Using the Input Devices - Lecture 3

Lecture 3Using the Input DevicesSummary of Previous LectureParts of Computer SystemsComputer HardwareProcessor, MemorySoftware systemApplication software, system software, utility programsDataUserInformation Processing cycleToday’s ObjectivesIdentify the five key groups on a standard computer keyboard.Describe the purpose of a mouse and the role it plays in computing.Identify the five essential techniques for using a mouse.Identify three common variants of the mouse.How to reduce stress injuries from computer useThe KeyboardThe KeyboardA computer keyboard is a hardware device that functions in accordance to the instructions made by the user. It comprises circuits, switches and processors that help in transferring keystroke messages to the computer. Keyboard skill is call Keyboarding.Keyboard connectorKeyboards are generally plugged into the rear of the CPU, on the motherboard, using a purple PS/2 connector, or on USB port. What is Keyboarding?The ability to enter text by using the correct fingers without looking at the keys (also known as touch typing).Having adequate keyboarding skills to enable you to use the computer more effectively and be more productive.The KeyboardIn today's technology driven world, everyone is aware about computing and the usage of computer keyboard. We all know that keyboard is an input device that functions in accordance to the instructions of the user. Computer keyboards are used for performing various tasks such as typing on a word processor or text editor, accessing menus and playing games. Though pressing a key corresponds to typing a letter, sign or symbol, it may also represent computer commands. For example, pressing the F5 key is a command for refreshing. A standard computer keyboard has about 80-110 keys.Most keyboards use the QWERTY layout, named for the first six keys in the top row of letters. The Keyboard - Standard Keyboard Layout 5. Cursor-movement keys4. Modifier keys3. Function keys2. Numeric keypad1. Alphanumeric keysMost keyboards have keys arranged in five groups:The Keyboard - Standard Keyboard Layout Parts of KeyboardAlternate KeyAlso called ALT keyExecutes commands with other key(s)Tab KeyMoves the cursor/insertion point to a preset position. Used to indent paragraphs or to type columns. TabArrow KeysMove the cursor/insertion point in the direction indicated by the arrow on each keyBackspace KeyRemoves (erases) the character to the left of the insertion point. Use the right little finger to operate the key.BackspaceCaps Lock KeyUsed for keying a string of (three or more) all capital letters. Capitalizes all letters when used. If caps lock mode is in use and a letter is keyed while holding down a shift key, a lowercase letter will be keyed. Function KeysSpecial keys located at the top of the keyboard (F1, F2, F3, F4, etc.) that are used alone or with the CTRL, ALT, and Shift keys to execute software commandsControl KeyAlso called CTRLExecutes commands with other key (s)Delete KeyRemoves (erases) the character to the right of the cursor/insertion pointInsertHomePageUpDeleteEndPage DownDelete vs. Backspace“Hello, my name is Mr. Iqbal.” (The cursor should be on the right side of what I want to remove using Backspace, but the cursor should be on the left side of what I want to remove using Delete.)History Of The KeyboardSholes and Glidden tried to make the typewrite fast.However, one problem with the typewriters keys (hammer bars used to strike the paper) jammed when the operator typed at any real speed, Later, Christopher Latham Sholes invented what was to become known as the Sholes keyboard: (around 1874) for computing devices. Christopher was known for helping with the typewriters and the QWERTY keyboard.Sholes KeyboardHistory Of The KeyboardThe first keyboard was named the “QWERTY” keyboard, this name came from the top letters in a keyboard.The reason they continued qwerty on the keyboard is because people liked the arrangement on the typewriter and they wanted it to continue the way it was.With that information Christopher made the QWERTY.The Dvorak Keyboard 1936Dvorak turned his attention to the typewriter. He spent time to analyze the usage model of the QWERTY keyboard.The results of his investigation were that, although the majority of users were right-handed, the existing layout forced the weaker left hand to perform most of the work. Dvorak took the opposite tack to Sholes, and attempted to find the optimal placement for the keys based on letter frequency and human anatomy. i.e.; he tried to ensure that letters which are commonly typed together would be physically close to each other.The Dvorak Keyboard 1936The (usually) stronger right hand would perform the bulk of the work, while the left hand would have control of the vowels and the lesser-used characters History Of The KeyboardThe reason why Sholes was a success was because his most used letters were spread all over the place, making it easier to type. His was the one we use today and he made his like its made because then the letters that go together are split up and it is good for faster, more efficient typing.Functioning of a Computer KeyboardThe keys may vary depending upon the brand and the type of operating system. Nevertheless, the shape, size and spacing of keys are almost same for all keyboards. The working of a computer keyboard can be compared to a miniature computer. Inside the keyboard, there are metallic plate, circuit board (key matrix) and processor, which are responsible for transferring information from the keyboard to