计算机应用基础(双语)课件PPTCha.pptx

Chapter 1 Computer Hardware Whats inside? In this chapter, you will: Gain an overview of computer equipment and terminology Learn how computers are classified Learn how personal computers fit into the gamut of machines from PDAs to supercomputers Review basic components of a typical personal computer system Look inside the system unit Explore advantages and disadvantages of several computer storage devices Learn some basics about maintaining your computer and troubleshooting problems 2Practical Computer Literacy, 3rd Edition What is a computer? A device that: Accepts input Processes data Stores data Produces output 3Practical Computer Literacy, 3rd Edition What is a computer? Computer input is whatever is typed, submitted, or transmitted to a computer system Data refers to symbols that represent facts, objects, and ideas Processing is manipulation of data Most takes place in central processing unit (CPU), a computers “brain” Computer programs are instructions that tell computers how to process 4Practical Computer Literacy, 3rd Edition What is a computer? An operating system is software that helps a computer operate efficiently and keep track of data Application software helps users “apply” computers to specific tasks Memory is temporary storage Storage is permanent Computer output is results produced by computer 5Practical Computer Literacy, 3rd Edition What is a computer? 6Practical Computer Literacy, 3rd Edition How are computers classified? Computers are divided into five categories: Handheld computers Personal computers Servers Mainframe computers Supercomputers 7Practical Computer Literacy, 3rd Edition How are computers classified? Handheld computer (PDA) features include: Small keyboard or touch-sensitive screen Designed to fit in your pocket Runs on batteries Used while holding it 8Practical Computer Literacy, 3rd Edition How are computers classified? A personal computer is designed to meet the computing needs of an individual Desktop computers fit on desks and run on power from wall outlets A Notebook computer (laptop) incorporates screen, keyboard, storage, and processing 9Practical 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 users A supercomputer is one of the fastest computers in the world and can tackle complex tasks How are computers classified? 11Practical Computer Literacy, 3rd Edition Can computers connect to each other? A PDA can connect to desktop with a cable or wireless link Personal computers can connect to each other or larger computers via wired or wireless computer networks A computer network can be as few as two or as many as thousands of computers The Internet is the worlds largest network, connecting millions of computers 12Practical Computer Literacy, 3rd Edition Can computers connect to each other? Computers can be connected using a centralized model or a distributed model A Centralized computing system depends on a centrally-located computer for processing and storage A distributed computer network spreads the processing and storage tasks among many computers 13Practical 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 registration Commercial applications include inventory, payroll, and point-of-sale Hospital and healthcare organizations applications include patient records, integrated diagnostic tools, patient billing, and health insurance claims processing In education, applications include course registration, student records, budgeting, and payroll 15Practical Computer Literacy, 3rd Edition What are the components of a personal computer system? Included in a typical personal computer system are: System unit Display device Keyboard Mouse/Trackpad Storage devices Memory card slots USB ports Sound card and speakers Webcam Network circuitry Printer 16Practical Computer Literacy, 3rd Edition What are the components of a personal computer system? 17Practical 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 circuit An integrated circuit is a super-thin slice of semi- conducting material packed with microscopic circuit elements A microprocessor is an integrated circuit designed to process instructions. 18Practical Computer Literacy, 3rd Edition Whats inside the system unit? 19Practical Computer Literacy, 3rd Edition How do computer circuits manipulate data? Most computers are electronic, digital devices Digital devices work with discrete data, such as digits 1 and 0, or like a light switch on or off Analog devices work with continuous data, like a dimmer switch with continuous range 20Practical Computer Literacy, 3rd Edition How do computer circuits manipulate data? Most computers use simplest technology of two possible states, like on-off switch Usually we indicate “on” state as 1 and “off” state as 0 These 1s and 0s are referred to as binary digits or shortened to bits Computers use sequences of bits to digitally represent numbers, letters, punctuation marks, music, pictures, and videos 21Practical 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 character Extended ASCII requires eight bits for each character EBCDIC is eight-bit technology used on older, IBM mainframe computers Unicode uses sixteen bits and provides code for 65,000 characters 22Practical Computer Literacy, 3rd Edition 23Practical Computer Literacy, 3rd Edition How do computer circuits manipulate data? What factors affect computer speed, power and compatibility? Computers have three major components: Processor Memory Storage When a program is started, it is moved from storage to memory The processor fetches program instructions from memory, then begins to execute 24Practical Computer Literacy, 3rd Edition If instructions require data, the processor fetches it from storage, loads it into memory, then transfers it to the microprocessor The results are sent