a></td> <td><a href="http://en.wikipedia.org/wiki/Windows_95" title="Windows 95">Windows 95</a>, <a href="http://en.wikipedia.org/wiki/Windows_98" title="Windows 98">Windows 98</a>, <a href="http://en.wikipedia.org/wiki/Windows_NT" title="Windows NT">Windows NT</a>, <a href="http://en.wikipedia.org/wiki/Windows_2000" title="Windows 2000">Windows 2000</a>, <a href="http://en.wikipedia.org/wiki/Windows_XP" title="Windows XP">Windows XP</a>, <a href="http://en.wikipedia.org/wiki/Windows_Vista" title="Windows Vista">Windows Vista</a>, <a href="http://en.wikipedia.org/wiki/Windows_CE" title="Windows CE">Windows CE</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/DOS" title="DOS">DOS</a></td> <td><a href="http://en.wikipedia.org/wiki/86-DOS" title="86-DOS">86-DOS</a> (QDOS), <a href="http://en.wikipedia.org/wiki/PC-DOS" title="PC-DOS" class="mw-redirect">PC-DOS</a>, <a href="http://en.wikipedia.org/wiki/MS-DOS" title="MS-DOS">MS-DOS</a>, <a href="http://en.wikipedia.org/wiki/FreeDOS" title="FreeDOS">FreeDOS</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Mac_OS" title="Mac OS">Mac OS</a></td> <td><a href="http://en.wikipedia.org/wiki/Mac_OS" title="Mac OS">Mac OS classic</a>, <a href="http://en.wikipedia.org/wiki/Mac_OS_X" title="Mac OS X">Mac OS X</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Embedded_operating_system" title="Embedded operating system">Embedded</a> and <a href="http://en.wikipedia.org/wiki/Real-time_operating_system" title="Real-time operating system">real-time</a></td> <td><a href="http://en.wikipedia.org/wiki/List_of_operating_systems#Embedded" title="List of operating systems">List of embedded operating systems</a></td> </tr> <tr> <td>Experimental</td> <td><a href="http://en.wikipedia.org/wiki/Amoeba_distributed_operating_system" title="Amoeba distributed operating system">Amoeba</a>, <a href="http://en.wikipedia.org/wiki/Oberon_operating_system" title="Oberon operating system" class="mw-redirect">Oberon</a>/<a href="http://en.wikipedia.org/wiki/Bluebottle_OS" title="Bluebottle OS">Bluebottle</a>, <a href="http://en.wikipedia.org/wiki/Plan_9_from_Bell_Labs" title="Plan 9 from Bell Labs">Plan 9 from Bell Labs</a></td> </tr> <tr> <td rowspan="2"><a href="http://en.wikipedia.org/wiki/Library_%28computing%29" title="Library (computing)">Library</a></td> <td><a href="http://en.wikipedia.org/wiki/Multimedia" title="Multimedia">Multimedia</a></td> <td><a href="http://en.wikipedia.org/wiki/DirectX" title="DirectX">DirectX</a>, <a href="http://en.wikipedia.org/wiki/OpenGL" title="OpenGL">OpenGL</a>, <a href="http://en.wikipedia.org/wiki/OpenAL" title="OpenAL">OpenAL</a></td> </tr> <tr> <td>Programming library</td> <td><a href="http://en.wikipedia.org/wiki/C_standard_library" title="C standard library">C standard library</a>, <a href="http://en.wikipedia.org/wiki/Standard_template_library" title="Standard template library" class="mw-redirect">Standard template library</a></td> </tr> <tr> <td rowspan="2"><a href="http://en.wikipedia.org/wiki/Data_%28computing%29" title="Data (computing)">Data</a></td> <td><a href="http://en.wikipedia.org/wiki/Protocol_%28computing%29" title="Protocol (computing)">Protocol</a></td> <td><a href="http://en.wikipedia.org/wiki/TCP/IP" title="TCP/IP" class="mw-redirect">TCP/IP</a>, <a href="http://en.wikipedia.org/wiki/Kermit_%28protocol%29" title="Kermit (protocol)">Kermit</a>, <a href="http://en.wikipedia.org/wiki/FTP" title="FTP" class="mw-redirect">FTP</a>, <a href="http://en.wikipedia.org/wiki/HTTP" title="HTTP" class="mw-redirect">HTTP</a>, <a href="http://en.wikipedia.org/wiki/SMTP" title="SMTP" class="mw-redirect">SMTP</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/File_format" title="File format">File format</a></td> <td><a href="http://en.wikipedia.org/wiki/HTML" title="HTML">HTML</a>, <a href="http://en.wikipedia.org/wiki/XML" title="XML">XML</a>, <a