milestones in the history of computers

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1、MilestonesintheHistoryofComputersBelowisalistoffamouspeopleandcomputersinthehistoryofcomputing.Thelistisdividedintofivecategoriesorgenerationsbasedonthetypeoftechnologyusedintheconstructionofthecomputersorcomputingdevices.0thGeneration-Mechanical&Electro-mech

2、anicalUpuntiltheoutbreakoftheSecondWorldWar,computingdevicesweremechanicalorelectro-mechanical.Thefirst"known"mechanicalcalculator(asidefromtheabacus)wasWilhelmSchickard's"CalculatingClock"(1623).Thisdevicewaslostearlyonsoformanyyearsitwasbelievedthatacalcula

3、torinventedbyBlaisePascalin1642wasthefirstmechanicalcalculator.Pascal'sPascalinecouldonlyaddandsubtractandalthoughPascaltriedtomarkethisinvention,itshighcostandtechnicalunreliabilitydidnotmakeita"bestseller".GottfriedWilhelmvonLeibnizalsoinventedacalculator,o

4、nethatcouldalsomultiply(usingrepeatedaddition).Again,thetechnologyofthetimedidnotmakeforareliabledevicealthoughLiebniz'sideaswerebasicallysound.CharliesBabbage,a19thcentury"polymath"devisedacalculatingmachine,theDifferenceEngineI(1823)whichcouldbeusedtomechan

5、icallygeneratemathematicaltables.HeevenobtainedfundingfromtheBritishgovernmenttobuildit.Unfortunately,themachinewasnevercompletedpartlybecauseofthetechnologicaldifficultiesinherentinconstructingsocomplexamechanicaldeviceandperhapspartlyduetoBabbage'sbecomingi

6、nterestedinbuildingamoreambitiouscalculatingmachine,theAnalyticEngine(alsoneverconstructed).TheAnalyticEnginewasessentiallyageneralpurpose-calculatingdevice.Ithada"store"whichcouldstorenumbersanda"mill"whichwouldperformasequenceofcalculations.Afriendofhis,Aug

7、ustaAdaByron,latertheCountessofLovelace,becameinterestedinBabbage'sworkanddidmuchtopopularizehisdevice.Sheevenwrotea"program"fortheAnalyticEngineandthussheisconsideredtobethefirstcomputerprogrammer.MechanicalCalculators1."CalculatingClock"(1623)-WilhelmSchick

8、ard2.Pascaline(1642)-BlaisePascal(1623-1662)3.GottfriedWilhelmvonLeibniz(1646-1716)4.CharlesBabbage(1792-1871)oDifferenceEngineI(1823)&IIoAnalyticEngine(1833)§TheAnalyticEngineWebSiteatht