PowerPoint Presentation - Operating Systems

Operating Systemsand Windows

What is an Operating System? The most importantprogram that runs on yourcomputer. It manages allother programs on themachine. Every PC has to have one torun other applications orprograms. It’s the first thing“loaded”.

Operating System It performs basic tasks,such as: Recognizing input from thekeyboard or mouse, Sending output to themonitor,

Operating System Keeping track offiles and directorieson the disk, and Controllingperipheral devicessuch as disk drivesand printers.

Is There More Than One Type of OS? Generally, there are four types,based on the type of computerthey control and the sort ofapplications they support.1.Single-user, singletaskThis type manages thecomputer so that one usercan effectively do onething at a time.

Types of Operating Systems2. Multi-user, multi-taskAllows two or more users to runprograms at the same time. Someoperating systems permit hundreds oreven thousands of concurrent users.

Types of Operating Systems3. Real Time Operating SystemsRTOS are used to control machinery,scientific instruments, and industrialsystems.There is typically very little userinterface capability.Resources are managed so that aparticular operation executesprecisely the same every time.

Types of Operating Systems4. Single-user, Multi-taskingThis is the type of operating system mostdesktops and laptops use today.Microsoft’s Windows and Apple’s MacOS areboth examples of operating systems that willlet a single user have several programs inoperation at the same time.

OS’s Manage Applications Operating systems providea software platform on topof which other “application”programs can run. The application programsmust be written to run on aparticular operating system. So, your choice of operatingsystem determines whatapplication software you canrun.

Operating System Functions Besides managinghardware and softwareresources on the system,the OS must manageresources and memory. There are two broadtasks to be accomplished.

OS - Memory Storage and Management1. Each process must haveenough memory in whichto execute, andIt can neither run into thememory space of anotherprocess,Nor be run into by anotherprocess.

OS - Memory Storage and Management1. The different types of memoryin the system must be usedproperly so that each processcan run most effectively.

Cache Memory Cache - A section of acomputer's memorywhich temporarilyretains recentlyaccessed data in orderto speed up repeatedaccess to the same data. It provides rapidaccess without havingto wait for systems toload.

RAM Memory Random accessmemory (RAM) is thebest known form ofcomputer memory. RAM is considered"random access" becauseyou can access any memorycell directly if you know therow and column thatintersect at that cell.

RAM Memory The more RAM your computer has,the faster programs can function.The two main types are calledDRAM and SRAM. SRAM is fasterthan DRAM, but, more expensive.Remember, that if the power is turned off,then all data left in RAM, that has not beensaved to the hard drive, is lost.

Virtual Memory Virtual Memory – a method of usinghard disk space to provide extramemory. It simulates additional RAM. In Windows, theamount of virtualmemory available,equals the amount offree RAM plus theamount of disk spaceallocated to the swapfile.

Virtual Memory – Swap FileA swap file is an area of your hard disk that isset aside for virtual memory. Swap files can beeither temporary or permanent.

Okay – So Now What?

OS - Wake up call When you turn on the power toa PC, the first program that runsis a set of instructions kept inthe computer's read-onlymemory (ROM).

OS - Wake up Call It checks to make sureeverything is functioningproperly. It checks the CPU, memory,and basic input-outputsystems (BIOS) for errors.

OS – Wake up Call Once successful, thesoftware will begin toactivate the computer'sdisk drives. It then finds the first pieceof the operating system:the bootstrap loader.

OS - Booting the PC The bootstrap loader is asmall program that has asingle function: It loads theoperating system intomemory and allows it tobegin operation.

OS - Booting the PC The bootstrap loader sets up thesmall driver programs thatinterface with and control thevarious hardware. It sets up the divisions of memory user information, and applications.

OS - Booting the PC It establishes the datastructures needed tocommunicate withinand between thesubsystems andapplications of thecomputer. Then it turns control ofthe computer over tothe operating system.

Windows DesktopYour Desktop maylook like this

Windows Desktop Or like this.

How Do I Tell The OS What I Want To Do? You must continue to givethe operating systemcommands that are acceptedand executed. The first command waspushing the “ON” button whichstarted the “boot” process.

Enter Commands Commands can beentered several ways: Through a keyboard. Pointing or clicking onan object with a mouse.(Graphical User Interface or GUI) Sending a commandfrom another program.

Windows and Mac are GUI’s Microsoft Windows and Apple Macintoshoperating systems are “graphical userinterfaces” or GUI’s.GUI is defined as: A picture used in place ofa word or words to issue commands.

GUI – Standards GUI interfaces have standards thatare usually the same or similar in allsystems and applications. Standards apply to: Pointers and pointing devices Icons, desktops, windows and menus

Windows - GUI Pointers GUI uses pictures, symbols, or icons ratherthan words to represent some object orfunction. For example: A pointer or mouse pointer is asmall arrow or other symbol thatmoves on the screen as you movea mouse. An I-Beam pointer is used by manydesktop publishing systems and wordprocessors to mark blocks of text andmove the insertion point.

GUI – Cursors / Pointers The term“cursor” typicallyis used to showwhere your typingwill appear.Otherwise, theterm “pointer” isthe better choice.