href="http://en.wikipedia.org/wiki/JPEG" title="JPEG">JPEG</a>, <a href="http://en.wikipedia.org/wiki/MPEG" title="MPEG" class="mw-redirect">MPEG</a>, <a href="http://en.wikipedia.org/wiki/Portable_Network_Graphics" title="Portable Network Graphics">PNG</a></td> </tr> <tr> <td rowspan="2"><a href="http://en.wikipedia.org/wiki/User_interface" title="User interface">User interface</a></td> <td><a href="http://en.wikipedia.org/wiki/Graphical_user_interface" title="Graphical user interface">Graphical user interface</a> (<a href="http://en.wikipedia.org/wiki/WIMP_%28computing%29" title="WIMP (computing)">WIMP</a>)</td> <td><a href="http://en.wikipedia.org/wiki/Microsoft_Windows" title="Microsoft Windows">Microsoft Windows</a>, <a href="http://en.wikipedia.org/wiki/GNOME" title="GNOME">GNOME</a>, <a href="http://en.wikipedia.org/wiki/KDE" title="KDE">KDE</a>, <a href="http://en.wikipedia.org/wiki/QNX" title="QNX">QNX Photon</a>, <a href="http://en.wikipedia.org/wiki/Common_Desktop_Environment" title="Common Desktop Environment">CDE</a>, <a href="http://en.wikipedia.org/wiki/Graphical_Environment_Manager" title="Graphical Environment Manager">GEM</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Text_user_interface" title="Text user interface">Text user interface</a></td> <td><a href="http://en.wikipedia.org/wiki/Command_line_interface" title="Command line interface" class="mw-redirect">Command line interface</a>, <a href="http://en.wikipedia.org/wiki/Shell_%28computing%29" title="Shell (computing)">shells</a></td> </tr> <tr> <td rowspan="9"><a href="http://en.wikipedia.org/wiki/Application_software" title="Application software">Application</a></td> <td><a href="http://en.wikipedia.org/wiki/Office_suite" title="Office suite">Office suite</a></td> <td><a href="http://en.wikipedia.org/wiki/Word_processing" title="Word processing">Word processing</a>, <a href="http://en.wikipedia.org/wiki/Desktop_publishing" title="Desktop publishing">Desktop publishing</a>, <a href="http://en.wikipedia.org/wiki/Presentation_program" title="Presentation program">Presentation program</a>, <a href="http://en.wikipedia.org/wiki/Database_management_system" title="Database management system">Database management system</a>, Scheduling & Time management, <a href="http://en.wikipedia.org/wiki/Spreadsheet" title="Spreadsheet">Spreadsheet</a>, <a href="http://en.wikipedia.org/wiki/Accounting_software" title="Accounting software">Accounting software</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Internet" title="Internet">Internet</a> Access</td> <td><a href="http://en.wikipedia.org/wiki/Web_browser" title="Web browser">Browser</a>, <a href="http://en.wikipedia.org/wiki/E-mail_client" title="E-mail client">E-mail client</a>, <a href="http://en.wikipedia.org/wiki/Web_server" title="Web server">Web server</a>, <a href="http://en.wikipedia.org/wiki/Mail_transfer_agent" title="Mail transfer agent">Mail transfer agent</a>, <a href="http://en.wikipedia.org/wiki/Instant_messaging" title="Instant messaging">Instant messaging</a></td> </tr> <tr> <td>Design and manufacturing</td> <td><a href="http://en.wikipedia.org/wiki/Computer-aided_design" title="Computer-aided design">Computer-aided design</a>, <a href="http://en.wikipedia.org/wiki/Computer-aided_manufacturing" title="Computer-aided manufacturing">Computer-aided manufacturing</a>, Plant management, Robotic manufacturing, Supply chain management</td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Computer_graphics" title="Computer graphics">Graphics</a></td> <td><a href="http://en.wikipedia.org/wiki/Raster_graphics_editor" title="Raster graphics editor">Raster graphics editor</a>, <a href="http://en.wikipedia.org/wiki/Vector_graphics_editor" title="Vector graphics editor">Vector graphics editor</a>, <a href="http://en.wikipedia.org/wiki/3D_modeler" title="3D modeler" class="mw-redirect">3D modeler</a>, <a