计算机应用基础(双语)课件PPTCha.pptx
Chapter 1,Computer Hardware,1,Whats inside?,In this chapter,you will:Gain an overview of computer equipment and terminologyLearn how computers are classified Learn how personal computers fit into the gamut of machines from PDAs to supercomputersReview basic components of a typical personal computer systemLook inside the system unitExplore advantages and disadvantages of several computer storage devicesLearn some basics about maintaining your computer and troubleshooting problems,2,Practical Computer Literacy,3rd Edition,What is a computer?,A device that:Accepts inputProcesses dataStores dataProduces output,3,Practical Computer Literacy,3rd Edition,What is a computer?,Computer input is whatever is typed,submitted,or transmitted to a computer systemData refers to symbols that represent facts,objects,and ideasProcessing is manipulation of dataMost takes place in central processing unit(CPU),a computers“brain”Computer programs are instructions that tell computers how to process,4,Practical Computer Literacy,3rd Edition,What is a computer?,An operating system is software that helps a computer operate efficiently and keep track of dataApplication software helps users“apply”computers to specific tasksMemory is temporary storageStorage is permanent Computer output is results produced by computer,5,Practical Computer Literacy,3rd Edition,What is a computer?,6,Practical Computer Literacy,3rd Edition,How are computers classified?,Computers are divided into five categories:Handheld computersPersonal computersServersMainframe computersSupercomputers,7,Practical Computer Literacy,3rd Edition,How are computers classified?,Handheld computer(PDA)features include:Small keyboard or touch-sensitive screen Designed to fit in your pocketRuns on batteriesUsed while holding it,8,Practical Computer Literacy,3rd Edition,How are computers classified?,A personal computer is designed to meet the computing needs of an individualDesktop computers fit on desks and run on power from wall outletsA Notebook computer(laptop)incorporates screen,keyboard,storage,and processing,9,Practical Computer Literacy,3rd Edition,How are computers classified?,10,A tablet computer is portable,featuring a touch-sensitive screen used for writing or drawing,A server is used to serve data to computers connected to a network,Practical Computer Literacy,3rd Edition,A mainframe computer is capable of simultaneously processing data for hundreds or thousands of usersA supercomputer is one of the fastest computers in the world and can tackle complex tasks,How are computers classified?,11,Practical Computer Literacy,3rd Edition,Can computers connect to each other?,A PDA can connect to desktop with a cable or wireless linkPersonal computers can connect to each other or larger computers via wired or wireless computer networksA computer network can be as few as two or as many as thousands of computersThe Internet is the worlds largest network,connecting millions of computers,12,Practical Computer Literacy,3rd Edition,Can computers connect to each other?,Computers can be connected using a centralized model or a distributed modelA Centralized computing system depends on a centrally-located computer for processing and storageA distributed computer network spreads the processing and storage tasks among many computers,13,Practical Computer Literacy,3rd Edition,14,Centralized computer system,Distributed computer network,Practical Computer Literacy,3rd Edition,Can computers connect to each other?,Can computers connect to each other?,Large-scale centralized and distributed computer systems are used for many tasks:Government applications include tax rolls,census records,and vehicle registrationCommercial applications include inventory,payroll,and point-of-saleHospital and healthcare organizations applications include patient records,integrated diagnostic tools,patient billing,and health insurance claims processingIn education,applications include course registration,student records,budgeting,and payroll,15,Practical Computer Literacy,3rd Edition,What are the components of a personal computer system?,Included in a typical personal computer system are:System unitDisplay deviceKeyboardMouse/TrackpadStorage devicesMemory card slotsUSB portsSound card and speakersWebcamNetwork circuitryPrinter,16,Practical Computer Literacy,3rd Edition,What are the components of a personal computer system?,17,Practical Computer Literacy,3rd Edition,Whats inside the system unit?,The System contains storage devices,a power supply,and main circuit board(motherboard)“Computer chip”,“microchip”,and“chip”are technical jargon for an integrated circuitAn integrated circuit is a super-thin slice of semi-conducting material packed with microscopic circuit elementsA microprocessor is an integrated circuit designed to process instructions.,18,Practical Computer Literacy,3rd Edition,Whats inside the system unit?,19,Practical Computer Literacy,3rd Edition,How do computer circuits manipulate data?,Most