Slide 1What is a Computer?What is a Computer? (cont.)Slide 4Moore's LawSlide 6Moore's Law and PerformanceSlide 8Slide 9Computer OrganizationComputer Organization (cont.)Slide 12Slide 13Slide 14Slide 15Operation System (OS)Application SoftwareProgramming LanguagesProgramming Languages (cont.)Slide 20Slide 21Semantic GapC Programming LanguageThe C Standard LibraryThe C Standard Library (cont.)Slide 26A Typical C Program Development EnvironmentSlide 28Constructs in C LanguageAcknowledgementsDepartment of Computer and Information Science,School of Science, IUPUIDale Roberts, LecturerComputer Science, IUPUIE-mail: [email protected] 230Computer ArchitectureWhat is a Computer?What is a Computer?ComputerComputerDevice capable of performing computations and making Device capable of performing computations and making logical decisionslogical decisionsComputers process data under the control of sets of Computers process data under the control of sets of instructions called computer programsinstructions called computer programsPersonal computersPersonal computers: economical enough for individual: economical enough for individualDistributed computingDistributed computing: computing distributed over : computing distributed over networksnetworksClient/server computingClient/server computing: sharing of information across : sharing of information across computer networks between file servers and clients computer networks between file servers and clients (personal computers) (personal computers) Dale RobertsWhat is a Computer? What is a Computer? (cont.)(cont.)Computer HardwareComputer Hardware Various devices comprising a computer: Various devices comprising a computer: Keyboard, screen, mouse, disks, memory, CD-Keyboard, screen, mouse, disks, memory, CD-ROM, and processing unitsROM, and processing unitsHardware Trends: every year or two the following Hardware Trends: every year or two the following approximately double (Moore’s Law):approximately double (Moore’s Law):Amount of memory in which to execute programsAmount of memory in which to execute programsAmount of secondary storage (such as disk storage)Amount of secondary storage (such as disk storage)Used to hold programs and data over the longer termUsed to hold programs and data over the longer termProcessor speedsProcessor speedsThe speeds at which computers execute their programsThe speeds at which computers execute their programsHigh-levelLanguageAssemblyLanguageFirmwareMachineCodeHardwareUserApplicationSoftwareOSWhat is a Computer? What is a Computer? (cont.)(cont.)Computer SoftwareComputer Software Computer Programs that run on a computer, includingComputer Programs that run on a computer, includingOperation System (OS)Operation System (OS)Application SoftwareApplication SoftwareComputer LanguageComputer LanguageHigh-levelLanguageAssemblyLanguageFirmwareMachineCodeHardwareUserApplicationSoftwareOSMoore's LawMoore's LawDefined by Defined by Dr. Gordon Moore Dr. Gordon Moore during the during the sixties.sixties.Predicts an exponential increase in Predicts an exponential increase in component density over time, with a component density over time, with a doubling time of 18 months.doubling time of 18 months.Applicable to microprocessors, DRAMs , Applicable to microprocessors, DRAMs , DSPs and other microelectronics.DSPs and other microelectronics.Monotonic increase in density observed Monotonic increase in density observed since the 1960s.since the 1960s.Moore’s Law - DensityMoore’s Law - DensityMoore's Law and PerformanceMoore's Law and PerformanceThe performance of computers is The performance of computers is determined by architecture and clock determined by architecture and clock speed.speed.Clock speed doubles over a 3 year period Clock speed doubles over a 3 year period due to the scaling laws on chip.due to the scaling laws on chip.Processors using identical or similar Processors using identical or similar architectures gain performance directly as architectures gain performance directly as a function of Moore's Law.a function of Moore's Law.Improvements in internal architecture can Improvements in internal architecture can yield better gains than predicted by yield better gains than predicted by Moore's Law.Moore's Law.Moore’s Law - Clock SpeedMoore’s Law - Clock SpeedWhat is a Computer? What is a Computer? (cont.)(cont.)InternetInternetThe Internet enablesThe Internet enablesQuick and easy communication via e-mailQuick and easy communication via e-mailInternational networking of computersInternational networking of computersPacket switchingPacket switchingThe transfer of digital data via small packetsThe transfer of digital data via small packetsAllows multiple users to send and receive data simultaneouslyAllows multiple users to send and receive data simultaneouslyNo centralized controlNo centralized controlIf one part of the Internet fails, other parts can still operateIf one part of the Internet fails, other parts can still operateBandwidth Bandwidth Information carrying capacity of communications linesInformation carrying capacity of communications linesEx: Internet T2 at IUPUIEx: Internet T2 at IUPUIWorld Wide WebWorld Wide Web Locate and view multimedia-based documents on almost any subjectLocate and view multimedia-based documents on almost any subjectMakes information instantly and conveniently accessible worldwideMakes information instantly and conveniently accessible worldwidePossible for individuals and small businesses to get worldwide exposurePossible for individuals and small businesses to get worldwide exposureChanging the way business is done Changing the way business is doneComputer OrganizationComputer OrganizationA Typical Von-Neumann ArchitectureA Typical Von-Neumann ArchitectureExample:Example:1.1.InputInput unit unit2.2.OutputOutput unit unit 3.3.MemoryMemory unit unit 4.4.Arithmetic and logicArithmetic and logic unit (ALU) unit (ALU) 5.5.Central processingCentral processing unit (CPU) unit (CPU) 6.6.Secondary storageSecondary storage unit unit Control Circuit(ex: PC: Program Counter)ALUMemory I/OCPUComputer Organization Computer Organization (cont.)(cont.)Six logical units in every computer:Six logical units in every computer:1.1.InputInput unit unitObtains information from input devices (keyboard, mouse)Obtains information from input devices (keyboard, mouse)2.2.OutputOutput unit unit Outputs information (to screen, to printer, to control other Outputs information (to