Kĩ thuật lập trình - Software

1Software3.1 System Software: The Power behind the Power3.2 The Operating System: What It Does3.3 Other System Software: Device Drivers & Utilities3.4 Common Features of the User Interface3.5 Common Operating Systems3.6 Application Software3.7 Word Processing3.8 Spreadsheets3.9 Database Software3.10 Specialty SoftwareChapter3McGraw-Hill/Irwin© 2007 The McGraw-Hill Companies, Inc. All rights reserved. System Software: The Power behind the PowerApplication SoftwareSoftware developed to solve a particular problem for usersEither performs useful work on a specific task Or provides entertainmentWe interact mainly with this softwareSystem SoftwareEnables application software to interact with the computerHelps the computer to manage its own internal and external resources3 System Software: The Power behind the PowerSystem Software has 3 basic componentsOperating System (OS)The principal component of system softwareLow-level, master system of programs to manage basic computer operationsSome hardware requires specific Operating Systems Macintosh computers run Macintosh OS PCs run Microsoft Windows, Linux, or BSD UnixIBM Mainframes run MVS or VMCray supercomputers run COS or UNICOSDevice DriversHelp the computer control peripheral devicesUtility ProgramsUsed to support, enhance, or expand existing programs in the computer4 The Operating System: What It DoesBootingThe process of loading an OS into the computer’s main memoryThe steps are:Turn the computer onDiagnostic routines test main memory, CPU, and other hardwareBasic Input/Output System (BIOS) programs are copied to main memoryBIOS contains instructions for operating the hardwareThe computer needs those instructions to operate the hardware and find a copy of the OSBoot program obtains the OS and loads it into computer’s main memory5 The Operating System: What It DoesCentral Processing Unit (CPU) ManagementKernel is the supervising software that manages CPUKernel must remain in memory while the computer runsIf another program uses the kernel’s memory when the kernel needs it, the computer will crashMemory ManagementOS keeps track of memory locations to prevent programs and data from overlapping each otherSwaps portions of programs and data into the same memory but at different timesKeeps track of virtual memoryQueues, Buffers, Spooling6 The Operating System: What It DoesCentral Processing Unit (CPU) Management (continued)Queues, Buffers, SpoolingQueue: First-in, First-out (FIFO) sequence of data or programs that waits in line for its turn to be processedBuffer: The place where the data or programs sit while they are waitingTo Spool: The act of placing a print job into a bufferNeeded because the CPU is faster than printersThe CPU can work on other tasks while the print jobs wait7 The Operating System: What It DoesFile ManagementA file is either aData File: a named collection of dataProgram File: a program that exists in a computer’s secondary storageThe File System arranges files in a hierarchical mannerTop level is Directories (aka Folders)Subdirectories come below FoldersFind files using their pathnameC:/MyDocuments/Termpaper/section1.doc8 The Operating System: What It DoesTask ManagementRequired for computers that accommodate multiple usersRequired for computers that allow multiple simultaneous applications Methods of processing two or more programsMultitaskingBy one user on one processorMultiprogrammingBy multiple users concurrently on one processorTime-sharingBy multiple users in round-robin fashion on one processorMultiprocessingBy one or more users simultaneously on two or more processors9 The Operating System: What It DoesSecurity ManagementOperating Systems permit users to control access to their computersUsers gain access using an ID and passwordYou set the password the first time you boot up a new computerSystem Administrators can set up new accounts and assign new passwords10 Other System Software: Device Drivers & UtilitiesDevice DriversSpecialized software programs that allow input and output devices to communicate with the rest of the OSWhen you get a brand-new printer or monitor, you may also need to install the device driver for itDevice drivers come with new hardware, or download from the manufacturer’s website, or sites like www.driverguide.com or www.windrivers.com UtilitiesService programs that perform tasks related to the control and allocation of computer resourcesSome come with the OS, others can be bought separately likeNorton SystemWorks, McAfee Utilities11 Other System Software: Device Drivers & UtilitiesPractical Utility programs perform the following tasksVirus protectionData compressionFile defragmentationDisk scanner & disk cleanupBackupData recoveryDiscussion Question: How many of you have lost important files such as a term paper? Didn’t you wish you had made a backup copy? ALL data media are subject to possible failure