computers are electronic,digital devicesDigital devices work with discrete data,such as digits 1 and 0,or like a light switch on or offAnalog devices work with continuous data,like a dimmer switch with continuous range,20,Practical Computer Literacy,3rd Edition,How do computer circuits manipulate data?,Most computers use simplest technology of two possible states,like on-off switchUsually we indicate“on”state as 1 and“off”state as 0These 1s and 0s are referred to as binary digits or shortened to bitsComputers use sequences of bits to digitally represent numbers,letters,punctuation marks,music,pictures,and videos,21,Practical Computer Literacy,3rd Edition,How do computer circuits manipulate data?,Computers employ several codes to represent character data,including:ASCII requires only seven bits for each characterExtended ASCII requires eight bits for each characterEBCDIC is eight-bit technology used on older,IBM mainframe computersUnicode uses sixteen bits and provides code for 65,000 characters,22,Practical Computer Literacy,3rd Edition,23,Practical Computer Literacy,3rd Edition,How do computer circuits manipulate data?,What factors affect computer speed,power and compatibility?,Computers have three major components:Processor MemoryStorageWhen a program is started,it is moved from storage to memory The processor fetches program instructions from memory,then begins to execute,24,Practical Computer Literacy,3rd Edition,If instructions require data,the processor fetches it from storage,loads it into memory,then transfers it to the microprocessorThe results are sent back to memoryThe results can be stored or sent to output printer or screen,25,Practical Computer Literacy,3rd Edition,What factors affect computer speed,power and compatibility?,Speed and efficiency of processing cycle can be affected by factors such as:Microprocessor type and speedMemory capacityHard disk drive speed and organizationDisplay capability and video memoryNetwork and modem connection speed,26,Practical Computer Literacy,3rd Edition,What factors affect computer speed,power and compatibility?,What factors affect speed,power and compatibility?,Bit is abbreviated as lowercase“b”Byte is composed of eight bits and is abbreviated by uppercase“B”These abbreviations combined with kilo produce specifications such as KB(kilobyte)and Kb(kilobit),27,Practical Computer Literacy,3rd Edition,What factors affect speed,power and compatibility?,In world of computers kilo means 1024,not 1000Kilobit is 1024 bits and kilobyte is 1024 bytesKilobytes is often used when referring to size of small computer files,28,Practical Computer Literacy,3rd Edition,What factors affect speed,power and compatibility?,Prefix“mega”means a million,or in context of bits and bytes,1,048,576Megabits is used when referring to speed of data transmissionMegabytes is used when referring to file size,CD capacity,or video card memory capability,29,Practical Computer Literacy,3rd Edition,What factors affect speed,power and compatibility?,Giga refers to a billion or 1,073,741,824Gigabytes are used to describe RAM,DVD,and hard disk capacityMainframe and supercomputers use tera-(trillion),peta-(quadrillion),and exa-(quintillion),30,Practical Computer Literacy,3rd Edition,31,Practical Computer Literacy,3rd Edition,What factors affect computer speed,power and compatibility?,What factors affect speed,power and compatibility?,32,The three most popular personal computer platforms are PCs,Macs,and LinuxThe PC platform is based on the design of the IBM PCThe Mac platform is based on a proprietary design for the MacintoshThe Linux platform is a standard PC with the Linux operating systemCompatible computers operate in essentially the same way,Practical Computer Literacy,3rd Edition,Whats important about microprocessors?,The most important,and usually the most expensive,component of a computerCircuitry is grouped into important functional areasALU(arithmetic logic unit)performs arithmetic and logical(such as comparing)operationsUses registers to hold data that is being processedControl unit directs microprocessor tasks,33,Practical Computer Literacy,3rd Edition,Whats important about microprocessors?,Microprocessor speed is measured in megahertz(MHz)or gigahertz(GHz)MHz=1 million cycles per secondGHz=1 billion cycles per secondDuring each cycle the microprocessor executes instructionsThe faster the clock speed,the more instructions executed per second,34,Practical Computer Literacy,3rd Edition,Whats important about microprocessors?,Microprocessors are also rated by word sizeMany process a 32-bit word64-bit available,and are faster then 32-bit unitsMicroprocessors manufactured by several companies:IntelAMDMotorolaIBM,35,Practical Computer Literacy,3rd Edition,36,Practical Computer Literacy,3rd Edition,Whats important about microprocessors?,Whats important about computer memory?,RAM(random access memory)is a temporary holding area for data,application program instructions,and the operating systemRAM is