the computer. Depending upon the working principle, there are two main types of keys, namely, capacitive and hard-contact. Let's discuss in brief about the functioning of capacitive and hard contact key.The Keyboard - How a Keyboard Works The keyboard controller detects the keystroke.The controller places a scan code in the keyboard buffer, indicating which key was pressed.The keyboard sends the computer an interrupt request, telling the CPU to accept the keystroke.Operating system responds Controller repeats the letter if heldWhen you press a key: The Keyboard - How a Keyboard Works Inside KeyboardMicrosoft Windows-compatible keyboardsMicrosoft has defined three new keys, which are used for shortcuts to certain Windows features. These three new keys are, from left to right: The left Windows keyThe right Windows keyThe Application key3A-30A Microsoft Keyboard3A-31Different types of a keyboard todayWirelessCordedLaptopGaming (Xbox,Ps3, Etc)Thumb-Size (Phones, PDA’s, Etc.)NumericVirtualTouch screensThe MouseWhat Is a Mouse?The mouse is a pointing device. You use it to move a graphical pointer on the screen.The mouse can be used to issue commands, draw, and perform other types of input tasks. 3A-34History Of a MOUSEThe mouse didn’t always look the way it does. When the creator of a mouse, Douglas Engelbart, first made the mouse in 1964 (first prototype), it was a piece of wood with metal wheels inside of it.The first known publication of the term mouse as a pointing device is in Bill English's 1965 publication "Computer-Aided Display Control“.History Of Mice Six years after Engelbart made the mouse they gave it the name of “Mouse” because it had the tail that came out of it to connect to the computer.History Of MOUSEIn 1968 Engelbart held a presentation to show he had made the mouse, what it was used for, and why people should use this.Because of this presentation he won an award for a great technology achievement, and he won $500,000.Later he was put into the hall of fame for inventors.                                                                         History Of MOUSEAfter Bill’s mouse the next kind of mouse that came out was a mouse that moves from the laser moving to certain new spots, sound familiar?After Bills Prototype mouse it then went to our kinds!The Mouse - Mouse Techniques Pointing; Move the mouse to move the on-screen pointer.Clicking; Press and release the left mouse button once.Double-clicking; Press and release the left mouse button twice.Dragging; Hold down the left mouse button as you move the pointer.Right-clicking; Press and release the right mouse button. Using the mouse involves five techniques:Variant of a MouseNow a days, we get varieties of mouse with different technologies in the market.Although, we have switched to Touchpads in Laptops, "the function of mouse is easy and user-friendly when compared with touch pads for a new user", says the users. Mostly all the applications are operated with mouse for easy working. In recent days, the optical mouse had overcome the old ball mouse, because of its 'easy to use' function. Variants of the MouseTrackballsTrack padsIntegrated Pointed Devices Variants of the Mouse - TrackballsA trackball is like a mouse turned upside-down.Use your thumb to move the exposed ball and your fingers to press the buttons.Many styles of trackball are available.With the ball-rolled Mouse, the movement of the pointer in the computer  is decided by the ball inside the mouse. If the ball gets damaged, or if dust gets clustered, the operation of the mouse becomes problem. When dust gathers, it takes some time to clear it too. With these disadvantages, the ball mouse was slowly moved away form the computer technology leaving the optical mouse to fill its space. Disadvantage of a BALL MouseVariants of the Mouse - TrackpadsA trackpad is a touch-sensitive pad that provides the same functionality as a mouse.To use a trackpad, you glide your finger across its surface.Trackpads provide a set of buttons that function like mouse buttons.Peter Norton'sIntroduction to ComputersVariants of the Mouse-Integrated Pointing DevicesAn integrated pointing device is a small joystick built into the keyboard. To use an integrated pointing device, you move the joystick.These devices provide a set of buttons that function like mouse buttons Other Types of MouseOptical mouseLight shown onto mouse padReflection determines speed and directionRequires little maintenance3A-48Now, almost everyone tries to switch from ball/roller mouse to Optical mouse. As the cost of the mouse is also being decreasing, the replacement is quiet quicker. To connect this optical mouse, the necessity is PS/2 or USB plug, and windows, Macintosh or LINUX operating system installed in the computer. The main components of the optical mouse are:Inbuilt optical sensor High speed camera which can take 1000 pictures at a time LED Working of Optical MouseOptical mouses do have an inbuilt optical sensor. The optical sensor reads the movements of the optical mouse (moved by the user) with the help of the light rays which comes out from the bottom. ( The area in which a light glows). When the user moves the optical mouse, the LED (Light Emitting Diode) present inside the mouse emits the light according the minute movements. These movements are send to the camera as light rays. The camera captures the difference in light rays as images. When the camera captures the images, each and every pictures and compared to one another with the digital technology. With the comparison, the speed of the mouse and