and data loss!12Common Features of the User InterfaceUser InterfaceThe user-controllable display screen you use to interact with the computerKeyboard and MouseUser input devices that you use to interact with the display screenBoth devices have special-purpose keysKeyboard Special-purpose keys: Esc, Ctrl, Alt, Del, Ins, Home, End, PgUp, PgDn, Num LockMouse special-purpose keys: left-click, right-click, and (on some mice) scroll wheel or center click13Common Features of the User InterfaceKeyboardFunction Keys – let you quickly perform specific tasksEscape Key – lets you quit a taskCtrl and Alt – use combination with another key to bypass using the mouse – Ctrl + S will save a document, Alt + Tab will let you switch between running applications14Common Features of the User InterfaceKeyboard continuedApplication key – quickly displays the shortcut menu for any item on your screenStatus lights – indicate if your Num Lock or Caps Lock keys are on Numeric Keypad – allows you to type in numbers when the Num Lock light is on15Common Features of the User InterfaceMouseHandy tool for dragging and dropping text, graphicsUseful for navigating menus on unfamiliar applications16Common Features of the User InterfaceGraphical User Interface (GUI)Allows you to use a mouse or keystrokes to select icons and commands from menusReplaces command-driven interfaces used in earlier programsThree main features are: desktop, icons, and menusDesktop: The system’s main interface screenIcon: Small pictorial figure that represents a program, data file, or procedure Rollover: A small text box that explains the icon when you roll your mouse over itMenus: A list of built-in commands and/or options from which to choose 17Common Features of the User InterfaceTo start an application, pick one of 3 methods:Click on the Start button on the lower left corner of the Windows desktopClick on the My Computer icon on the desktop, find the application executable on your hard disk, and click itClick on the My Documents icon on the desktop, find the document you want to open, and click it. It should automatically open the application that created it, if you have that application installed18Common Features of the User InterfaceMost Operating Systems have the following:Title Bar: runs across the top of the display windowMenu Bar: shows the names of the pull-down menus availableToolbar: Displays menus and icons representing the most-frequently used commandsTaskbar: The bar across the bottom of the Windows screen that contains the Start buttonA window: A rectangular frame on the computer screen through which you can view a file of data or an application 19Common Operating SystemsPlatformThe particular processor model and operating system on which a computer system is basedOperating Systems are platform-specificPC (Wintel) platformsDell, Compaq, Hewlett-Packard, IBM PCsOriginally ran Disk Operating System (DOS)Currently run Linux, Unix, WindowsApple (Macintosh) platformsRun Mac OS (System 9 was proprietary, OS X is Unix-based)20Common Operating SystemsMac OSThe OS that runs on Apple Macintosh computersPioneered the easy-to-use GUIProprietary OSSystem 9 is OS from 1999, but still popularMac OS X is based on BSD Unix kernelTiger is 2005 release of Mac OS X; features includeSpotlight – a desktop search engine for locating files on local hard diskDashboard – for creating desktop “widgets”Automator – automatically helps users to script repetitive tasks21Common Operating SystemsUnix, Solaris, BSDDeveloped at AT&T Bell Laboratories in 1969 as minicomputer operating systemIs a multitasking operating system with multiple users that has built-in networking capability and a version for every platformUnix interfaceGUI – An optional shell program that starts after the kernelCommand interface – starts when kernel loads22Common Operating SystemsLinuxA flavor (version) of UnixA free, nonproprietary version of UNIXMay legally be downloaded and used for freeMay legally be modified for free, as long as modifications aren’t copyrightedIn 2000, adopted by China as national standard OSLinux vendors produce Linux DistributionsSoftware is distributed for freeSupport services are sold for a profitMany PCs are set up to dual-boot Linux and Windows23Common Operating SystemsOperating Systems for HandheldsPalm OSDominant handheld OSProprietary OS requires proprietary softwareWindows CEHas familiar Windows look and feelCan be directly programmed using Visual Basic 2005Symbian OSSymbian is world’s largest producer of smartphone softwareSoftware is open-source24Application SoftwareThere are 5 ways to legally obtain softwareCommercial SoftwareCopyrighted – license must be purchasedPublic-domain softwareNot copyrighted – legal to copySharewareCopyrighted – download for free, then pay if you use itFreewareCopyrighted – but available for free. Pay on honor systemRentalwareCopyrighted – lease for a fee25Application