Slide 1

Introduction to Computer

1ContentsWhat is a ComputerCharacteristics of ComputerHistory of ComputerGenerations of ComputerClassification of ComputersComputer SystemInput-Process-Output ConceptComponents of Computer HardwareApplication of Computers

vikrantjaswal@gmail.com10/17/20132Computer Fundamentals by Dr. Anita GoelWhat is a ComputerComputer is an electronic device that accepts data as input, processes the input data by performing mathematical and logical operations on it, and gives the desired output. Two categoriesDigital ComputerAnalog Computer

10/17/2013vikrantjaswal@gmail.com3Computer Fundamentals by Dr. Anita GoelCharacteristics of ComputerSpeed AccuracyDiligenceStorage capabilityVersatilityAutomation 10/17/2013vikrantjaswal@gmail.com4Computer Fundamentals by Dr. Anita GoelHistory of ComputerCalculating machines ABACUSNapiers BoneSlide RulePascals Adding and Subtraction MachineLeibnizs Multiplication and Dividing Machine Punch card system Babbages Analytical Engine Holleriths punched card tabulating machine 10/17/2013vikrantjaswal@gmail.com5

Computer Fundamentals by Dr. Anita GoelGenerations of ComputerEvolution of computer to the current stateFive generationsCategorized on the basis of Technology used by them (hardware and software) Computing characteristics (speed - number of instructions executed per second) Physical appearance Their applications

10/17/2013vikrantjaswal@gmail.com6Computer Fundamentals by Dr. Anita GoelGenerations of Computer10/17/2013vikrantjaswal@gmail.com7Computer Fundamentals by Dr. Anita GoelFirst Generation: 1940-56Vacuum tubes, magnetic drums, punched cards, paper tapes and printoutsMachine language Computation time in milliseconds Enormous in sizeFor scientific applications Examples UNIVersal Automatic Computer (UNIVAC)Electronic Numerical Integrator And Calculator (ENIAC)Electronic Discrete Variable Automatic Computer (EDVAC)vikrantjaswal@gmail.com

Punched Card

UNIVAC10/17/20138Computer Fundamentals by Dr. Anita GoelFirst Generation: 1940-56vikrantjaswal@gmail.com

Time magazine ran the cover story "The Brain Builders" on Tom Watson, Jr., and IBM on March 28, 1955. IBM had just installed a model 702 Electronic Data Processing Machine in its Monsanto HQ in St. Louis, called "the giant brain." It had 2,500 tubes, did 7,200 logical operations per sec., with punch card and magnetic tape storage. It was the result of IBM slogan "Think" and Tom Watson, Jr., who took over presidency of IBM in 1952, and who led the battle to automate American business. IBM had orders for 14 model 702s at a monthly rental of $20,000, and had delivered 19 of the earlier model 701. The AEC had 3 model 701 machines, the Weather Bureau had one model 701. IBM had just delivered the NORC computer to the Navy, and had 109 orders for the new 704 and 705 models that will cost IBM $1 million each to build. Source: http://history.sandiego.edu/GEN/recording/watson.html10/17/20139Computer Fundamentals by Dr. Anita GoelSecond Generation: 1956-1963Transistors, magnetic core technology , magnetic tapes and magnetic disks, concept of a stored program Assembly language Computation time in microseconds. Reduced size compared to first generation computersCost of commercial production was very highExamplesPDP-8IBM 1401CDC 1604vikrantjaswal@gmail.com

10/17/201310Computer Fundamentals by Dr. Anita GoelThird Generation: 1964-1971Integrated Circuit (IC) chips, keyboard, MonitorOperating system, High-level languagesComputation time in nanosecondsQuite small compared to second generation computers Accessible to mass audience Produced commerciallyExamples IBM 370 PDP 11

vikrantjaswal@gmail.com

DEC PDP 1110/17/201311Computer Fundamentals by Dr. Anita GoelFourth Generation: 1971-PresentLSI, VLSI, Microprocessor, PC, Semiconductor Memory, Linking of computers, Mouse and Handheld DevicesGUI, OS like MS-DOS and MS-WindowsHigh-Level Programming LanguagesComputation time in picosecondsSmaller than computers of previous generationWidely available for commercial purposesPC for home userExamplesIntel 4004 chip was the first MicroprocessorIBM, Apples Macintosh vikrantjaswal@gmail.com

10/17/201312Computer Fundamentals by Dr. Anita GoelFifth Generation: Present & NextUsing Artificial Intelligence (AI) Expert Systems (ES), Neuro Linguistic Programming (NLP), Speech recognition, Voice recognition, Robotics etc.