the direction of the movement of the mouse are rapidly calculated. According to the calculation, the pointer moves on the screen. Working of Optical MouseOptical MouseOptical mouseComparison between a roller/ball  mouse and optical mouseThe optical mouse does not have any movable parts as of the ball mouse. So, the life of the optical mouse is long compared to the ordinary mouse. The optical mouse can also function good without a mouse pad, which is impossible with ordinary mouses. Any way, optical mouses cannot be used above reflecting glasses or any glass materials.Since the ball is absent in the optical mouse, the weight of the optical mouse is less than that of the ball mouse. The dust clustering problem is abolished in the optical mouse as its parts are all static. Benefits of MouseBenefits are,Pointer positioning is fastMenu interaction is easyUsers can draw electronically3A-53ERGONOMICS The science of designing equipment and workspace for a comfortable and safe working environment.REPETITIVE STRESS INJURIESRepetitive Stress Injuries can occur when someone performs a task repeatedly causing the build-up of irritating waste products in the muscles.Carpal Tunnel SyndromeCarpal tunnel is a passage in the wristHolds nerves and tendonsProlonged keyboarding swells tendonsMany professions suffer from RSICARPAL TUNNEL SYNDROMEWHAT IS CTS? It is the entrapment of the median nerve in the carpal tunnel. CTS occurs due to the swelling of the median nerve or the tendons of the wrist.WHAT CAUSES CTS? It occurs from using the computer for hours without proper body posture and improper techniques.WHAT ARE THE SYMTOMS OF CTS? Pain-Tingling-numbness in the thumb, index, and middle fingers—weakness and swelling of the wrist and hand.Carpal Tunnel Syndrome3A-57DeQuervain’s DiseaseDeQuervain’s Disease is an overuse injury of the thumb extensor tendons. It often occurs from repetitive tapping of the space bar.How Keyboard Cause Injuries?The continuous use of any keyboard may cause serious injuries. It can cause strain to hands, wrists, arms, neck or back. The risks of injuries can be reduced by taking frequent short breaks to get up and walk around a couple of times every hour.The chair height and keyboard tray should be adjusted so that the wrists are straight, and the wrists should not be rested on sharp table edges.3A-59Keyboard Strain3A-60ERGONOMIC TIPSTop 1/8 of monitor should be at eye levelElbows & knees should be positioned at 90-110 degreesSit up straight, but relaxedSit at least 24 inches away from the monitorWrists should be in a neutral position while typing or using the mouseTake “frequent” breaksAvoid glare on the computer screenErgonomics and Input DevicesOffice hardware suggestionsOffice chairs should haveAdjustable armrests and heightArmrestsLower back supportDesks should haveHave a keyboard trayKeep hands at keyboard heightPlace the monitor at eye level3A-62CorrectPosition ofusing a computer system3A-63Ergonomic style KeyboardPracticalWindows Keys CombinationsF1: HelpCTRL+ESC: Open Start menuALT+TAB: Switch between open programsALT+F4: Quit programSHIFT+DELETE: Delete item permanentlyWindows Logo+L: Lock the computer (without using CTRL+ALT+DELETE)Windows program key combinationsCTRL+C: CopyCTRL+X: CutCTRL+V: PasteCTRL+Z: UndoCTRL+B: BoldCTRL+U: UnderlineCTRL+I: ItalicGeneral keyboard-only commandsF1: Starts Windows HelpF10: Activates menu bar optionsSHIFT+F10 Opens a shortcut menu for the selected item (this is the same as right-clicking an objectCTRL+ESC: Opens the Start menu (use the ARROW keys to select an item)CTRL+ESC or ESC: Selects the Start button (press TAB to select the taskbar, or press SHIFT+F10 for a context menu)CTRL+SHIFT+ESC: Opens Windows Task ManagerALT+DOWN ARROW: Opens a drop-down list boxALT+TAB: Switch to another running program (hold down the ALT key and then press the TAB key to view the task-switching window)SHIFT: Press and hold down the SHIFT key while you insert a CD-ROM to bypass the automatic-run featureALT+SPACE: Displays the main window's System menu (from the System menu, you can restore, move, resize, minimize, maximize, or close the window)General keyboard-only commandsALT+- (ALT+hyphen): Displays the Multiple Document Interface (MDI) child window's System menu (from the MDI child window's System menu, you can restore, move, resize, minimize, maximize, or close the child window)CTRL+TAB: Switch to the next child window of a Multiple Document Interface (MDI) programALT+underlined letter in menu: Opens the menuGeneral keyboard-only commandsALT+F4: Closes the current windowCTRL+F4: Closes the current Multiple Document Interface (MDI) windowALT+F6: Switch between multiple windows in the same program (for example, when the Notepad Find dialog box is displayed, ALT+F6 switches between the Find dialog box and the main Notepad window)General keyboard-only commandsGeneral folder/shortcut controlF4: Selects the Go To A Different Folder box and moves down the entries in the box (if the toolbar is active in Windows Explorer)F5: Refreshes the current window.F6: Moves among panes in Windows ExplorerCTRL+Z: Undo the last commandCTRL+A: Select all the items in the current windowBACKSPACE: Switch to the parent folderSHIFT+click+Close button: For folders, close the current folder plus all parent foldersNOTEPAD – Create New NotepadSave/Save As/ Open/Print NotepadChange Font /TypeSummaryIn Today’s Lecture, we have learntKeyboard, history and different styles of modern keyboardMouse, Different types of mouseErgonomicsWindows Keyboard commandsNotepad practical THE END