href="http://en.wikipedia.org/wiki/Animation_software" title="Animation software" class="mw-redirect">Animation editor</a>, <a href="http://en.wikipedia.org/wiki/3D_computer_graphics" title="3D computer graphics">3D computer graphics</a>, <a href="http://en.wikipedia.org/wiki/Video_editing" title="Video editing">Video editing</a>, <a href="http://en.wikipedia.org/wiki/Image_processing" title="Image processing">Image processing</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Digital_audio" title="Digital audio">Audio</a></td> <td><a href="http://en.wikipedia.org/wiki/Digital_audio_editor" title="Digital audio editor">Digital audio editor</a>, <a href="http://en.wikipedia.org/wiki/Audio_player_%28software%29" title="Audio player (software)">Audio playback</a>, Mixing, <a href="http://en.wikipedia.org/wiki/Software_synthesizer" title="Software synthesizer">Audio synthesis</a>, <a href="http://en.wikipedia.org/wiki/Computer_music" title="Computer music">Computer music</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Software_Engineering" title="Software Engineering" class="mw-redirect">Software Engineering</a></td> <td><a href="http://en.wikipedia.org/wiki/Compiler" title="Compiler">Compiler</a>, <a href="http://en.wikipedia.org/wiki/Assembly_language#Assembler" title="Assembly language">Assembler</a>, <a href="http://en.wikipedia.org/wiki/Interpreter_%28computing%29" title="Interpreter (computing)">Interpreter</a>, <a href="http://en.wikipedia.org/wiki/Debugger" title="Debugger">Debugger</a>, <a href="http://en.wikipedia.org/wiki/Text_Editor" title="Text Editor" class="mw-redirect">Text Editor</a>, <a href="http://en.wikipedia.org/wiki/Integrated_development_environment" title="Integrated development environment">Integrated development environment</a>, <a href="http://en.wikipedia.org/wiki/Performance_analysis" title="Performance analysis">Performance analysis</a>, <a href="http://en.wikipedia.org/wiki/Revision_control" title="Revision control">Revision control</a>, <a href="http://en.wikipedia.org/wiki/Software_configuration_management" title="Software configuration management">Software configuration management</a></td> </tr> <tr> <td>Educational</td> <td><a href="http://en.wikipedia.org/wiki/Edutainment" title="Edutainment">Edutainment</a>, <a href="http://en.wikipedia.org/wiki/Educational_game" title="Educational game">Educational game</a>, <a href="http://en.wikipedia.org/wiki/Serious_game" title="Serious game">Serious game</a>, <a href="http://en.wikipedia.org/wiki/Flight_simulator" title="Flight simulator">Flight simulator</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Computer_and_video_games" title="Computer and video games" class="mw-redirect">Games</a></td> <td><a href="http://en.wikipedia.org/wiki/Strategy_game" title="Strategy game">Strategy</a>, Arcade, <a href="http://en.wikipedia.org/wiki/Computer_puzzle_game" title="Computer puzzle game" class="mw-redirect">Puzzle</a>, Simulation, <a href="http://en.wikipedia.org/wiki/First-person_shooter" title="First-person shooter">First-person shooter</a>, <a href="http://en.wikipedia.org/wiki/Platform_game" title="Platform game">Platform</a>, <a href="http://en.wikipedia.org/wiki/Massively_multiplayer_online_game" title="Massively multiplayer online game">Massively multiplayer</a>, <a href="http://en.wikipedia.org/wiki/Interactive_fiction" title="Interactive fiction">Interactive fiction</a></td> </tr> <tr> <td>Misc</td> <td><a href="http://en.wikipedia.org/wiki/Artificial_intelligence" title="Artificial intelligence">Artificial intelligence</a>, <a href="http://en.wikipedia.org/wiki/Antivirus_software" title="Antivirus software">Antivirus software</a>, <a href="http://en.wikipedia.org/wiki/Malware_scanner" title="Malware scanner">Malware scanner</a>, <a href="http://en.wikipedia.org/wiki/Installer" title="Installer" class="mw-redirect">Installer</a>/<a