SoftwareSoftware License TypesSite licensesAllow software to be used on all computers at a specific locationConcurrent-user licenseAllows a specified number of copies to be used at one timeMay require additional license-monitoring softwareMultiple-user licenseSpecifies the number of people who may use the softwareSingle-use licenseLimits the software to one user at a time26Application SoftwareOther software categoriesPirated softwareSoftware obtained illegally in violation of copyrightSoftware & Industry Information Association Anti-Piracy division prosecutes violators of software copyright laws Don’t pirate software!!!AbandonwareSoftware that is no longer being sold or supported by its publisherSubject to copyright for 95 years from date of publication27Application SoftwareImporting filesGetting data from another source and converting it into a format for the application you are usingAllows you to edit files from other applicationsExporting filesTransforming data into a format that can be used by a different application, then transmitting itCommon export files end in the .rtf extension28Word ProcessingSoftware that uses computers to create, edit, format, print, and store text.Microsoft Word licensed for Windows and Mac OSLotus Smart Suite licensed for WindowsSun Microsystems Star Office licensed for Windows- Linux- and Solaris-based systems (was free)Corel Word-Perfect licensed for Windows29Word ProcessingTools for creating documentsCursor is on screen to show you where to enter textScrolling means moving quickly forward, up, down, or sideways through document test displayWord wrap automatically continues text to next line when you reach the right marginOutline view puts tags on headings within a document to organize itInserting is the act of adding text to documentsDeleting is the act of removing text from documents30Word Processing31Word ProcessingFind & ReplaceFind lets you go straight to any text in your documentReplace lets you go to the text and automatically replace it with something elseCut, Copy, & PasteSelect the text you want to moveCopy to clipboard, then paste in new locationOr drag the text to the new locationSpelling CheckerTests for incorrectly spelled wordsOften shows them with a squiggly line underneathYou may choose to use the “Autocorrect” feature32Word ProcessingGrammar CheckerHighlights poor grammar, wordiness, sentence fragments, and awkward phrasesPuts different-color squiggly line under suspect phrasesThesaurusCan be called up on-screenOffers suggestions for alternative words with the same meaningDiscussion Question: How doze a spell-checker Handel different spellings for the same word? Should ewe trust the spell-checker for everything?33Word ProcessingFormatting Documents using Templates & WizardsA template is a preformatted document that provides basic tools for shaping a final documentYou can customize a template with your company’s name, address, etc, then save it and use it again and againUse them when you have to repeatedly create the same basic documentA wizard is an interactive computer utility program that leads the user through a task asking questions and using the user’s answers to customize a solutionLetter wizards create customized lettersMemo wizards help you to create memoranda34Word ProcessingFormattingFontThe typeface, size, and color of your lettersAlso lets you specify underlined, italic, or boldSpacing & ColumnsChoose how far apart the lines will be (single- or double-spaced)Choose single-column or multi-columned text for your documentMargins & JustificationIndicate width of left, right, top, and bottom marginsJustify text left, right, or center35Word ProcessingHeaders, footers, page numbersA header is text printed at the very top of the pageA footer is text (like page number) at the page bottomOther FormattingYou can specify a border around a document or around a paragraph – it can really highlight a pointYou can also use shading, tables, and footnotesDefault SettingsThese are the settings automatically used by the program unless you change them36Word ProcessingSaving a documentStore a document as an electronic fileFile  Save or click Floppy icon or Ctrl + SSave often, and save in two placesPrint Print individual pages, the whole document, or several copiesFile  Print or click printer icon or Ctrl + PTrack ChangesSave as Web Document37SpreadsheetsElectronic spreadsheets were created in 1978 by Daniel Bricklin at Harvard Business School and Daniel Fylstra at M.I.T. and HBS as a study toolSpreadsheets are organized into columns and rowsCells are where a row and a column meetCell address is the position of the cellRange is a group of adjacent cellsValues are numbers or dates entered into a cellCell pointers or cursors are where the data is to be entered38Spreadsheets39SpreadsheetsFormulas, Functions, Recalculation, What-IfFormulas are instructions for calculationsThey define