Capable of learning and self organization

SLSI (Super-Large Scale Integration), large memory

Parallel processing

vikrantjaswal@gmail.com10/17/201313Computer Fundamentals by Dr. Anita Goel10/17/2013vikrantjaswal@gmail.com14FirstGenerationSecondGenerationThirdGenerationFourthGenerationFifthGenerationVacuumTubesSolid-StateIntegratedCircuitsLSI, VLSIMicro-processorsGreaterPower,SmallerFootprintTrend: Toward Smaller, Faster, More Reliable, and Less CostlyTrend: Toward Easy to Purchase, and Easy to MaintainComputer Fundamentals by Dr. Anita GoelClassification of ComputersCategories based on Size Type CategoriesMicrocomputersMinicomputersMainframe computersSupercomputer

vikrantjaswal@gmail.com10/17/201315Computer Fundamentals by Dr. Anita GoelClassification of ComputersCategories based on Size Type CategoriesMicrocomputersMinicomputersMainframe computersSupercomputer

10/17/2013vikrantjaswal@gmail.com16Computer Fundamentals by Dr. Anita GoelMicrocomputerSmall, low-cost, single-user digital computer. IncludeDesktop computer or PC: Stand-alone machine, not very expensive, for single user. Manufacturers: Apple, Microsoft, HP, Dell, Lenovo, Notebook or laptop: Portable , small size, costlier than desktopNetbook: Smaller notebooks, low weight, low cost, for web-based applications.Tablet computer: Input via stylus or pen, Portable Handheld computer or PDA: Held on top of palm, small in size, uses pen or stylus, limited memory, less powerful. Smart phones: Cellular phones (function both as phone and small PC), to access e-mail, download music, play games etc. Manufacturers: Blackberry, Apple, HTC, Nokia, LG, Motorolavikrantjaswal@gmail.com10/17/201317Computer Fundamentals by Dr. Anita GoelMinicomputersMulti-user systems. High processing speed High storage capacity than the microcomputers. Support 4 to 200 users simultaneously. ExamplesPDP 11IBM (8000 series)

vikrantjaswal@gmail.com10/17/201318Computer Fundamentals by Dr. Anita GoelMainframe computersMulti-user, multi-programming , high-performance computers. Very high speed, large storage capacity Used in centralized databases. Access via dumb terminal, an intelligent terminal, or PC. Dumb terminal: No own data storage & processing. Has I/O device only. Intelligent terminal: Has the I/O device, can do processing, but, cannot store data of its own. Use processing power and storage facility of mainframes Examples CDC 6600IBM ES000 series.vikrantjaswal@gmail.com10/17/201319Computer Fundamentals by Dr. Anita GoelSupercomputersFastest and the most expensive machines. High processing speedSpeed in FLOPS (FLoating point Operations Per Second). Used for highly calculation-intensive tasks - weather forecasting, climate research, molecular research, biological research, nuclear researchExamplesIBM Roadrunner, IBM Blue geneIntel ASCI red. PARAM in Indiavikrantjaswal@gmail.com10/17/201320Computer Fundamentals by Dr. Anita GoelComputer SystemFour partsHardware: Mechanical parts of computer, e.g. Keyboard, monitor, hard disk drive etc.Software: Set of instructions (Program) and documentation. Instructs the computer about the task to be performed. Data - Isolated values or raw facts.Provided as input to computer for processing Users -People who write computer programs or interact with computer.vikrantjaswal@gmail.com10/17/201321Computer Fundamentals by Dr. Anita GoelApplication of Computers vikrantjaswal@gmail.com

10/17/201322Computer Fundamentals by Dr. Anita GoelComponents -Computer HardwareThree main components I/O Unit - user interacts with computer via I/O unit Input unit accepts data from the user (Devices - keyboard, trackball, mouse)Output unit provides processed data to user (Devices - monitor and printer)CPU - Controls, coordinates , supervises operations of computer. Arithmetic Logic Unit (ALU) - performs arithmetic and logic operations on input data. Control Unit (CU) - controls overall operations of computerRegisters - temporary storage of data, instructions, addresses, intermediate results Memory Unit Stores data, instructions etc.Main memory or Primary memory - Stores data, instructions, intermediate results ,output, temporarily Secondary memory Stores data, programs, output permanentlyMagnetic disks, optical disks and magnetic tapes vikrantjaswal@gmail.com10/17/201323Computer Fundamentals by Dr. Anita Goel10/17/2013vikrantjaswal@gmail.com24