href="http://en.wikipedia.org/wiki/Package_management_system" title="Package management system">Package management systems</a>, <a href="http://en.wikipedia.org/wiki/File_manager" title="File manager">File manager</a></td> </tr> </tbody></table> <p><a name="Programming_languages" id="Programming_languages"></a></p> <h3><span class="mw-headline">Programming languages</span></h3> <p>Programming languages provide various ways of specifying programs for computers to run. Unlike <a href="http://en.wikipedia.org/wiki/Natural_language" title="Natural language">natural languages</a>, programming languages are designed to permit no ambiguity and to be concise. They are purely written languages and are often difficult to read aloud. They are generally either translated into <a href="http://en.wikipedia.org/wiki/Machine_language" title="Machine language" class="mw-redirect">machine language</a> by a <a href="http://en.wikipedia.org/wiki/Compiler" title="Compiler">compiler</a> or an <a href="http://en.wikipedia.org/wiki/Assembly_language#Assembler" title="Assembly language">assembler</a> before being run, or translated directly at run time by an <a href="http://en.wikipedia.org/wiki/Interpreter_%28computing%29" title="Interpreter (computing)">interpreter</a>. Sometimes programs are executed by a hybrid method of the two techniques. There are thousands of different programming languages—some intended to be general purpose, others useful only for highly specialized applications.</p> <table class="wikitable"> <caption><b><a href="http://en.wikipedia.org/wiki/Programming_Languages" title="Programming Languages" class="mw-redirect">Programming Languages</a></b></caption> <tbody><tr> <td rowspan="1">Lists of programming languages</td> <td><a href="http://en.wikipedia.org/wiki/Timeline_of_programming_languages" title="Timeline of programming languages">Timeline of programming languages</a>, <a href="http://en.wikipedia.org/wiki/Categorical_list_of_programming_languages" title="Categorical list of programming languages" class="mw-redirect">Categorical list of programming languages</a>, <a href="http://en.wikipedia.org/wiki/Generational_list_of_programming_languages" title="Generational list of programming languages">Generational list of programming languages</a>, <a href="http://en.wikipedia.org/wiki/Alphabetical_list_of_programming_languages" title="Alphabetical list of programming languages" class="mw-redirect">Alphabetical list of programming languages</a>, <a href="http://en.wikipedia.org/wiki/Non-English-based_programming_languages" title="Non-English-based programming languages">Non-English-based programming languages</a></td> </tr> <tr> <td rowspan="1">Commonly used <a href="http://en.wikipedia.org/wiki/Assembly_language" title="Assembly language">Assembly languages</a></td> <td><a href="http://en.wikipedia.org/wiki/ARM_architecture" title="ARM architecture">ARM</a>, <a href="http://en.wikipedia.org/wiki/MIPS_architecture" title="MIPS architecture">MIPS</a>, <a href="http://en.wikipedia.org/wiki/X86_assembly_language" title="X86 assembly language">x86</a></td> </tr> <tr> <td rowspan="1">Commonly used <a href="http://en.wikipedia.org/wiki/High_level_language" title="High level language" class="mw-redirect">High level languages</a></td> <td><a href="http://en.wikipedia.org/wiki/BASIC" title="BASIC">BASIC</a>, <a href="http://en.wikipedia.org/wiki/C_%28programming_language%29" title="C (programming language)">C</a>, <a href="http://en.wikipedia.org/wiki/C%2B%2B" title="C++">C++</a>, <a href="http://en.wikipedia.org/wiki/C_Sharp_%28programming_language%29" title="C Sharp (programming language)">C#</a>, <a href="http://en.wikipedia.org/wiki/COBOL" title="COBOL">COBOL</a>, <a href="http://en.wikipedia.org/wiki/Fortran" title="Fortran">Fortran</a>, <a href="http://en.wikipedia.org/wiki/Java_%28programming_language%29" title="Java (programming