mathematically how one cell relates to another cellExample: =SUM(A5:A15) sums the values of the cells A5, A6, A7, and so forth up through cell A15Functions are built-in formulas, such as SUM()Recalculation is the process of recomputing valuesWhat-If analysis allows users to see what happens to totals when one or more numbers change in cellsThis is the powerful feature of spreadsheets over manual calculations40SpreadsheetsCharting and Analytical GraphicsSpreadsheets allow you to automatically create graphsWhen the cells change, the graphs change tooCharts are a type of graph that includeBar chartsColumn chartsLine graphsPie chartsScatter charts41Database SoftwareA database is a structured collection of interrelated files in a computer system with built-in data input and retrieval methods.In databasesData redundancy is minimizedData is integrated and stored in a structured fashionData in databases has more integrity than does data stored in separate filesData is organized into tables, records, and fieldsData may include text, numbers, and graphics42Database Software43Database SoftwareDatabase features includeLinking records using a keyTables that contain the same field are linked together by fields, so the key can be updated just onceKey fields can also be used to sort data Querying and displaying recordsOffer a quick way to locate records quicklySaving, Formatting, Printing, Copying, TransmittingDatabase software allows you to create custom input forms, custom reports, copy search results and paste them into Word, print out addresses to mailing labels, or attach to email44Specialty SoftwarePresentation GraphicsDesktop PublishingFinancial SoftwareDrawing and Painting SoftwareProject Management SoftwareVideo-audio Editing SoftwareAnimation SoftwareWeb Page Design Software45Specialty SoftwarePresentation Graphics SoftwareUse graphics, animation, sound, data, or information to make visual presentationsFor example, this presentationContains Design and content templatesSlide sortersOutline viewSlide viewNotes Page View46Specialty Software47Specialty SoftwareFinancial SoftwareRanges from personal-finance managers to entry-level accounting programs to business financial-management packagesCommon featuresTrack income and expensesAllow checkbook managementDo financial reportingOffer tax categories to assist with tax recordkeepingMay also offer financial-planning and portfolio-management features48Specialty SoftwareDesktop PublishingInvolves mixing text and graphics to produce high-quality output for commercial printingUses a mouse, scanner, printer, and DTP softwareHas the following featuresMix of text with graphicsOffers varied type and layout stylesAllows import of files from other programsDrawing programsGraphics software used to design and illustrate objects and products49Specialty SoftwarePainting programsGraphics programs that allow users to simulate painting on-screenProduce bit-mapped or raster imagesAlso called image-editing softwareGraphics file formats.bmp (bit-map).gif (Graphic Interchange Format) – copyrighted format used in web pages.jpeg (Joint Photographic Experts Group)- high-resolution.tiff (Tagged Image File Formats) – PC and Macs for high-resolution images to print.png (Portable Network Graphics) – public domain alternative to gif50Specialty SoftwareVideo editing softwareAllows import to and editing of video footage on PCVideo editing examples include Adobe Premiere, Sony Pictures Digital Vegas, Apple Final Cut Express, Pinnacle Studio DV, and Ulead VideoStudioAudio editing software Allows import to and editing of sound files on PCSound editing examples include Windows Sound Recorder, Sony Pictures Digital Sound Forge, Audacity (freeware), Felt Tip Software’s Sound Studio (shareware), GoldWave, and WavePad.51Specialty SoftwareAnimation SoftwareSimulates movement by rapidly displaying a series of still pictures, or framesGIF is the first format to catch on52Specialty SoftwareMultimedia Authoring SoftwareCombines text, graphics, video, animation, and sound in an integrated way to create stand-alone multimedia applicationsRequires fast computer, lots of memory, and good, fast graphics cardMacromedia Director and Macromedia Authorware are popular examplesWeb Page Design SoftwareUsed to create web pages with sophisticated multimedia featuresNot required to create simple web pages53Specialty SoftwareProject Management SoftwareA program used to plan and schedule the people, costs, and resources required to complete a project on timeShows project broken down into steps and tasksEach task has a beginning and end dateTasks can be scheduled concurrently or consecutivelyComputer-Aided Design (CAD)Programs intended for design of products, structures, civil engineering drawings, and mapsProvide precise dimensioning and positioning of design elementsExamples include AutoCAD, ProEngineer, CorelCAD, CATIATo see an example, go to for CATIA54