Computer Fundamentals by Dr. Anita GoelComponents of Computer Hardware/Block Diagram vikrantjaswal@gmail.comCPURegisters Control UnitArithmetic and Logic UnitInput UnitOutput UnitMemory Unit10/17/201325Computer Fundamentals by Dr. Anita GoelCentral Processing Unit ALU, Registers, CUMemory Unit Cache, Primary, Secondary MemoryChapter-2: Computer System Hardware26Computer Fundamentals by Dr. Anita GoelCentral Processing UnitCPU or processor - brain of computerParts - ALU, CU, Registers Executes stored program instructions, i.e. instructions and data stored in memory before execution ProcessingGets data and instructions from memoryInterprets instructions and perform operationSends processed data or result to memory Fabricated as IC chip - microprocessorMicroprocessor plugged into Motherboard Motherboard: A circuit board with electronic circuit etched on it and connects microprocessor with other hardware componentsChapter-2: Computer System Hardware27Computer Fundamentals by Dr. Anita GoelALUTwo units arithmetic unit and logic unit. Arithmetic unit Performs arithmetic operations on the data E.g. addition, subtraction, multiplication, division Logic unit Performs logic operations. E.g. greater than, less than or equal to condition Uses registers to hold data being processed.Chapter-2: Computer System Hardware28Computer Fundamentals by Dr. Anita GoelRegistersHigh speed storage areas, least storage capacity, directly accessed & manipulated by CPU during instruction execution CPUs working memorySome registers: ACC (accumulator): stores the result of arithmetic and logic operation.IR (instruction register): contain the current instruction most recently fetched.PC (Program counter): contains the address of next instruction to be processed.MAR (memory address register): contain the address of next location in the memory to be accessed.MBR (memory buffer register): temporarily stores data from memory or the data to be sent to memory.DR (data register): stores the operands and any other data.Number of registers: Ten to hundreds Depends on type & complexity of processorSize of register (word size)8, 16, 32, 64 bitsNowadays, PCs have 64-bit registersChapter-2: Computer System Hardware29Computer Fundamentals by Dr. Anita GoelControl UnitOrganizes processing of data & instructionsTells when to fetch data & instructions, what to do, where to store results, sequencing of events during processing etc.Acts as a supervisorControls and coordinates activity of other units Does not do actual processing of dataCoordinates I/O devicesHolds CPUs Instruction Set (list of all operations that CPU can perform) Chapter-2: Computer System Hardware30Computer Fundamentals by Dr. Anita GoelMemory UnitCache MemoryPrimary or Main memorySecondary memoryChapter-2: Computer System Hardware31Computer Fundamentals by Dr. Anita GoelCache MemoryVery high speed memory in between RAM & CPU Increases speed of processing CPU first checks cache for data. If data is not found in cache, then looks for it in RAMCacheBuilt-in Level 1 (L1) cache & Level 2 (L2) cache. Separate chip on motherboard for Level 3 (L3) cache CPUs have 256KB L1 cache & 2MB of L2 cache Very expensive, so smaller in size. Chapter-2: Computer System Hardware32Computer Fundamentals by Dr. Anita GoelPrimary MemoryMain memory of computer. Semiconductor memory.Stores data & instructions during processing of dataTwo kinds - RAM and ROMRAM Volatile - temporary storage for data & instructionsStores input data, before processing; output data before sending to output device; intermediate resultsLimited storage capacity, due to its high costROM Non-volatile, read only memory. Permanent storageStores standard processing programs that permanently reside in computerComes programmed by manufacturerChapter-2: Computer System Hardware33Computer Fundamentals by Dr. Anita GoelSecondary MemoryStores data & instructions permanently Non-volatile memoryProvides back-up storage for data & instructions High storage capacity. Cheaper than primary memory Takes longer time to access data & instructions, than the primary memory E.g. Magnetic tape drive, floppy drive, disk drive, optical disk drive

Chapter-2: Computer System Hardware34Computer Fundamentals by Dr. Anita GoelInteraction between CPU and MemoryChapter-2: Computer System Hardware35Data BusControl BusAddress BusCPUMemorySystem BusComputer Fundamentals by Dr. Anita Goel