language)">Java</a>, <a href="http://en.wikipedia.org/wiki/Lisp_%28programming_language%29" title="Lisp (programming language)">Lisp</a>, <a href="http://en.wikipedia.org/wiki/Pascal_%28programming_language%29" title="Pascal (programming language)">Pascal</a></td> </tr> <tr> <td rowspan="1">Commonly used <a href="http://en.wikipedia.org/wiki/Scripting_language" title="Scripting language">Scripting languages</a></td> <td><a href="http://en.wikipedia.org/wiki/Bourne_shell" title="Bourne shell">Bourne script</a>, <a href="http://en.wikipedia.org/wiki/JavaScript" title="JavaScript">JavaScript</a>, <a href="http://en.wikipedia.org/wiki/Python_%28programming_language%29" title="Python (programming language)">Python</a>, <a href="http://en.wikipedia.org/wiki/Ruby_%28programming_language%29" title="Ruby (programming language)">Ruby</a>, <a href="http://en.wikipedia.org/wiki/PHP" title="PHP">PHP</a>, <a href="http://en.wikipedia.org/wiki/Perl" title="Perl">Perl</a></td> </tr> </tbody></table> <p><a name="Professions_and_organizations" id="Professions_and_organizations"></a></p> <h3><span class="mw-headline">Professions and organizations</span></h3> <p>As the use of computers has spread throughout society, there are an increasing number of careers involving computers. Following the theme of hardware, software and firmware, the brains of people who work in the industry are sometimes known irreverently as wetware or "meatware".</p> <table class="wikitable"> <caption><b><a href="http://en.wikipedia.org/w/index.php?title=Category:Computer_and_mathematical_occupations&action=edit&redlink=1" class="new" title="Category:Computer and mathematical occupations (page does not exist)">Computer-related professions</a></b></caption> <tbody><tr> <td>Hardware-related</td> <td><a href="http://en.wikipedia.org/wiki/Electrical_engineering" title="Electrical engineering">Electrical engineering</a>, <a href="http://en.wikipedia.org/wiki/Electronics_engineering" title="Electronics engineering" class="mw-redirect">Electronics engineering</a>, <a href="http://en.wikipedia.org/wiki/Computer_engineering" title="Computer engineering">Computer engineering</a>, <a href="http://en.wikipedia.org/wiki/Telecommunications_engineering" title="Telecommunications engineering" class="mw-redirect">Telecommunications engineering</a>, <a href="http://en.wikipedia.org/wiki/Optical_engineering" title="Optical engineering">Optical engineering</a>, <a href="http://en.wikipedia.org/wiki/Nanoscale_engineering" title="Nanoscale engineering" class="mw-redirect">Nanoscale engineering</a></td> </tr> <tr> <td>Software-related</td> <td><a href="http://en.wikipedia.org/wiki/Computer_science" title="Computer science">Computer science</a>, <a href="http://en.wikipedia.org/wiki/Human-computer_interaction" title="Human-computer interaction">Human-computer interaction</a>, <a href="http://en.wikipedia.org/wiki/Information_technology" title="Information technology">Information technology</a>, <a href="http://en.wikipedia.org/wiki/Software_engineering" title="Software engineering">Software engineering</a>, <a href="http://en.wikipedia.org/wiki/Scientific_computing" title="Scientific computing" class="mw-redirect">Scientific computing</a>, <a href="http://en.wikipedia.org/wiki/Web_design" title="Web design">Web design</a>, <a href="http://en.wikipedia.org/wiki/Desktop_publishing" title="Desktop publishing">Desktop publishing</a></td> </tr> </tbody></table> <p>The need for computers to work well together and to be able to exchange information has spawned the need for many standards organizations, clubs and societies of both a formal and informal nature.