Text1ComponentsofComputerPassageAAcomputersystemincludeshardwareandsoftware.Hardwareconsistsofinput,processingandoutputdevices.Softwarereferstoprograms.First,weintroducehardware.Thebasicinputdeviceofacomputersystemiskey

　　Text1ComponentsofComputer

　　PassageA

　　Acomputersystemincludeshardwareandsoftware.Hardwareconsistsofinput,processingandoutputdevices.Softwarereferstoprograms.

　　First,weintroducehardware.Thebasicinputdeviceofacomputersystemiskeyboard.Mouseisinputdevice,too.Keyboardinputsdataorprogramsintothecomputer.Theprocessingdeviceexecutesandstoresprogramsanddata.Display,anoutputdeviceofthecomputer,servesasawindowontheprocessingdevice.Itallowsuserstoviewitscontents.Printerisalsoanoutputdeviceofthecomputer.

　　Secondly,weintroduceprograms.Programconsistsofmanyinstructions.Programmersorcomputerusersusethemtotellcomputerswhattodo.OneofthebasicprogramsisDiskOperatingSystem,wecallitDOS.

　　PassageB

　　Astandardkeyboardmainlyconsistsofthreefunctionalgroups.Theyaretypewritercharacterkeys,numerickeypadandspecialfunctionalkeys.

　　Inthemiddleofthekeyboard,therearetypewritercharacterkeys.Theirfunctionsarelikethoseofanordinarytypewriter.Thenumerickeypadisontherightoftypewritercharacterkeys.Therearefunctionalkeysonthefirstlineofthekeyboard.Theybelongtospecialfunctionalkeys.

　　Therearealsothreeimportantspecialfunctionalkeysonthekeyboard.TheyareEsc(Escape),Ctrl(Control)andAlt(Alternate).Ifyouwanttoknowmoreinformation,youcanfindtheminyouruser’smanual.