the“waiting room”for processorWhen program is started,it is held in RAM until needed and remains there until program is closed,37,Practical Computer Literacy,3rd Edition,Whats important about computer memory?,RAM also holds dataMost RAM is volatile,which means it needs electrical power to hold dataIf power goes out,or computer is turned off,data stored in RAM is instantly and permanently lostIt is important to frequently save work to a permanent storage area,such as hard disk,as you work,38,Practical Computer Literacy,3rd Edition,Whats important about computer memory?,RAM also holds operating system instructions,loaded each time you turn on your computer and held until it is turned offRAM capacity is measured in megabytes or gigabytesTodays computers have between 512 megabytes and 8 gigabytes of RAM,39,Practical Computer Literacy,3rd Edition,40,Practical Computer Literacy,3rd Edition,Whats important about computer memory?,Whats important about computer memory?,Most computers also contain ROM(read only memory)a type of memory that holds the computers startup routineWhereas RAM is temporary and volatile,ROM is permanent and non-volatile,41,Practical Computer Literacy,3rd Edition,Why do computers use multiple storage devices?,Computers feature multiple storage devices,such as:Hard disk drive-the main storage device in most computersProvides lots of storage capacityProvides fast access to filesEconomicalCapacity is measured in gigabytes and speed in milliseconds(ms)or revolutions per minute(RPM),42,Practical Computer Literacy,3rd Edition,43,Practical Computer Literacy,3rd Edition,Why do computers use multiple storage devices?,Why do computers use multiple storage devices?,A CD(compact disk)provides 650-700 MB of storage A DVD(digital video disk or digital versatile disk)is a variation with a capacity of 4.7 GB Can be doubled with dual layer technologyBlu-Ray is storage medium with 25GB capacity for single layerCDs,DVDs,and BDs are:Durable storageUnaffected by magnetic fieldsDust and dirt can be cleaned offBiggest threat are scratches,44,Practical Computer Literacy,3rd Edition,Why do computers use multiple storage devices?,CDs and DVDs come in several varieties:Read only(ROM)permanent data stored during manufacturingRecordable(R)A writable drive can store data but it cant be changed Rewritable(RW)can be changed many times,much like a hard drive but much slower,45,Practical Computer Literacy,3rd Edition,A USB flash drive is a popular removable,portable storage deviceAbout the size of a highlighter penVery durableOpen,edit,delete,and run files just as if they were on hard driveUse solid state storage technologyProvides fast access to data and uses little power,Why do computers use multiple storage devices?,46,Practical Computer Literacy,3rd Edition,Why do computers use multiple storage devices?,In addition to storage devices connected to computer,data can be stored on online storage,47,Practical Computer Literacy,3rd Edition,What kind of protection and maintenance does a computer require?,Large organizations protect equipment from theft with high-tech security systemsProtect personal computer by locking to desk or locking roomWhen traveling by air,carry it in your carry-on bag,48,Practical Computer Literacy,3rd Edition,What kind of protection and maintenance does a computer require?,Make sure computer is balanced safely on desk or resting on floorWhen carrying notebook computer,use padded carrying caseWhen transporting desktop,use original box or protect it with foam padding,49,Practical Computer Literacy,3rd Edition,What kind of protection and maintenance does a computer require?,Environmental factors can do damageExcess heat can damage circuitryHigh humidity can corrode contacts and cablesWater leaks can short out circuitsMagnetic fields can erase dataDust,dirt,and air pollution can cause overheating and clog up mechanical parts,50,Practical Computer Literacy,3rd Edition,What kind of protection and maintenance does a computer require?,Routine cleaning of mouse and keyboard can keep them working smoothlyFollow manufacturers instructions for cleaning to keep printer from jamming and print head from smearingKeep floppy disks and hard disks away from strong magnetic fields,51,Practical Computer Literacy,3rd Edition,What kind of protection and maintenance does a computer require?,Computers are vulnerable to power irregularitiesMake sure power cable is positioned so it cant be accidentally disconnectedWhen going to another country,ensure your equipment conforms to power systemsUse surge strips to protect against power spikes and surgesTo protect against power outages,you can connect to uninterruptible power supply,52,Practical Computer Literacy,3rd Edition,What kind of protection and maintenance does a computer require?,Owners should periodically make backups of data,run a defragmentation utility,and update virus checking softwareConsider following guidelines when troubleshooting:Make sure equipment is plugged inCheck all cables