</p> <table class="wikitable"><caption><b><a href="http://en.wikipedia.org/wiki/Category:Computer-related_organizations" title="Category:Computer-related organizations">Organizations</a></b></caption> <tbody><tr> <td>Standards groups</td> <td><a href="http://en.wikipedia.org/wiki/American_National_Standards_Institute" title="American National Standards Institute">ANSI</a>, <a href="http://en.wikipedia.org/wiki/International_Electrotechnical_Commission" title="International Electrotechnical Commission">IEC</a>, <a href="http://en.wikipedia.org/wiki/Institute_of_Electrical_and_Electronics_Engineers" title="Institute of Electrical and Electronics Engineers">IEEE</a>, <a href="http://en.wikipedia.org/wiki/Internet_Engineering_Task_Force" title="Internet Engineering Task Force">IETF</a>, <a href="http://en.wikipedia.org/wiki/International_Organization_for_Standardization" title="International Organization for Standardization">ISO</a>, <a href="http://en.wikipedia.org/wiki/World_Wide_Web_Consortium" title="World Wide Web Consortium">W3C</a></td> </tr> <tr> <td>Professional Societies</td> <td><a href="http://en.wikipedia.org/wiki/Association_for_Computing_Machinery" title="Association for Computing Machinery">ACM</a>, <a href="http://en.wikipedia.org/wiki/Category:Association_for_Computing_Machinery_Special_Interest_Groups" title="Category:Association for Computing Machinery Special Interest Groups">ACM Special Interest Groups</a>, <a href="http://en.wikipedia.org/wiki/Institution_of_Engineering_and_Technology" title="Institution of Engineering and Technology">IET</a>, <a href="http://en.wikipedia.org/wiki/IFIP" title="IFIP" class="mw-redirect">IFIP</a></td> </tr> <tr> <td><a href="http://en.wikipedia.org/wiki/Free_software" title="Free software">Free</a>/<a href="http://en.wikipedia.org/wiki/Open-source_software" title="Open-source software" class="mw-redirect">Open source</a> software groups</td> <td><a href="http://en.wikipedia.org/wiki/Free_Software_Foundation" title="Free Software Foundation">Free Software Foundation</a>, <a href="http://en.wikipedia.org/wiki/Mozilla_Foundation" title="Mozilla Foundation">Mozilla Foundation</a>, <a href="http://en.wikipedia.org/wiki/Apache_Software_Foundation" title="Apache Software Foundation">Apache Software Foundation</a></td></tr></tbody></table>Chathuranga and Menakahttp://www.blogger.com/profile/02083506018847115451noreply@blogger.com0tag:blogger.com,1999:blog-1458402158713757479.post-53869075235952664492008-10-10T10:32:00.000-07:002008-10-10T10:38:15.008-07:00Networking and the Internet<h3><span class="mw-headline">Networking and the Internet</span></h3> <table class="metadata plainlinks ambox ambox-content" style=""> <tbody><tr> <td class="mbox-image"> <div style="width: 52px;"><a href="http://en.wikipedia.org/wiki/Image:Question_book-new.svg" class="image" title="Question book-new.svg"><img alt="" src="http://upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" border="0" height="39" width="50" /></a></div> </td> <td class="mbox-text" style=""><b>This section does not <a href="http://en.wikipedia.org/wiki/Wikipedia:Citing_sources" title="Wikipedia:Citing sources">cite</a> any <a href="http://en.wikipedia.org/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">references or sources</a>.</b><br /><small class="plainlinks">Please help <a href="http://en.wikipedia.org/w/index.php?title=Computer&action=edit" class="external text" title="http://en.wikipedia.org/w/index.php?title=Computer&action=edit" rel="nofollow">improve this section</a> by adding citations to <a href="http://en.wikipedia.org/wiki/Wikipedia:Reliable_sources" title="Wikipedia:Reliable sources">reliable sources</a>. <a href="http://en.wikipedia.org/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">Unverifiable</a> material may be challenged and removed. <i>(July 2008)</i></small></td> </tr> </tbody></table> <dl><dd> <div class="noprint relarticle mainarticle"><i>Main articles: <a href="http://en.wikipedia.org/wiki/Computer_networking" title="Computer networking">Computer networking</a> and <a href="http://en.wikipedia.org/wiki/Internet" title="Internet">Internet</a></i></div> </dd></dl> <div class="thumb tleft"> <div class="thumbinner" style="width: 302px;"><a href="http://en.wikipedia.org/wiki/Image:Internet_map_1024.jpg" class="image" title="Visualization of a portion of the routes on the Internet."