back to memory The results can be stored or sent to output printer or screen 25Practical 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 speed Memory capacity Hard disk drive speed and organization Display capability and video memory Network and modem connection speed 26Practical 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) 27Practical Computer Literacy, 3rd Edition What factors affect speed, power and compatibility? In world of computers kilo means 1024, not 1000 Kilobit is 1024 bits and kilobyte is 1024 bytes Kilobytes is often used when referring to size of small computer files 28Practical Computer Literacy, 3rd Edition What factors affect speed, power and compatibility? Prefix “mega” means a million, or in context of bits and bytes, 1,048,576 Megabits is used when referring to speed of data transmission Megabytes is used when referring to file size, CD capacity, or video card memory capability 29Practical Computer Literacy, 3rd Edition What factors affect speed, power and compatibility? Giga refers to a billion or 1,073,741,824 Gigabytes are used to describe RAM, DVD, and hard disk capacity Mainframe and supercomputers use tera- (trillion), peta- (quadrillion), and exa- (quintillion) 30Practical Computer Literacy, 3rd Edition 31Practical 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 Linux The PC platform is based on the design of the IBM PC The Mac platform is based on a proprietary design for the Macintosh The Linux platform is a standard PC with the Linux operating system Compatible 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 computer Circuitry is grouped into important functional areas ALU (arithmetic logic unit) performs arithmetic and logical (such as comparing) operations Uses registers to hold data that is being processed Control unit directs microprocessor tasks 33Practical Computer Literacy, 3rd Edition Whats important about microprocessors? Microprocessor speed is measured in megahertz (MHz) or gigahertz (GHz) MHz = 1 million cycles per second GHz = 1 billion cycles per second During each cycle the microprocessor executes instructions The faster the clock speed, the more instructions executed per second 34Practical Computer Literacy, 3rd Edition Whats important about microprocessors? Microprocessors are also rated by word size Many process a 32-bit word 64-bit available, and are faster then 32-bit units Microprocessors manufactured by several companies: Intel AMD Motorola IBM 35Practical Computer Literacy, 3rd Edition 36Practical 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 system RAM is the “waiting room” for processor When program is started, it is held in RAM until needed and remains there until program is closed 37Practical Computer Literacy, 3rd Edition Whats important about computer memory? RAM also holds data Most RAM is volatile, which means it needs electrical power to hold data If power goes out, or computer is turned off, data stored in RAM is instantly and permanently lost It is important to frequently save work to a permanent storage area, such as hard disk, as you work 38Practical 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 off RAM capacity is measured in megabytes or gigabytes Todays computers have between 512 megabytes and 8 gigabytes of RAM 39Practical Computer Literacy, 3rd Edition 40Practical 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 routine Whereas RAM is temporary and volatile, ROM is permanent and non-volatile 41Practical 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 computers Provides lots of storage capacity Provides fast access to files Economical Capacity is measured in gigabytes and speed in milliseconds (ms) or revolutions per minute (RPM) 42Practical Computer Literacy, 3rd Edition 43Practical 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 technology Blu-Ray is storage medium with 25GB capacity for single layer CDs, DVDs, and BDs are: Durable storage Unaffected by magnetic fields Dust and dirt can be cleaned off Biggest threat are scratches 44Practical 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 manufacturing Recordable (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 45Practical Computer Literacy, 3rd Edition A USB flash drive is a popular removable, portable storage device About the size of a highlighter pen Very durable Open, edit, delete, and run files just as if they were on hard drive Use solid state storage technology Provides fast access to data and uses little power Why do computers use multiple storage devices? 46Practical 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 47Practical Computer Literacy, 3rd Edition What kind of protection and maintenance does a computer require? Large organizations protect equipment from theft with high-tech security systems Protect personal computer by locking to desk or locking room When traveling by air, carry it in your carry-on bag 48Practical 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 floor When carrying notebook computer, use padded carrying case When transporting desktop, use original box or protect it with foam padding 49Practical Computer Literacy, 3rd Edition What kind of protection and maintenance does a computer require? Environmental factors can do damage Excess heat can damage circuitry High humidity can corrode contacts and cables Water leaks can short out circuits Magnetic fields can erase data Dust, dirt, and air pollution can cause overheating and clog up mechanical parts 50Practical Computer Literacy, 3rd Edition What kind of protection and maintenance does a computer require? Routine cleaning of mouse and keyboard can keep them working smoothly Follow manufacturers instructions for cleaning to keep printer from jamming and print head from smearing Keep floppy disks and hard disks away from