Windows - GUI Icons Icon - A small picture that represents acommand, object, file, or window. Point and click with a mouse to execute acommand or convert the icon into a window. Icons are moveable around the displayscreen, just like moving things around onyour desk.

Object Icons & Shortcut Icons One type oficon is anobject icon.It allowsyou to openapplicationsanddocumentson your PC. You can createand use ashortcut icon toopen anyapplicationquickly. Youdon’t have touse the StartMenu to accessa program ordocument.

Windows - GUI Windows & Desktop You can divide the screen intodifferent areas. In each window, you can run adifferent program or display adifferent file. You can move windows around thedisplay screen, and change theirshape and size at will.

Windows - GUI Menus Menu - is an on-screen listof options for using aprogram. It can also be alist of categories with manyother menu options underit. Menus can "pop up" or"pull down."

GUI – Share Data Because the formats are well-defined,different programs that run under a commonGUI can share data. This makes it possible,for example, to copy a graph created by aspreadsheet program into a documentcreated by a word processor.

Parts of the Desktop

Windows - Taskbar Taskbar – shows you the windowsor programs that are currently openon the desktop. You can switchbetween windows by clicking on theapplicable button.

Windows – System Tray System Tray – shows you runningprograms that were startedautomatically by the operatingsystem, like anti-virus programs, theclock and volume controls. Theseprograms are running in thebackground.

Windows - Quick Launch Toolbar Quick Launch Toolbar – containsone-click buttons, or shortcuts,which open programs. You cancustomize this toolbar however youlike.

Start Button The start button allows you to easilyaccess your computer programs orconfigure Windows. By default thestart button is located at the bottomleft side of the screen.

Parts of a Window

Title Bar At the top edge of the window, insideits border, is the title bar which extendsacross the width of the window. Itcontains the title of the application ordocument. A small icon in the far left corner ofthe title bar represents the object beingviewed in the window.

Minimize, Maximize and Resize Windows The title bar contains three littlebuttons in the upper right-corner of thewindow and are used to manage thewindow size or close it altogether.

Minimize - Maximize The first button is the minimizebutton and it will hide the window.The window can be opened againby clicking its button on thetaskbar. The second button is maximize,which makes the window takeup all the screen space. Clickingagain turns the window back tothe size it was. The double-boximage is known as the restorebutton.

Close Window The last button willclose a window. If it isthe last window of acertain type ofprogram, it will exit orquit that program.

Move a Window You can move a window to anylocation on the desktop by “clickingand dragging” the title bar with yourmouse. This is also referred to as“drag and drop”. You can alsodrag and dropicons to movethe location offiles or shortcuts.

Menu Bar Menu bar - The horizontal bar near thetop of a window that displays thenames of menus from which you canaccess features and perform tasks forthe current application.

Types of Menu Items Arrow: another menuwill cascade from it. Three dots: a dialogbox will open,containing choicesfor you to make.

Types of Menu Items Checkmark:clicking this itemwill toggle thefeature on or off. If a keyboardshortcut is shown inthe menu, you canuse those keys torun the commandwithout having toopen the menu.

Scroll Bar Scroll bar - the narrowrectangular bar at the farright of windows. Clicking on the up or downarrow enables you to moveup and down through adocument. A movable squareindicates your location inthe document.

Windows Frame & Resizing You can also resize awindow by a click anddrag move.Put the mouse cursor on theedge of a window (that is notmaximized) and when thepointer changes to a doublearrow, click and drag for thenew size. Some windowshave a handle on them forresizing.

Status Bar Status bar – is located at thebottom of a window and containsinformation about formattingoptions, errors, prompts,messages, or the status of anapplication.

Dialog Boxes1. List box2. Spin control box3. Slide4. Drop-down list5. Radio button6. Checkbox7. Text box

Windows – Start Menu Start Menu – gives you access to allprograms and functions on your PC,including “help” files and “search”capabilities.

Windows HELP AccessWindowsHELP throughthe Startmenu.Windows 95 HELP menu

Windows HELPWindows 98 HELP menu

Windows HELP Windows XP HELP menu

Windows System Programs Windows has a number of internalprograms as part of the operating systemthat help keep you organized and yourPC healthy. Here are a few:

Windows - My ComputerAlsthe o kEx Wi nowplo nd n arer ows s My Computer – inside this icon you can find everyfolder and file that your PC has access to.

Windows – Recycle Bin Recycle Bin – Deleted files and folders go herefirst, where they wait to be permanently deletedby you, or by rules that you set up. This is atemporary storage area on your hard drive.

Windows – My Docs My Documents – a place to storethe documents and files youcreate. Clicking on this opens anexplorer window displaying thedetail. It’s wise to keep the files youcreate separate from the programfiles, so when you backup yourdata, it’s all located in onelocation. You can then backupjust this area of your storage.

My Documents – Explorer Window

Windows – Network Neighborhood Network Neighborhood –serves as a window into thenetwork resources you haveon your PC. If you are connected to anetwork you will see allthe other PC’s linked toyour network and you canshare files, printers orother hardware.

Network Neighborhood

Logoff If your have multiple users on a PCwith separate “profiles” or userlogons, use the logoff process toclose out of your profile or toswitch users.