><img alt="Visualization of a portion of the routes on the Internet." src="http://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/Internet_map_1024.jpg/300px-Internet_map_1024.jpg" class="thumbimage" border="0" height="300" width="300" /></a> <div class="thumbcaption"> <div class="magnify"><a href="http://en.wikipedia.org/wiki/Image:Internet_map_1024.jpg" class="internal" title="Enlarge"><img src="http://en.wikipedia.org/skins-1.5/common/images/magnify-clip.png" alt="" height="11" width="15" /></a></div> Visualization of a portion of the <a href="http://en.wikipedia.org/wiki/Routing" title="Routing">routes</a> on the Internet.</div> </div> </div> <p>Computers have been used to coordinate information between multiple locations since the 1950s. The U.S. military's <a href="http://en.wikipedia.org/wiki/Semi_Automatic_Ground_Environment" title="Semi Automatic Ground Environment">SAGE</a> system was the first large-scale example of such a system, which led to a number of special-purpose commercial systems like <a href="http://en.wikipedia.org/wiki/Sabre_%28computer_system%29" title="Sabre (computer system)">Sabre</a>.</p> In the 1970s, computer engineers at research institutions throughout the United States began to link their computers together using telecommunications technology. This effort was funded by ARPA (now <a href="http://en.wikipedia.org/wiki/DARPA" title="DARPA">DARPA</a>), and the <a href="http://en.wikipedia.org/wiki/Computer_network" title="Computer network">computer network</a> that it produced was called the <a href="http://en.wikipedia.org/wiki/Advanced_Research_Projects_Agency_Network" title="Advanced Research Projects Agency Network" class="mw-redirect">ARPANET</a>. The technologies that made the Arpanet possible spread and evolved. In time, the network spread beyond academic and military institutions and became known as the <a href="http://en.wikipedia.org/wiki/Internet" title="Internet">Internet</a>. The emergence of networking involved a redefinition of the nature and boundaries of the computer. Computer operating systems and applications were modified to include the ability to define and access the resources of other computers on the network, such as peripheral devices, stored information, and the like, as extensions of the resources of an individual computer. Initially these facilities were available primarily to people working in high-tech environments, but in the 1990s the spread of applications like <a href="http://en.wikipedia.org/wiki/E-mail" title="E-mail">e-mail</a> and the <a href="http://en.wikipedia.org/wiki/World_Wide_Web" title="World Wide Web">World Wide Web</a>, combined with the development of cheap, fast networking technologies like <a href="http://en.wikipedia.org/wiki/Ethernet" title="Ethernet">Ethernet</a> and <a href="http://en.wikipedia.org/wiki/ADSL" title="ADSL" class="mw-redirect">ADSL</a> saw computer networking become almost ubiquitous. In fact, the number of computers that are networked is growing phenomenally. A very large proportion of <a href="http://en.wikipedia.org/wiki/Personal_computers" title="Personal computers" class="mw-redirect">personal computers</a> regularly connect to the <a href="http://en.wikipedia.org/wiki/Internet" title="Internet">Internet</a> to communicate and receive information. "Wireless" networking, often utilizing <a href="http://en.wikipedia.org/wiki/Mobile_phone" title="Mobile phone">mobile phone</a> networks, has meant networking is becoming increasingly ubiquitous even in mobile computing environments.Chathuranga and Menakahttp://www.blogger.com/profile/02083506018847115451noreply@blogger.com0