CSC 101 Introduction to Computing Lecture 4

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CSC 101 Introduction to Computing Lecture 4. Dr. Iftikhar Azim Niaz Last Lecture Summary I. Parts of the Computer System Hardware Software Data People Information Processing Cycle Input Processing Output Storage. Last Lecture Summary II. Computer Hardware - PowerPoint PPT Presentation

Text of CSC 101 Introduction to Computing Lecture 4

Lecture 3

CSC 101Introduction to Computing

Lecture 4

Dr. Iftikhar Azim Lecture Summary IParts of the Computer SystemHardwareSoftwareDataPeopleInformation Processing CycleInputProcessingOutputStorage

23Last Lecture Summary IIComputer HardwareProcessor, Memory, MotherboardInput DevicesOutput DevicesCommunication devicesStorage DevicesMagnetic storage devices, Floppy Hard diskOptical storage devices, CD, DVD, Blu RayComputer SoftwareSystem software and Application softwareComputer Users

34 Using the input devicesCPU is computer brain the input devices are its sensory organsFrom user point of view, input device are importantEnables user to enter information and commands into the computerTwo common input devicesKeyboard Mouse

4Input DevicesHardware used to enter data and instructions5

56 Two Common Input DevicesKeyboard


6The KeyboardFirst peripheral to be used with computersThe most common input device for inputting text and numbersAbout 100 keysMust be proficient with keyboardSkill is called keyboarding7Standard Keyboard LayoutIBM Enhanced Keyboard with 101 keys8

Five Groups of KeysAlphanumeric KeysModifier KeysNumeric KeypadFunction KeysCursor Movement keys


Alphanumeric KeysArea of computer that looks like a typewriterSometimes called QWERTYKeys having specific functionsTabCaps LockBackspaceEnter


Modifier KeysShiftAlt (Alternate)Ctrl (Control)Modify the input of other keys12

Numeric Keypadusually located on the right side of the keyboard, Has 10 digits and mathematical operators (+, -, *, and /). also features a NumLock keyOn - forces the numeric keys to input numbers. Off - perform cursor movement control and other functions.13

Function Keyslabeled F l, F2, and so on in a row along the top of the keyboard.allow you to input commands without typing long strings of characters or navigating menus or dialog boxes.Each key's purpose depends on the program you are using. Many programs use function keys along with modifier keys to give the function keys more capabilities.

14Cursor Movement Keyslet you move around the screen without using a mouse. Cursor is a mark on the screen indicates where the characters you type will be enteredArrow KeysHome and EndPgUp and PgDn15

Special Purpose KeysEsc (Escape)InsertDeletePrtSc (Print Screen)ScrLk (Scroll Lock)PauseTwo special for Microsoft Windows StartShortcut 1617

Internet and Multimedia ControlsOne of the latest trends is the addition of Internet and multimedia controls. Microsoft's Internet Keyboard and MultiMedia Keyboard, e.g. you can use the buttons to launch a Web browser, check e-mail and start your most frequently used programs. Multimedia buttonscontrol the computers CD-ROM or DVD drive adjust the speaker volume18

How Keyboard WorksKey is pressed on keyboardKeyboard controller detects a key pressKeeps the code in its memory, Keyboard bufferCode represents the key pressedController notifies the operating system via an interruptOperating system responds the interrupt by the reading the code from bufferOS passes the code to CPU1919Teaching tipTable 5A.3 presents the ASCII code. An exercise that never fails to amuse students is to use the Alt and the number pad to enter letters into an application. As before, open MS Word. Have students hold down the Alt key and type an ASCII value into the number pad. Once they release the Alt, the letter appears. This is a useful skill when the keyboard breaks. Challenge the students to explore numbers above 128. Dvorak KeyboardsFor people who type with one hand or fingerReduce the amount of motion required to type common English textIncrease typing rateReduced errorsBut Qwerty is still popular20Dvorak Keyboards

Both HandsLeft Hand

Right Hand Keyboard Layout

Latham Sholes' 1878 QWERTY keyboard layout22Non-standard layout and special-useChorded keyboard

Software or virtual keyboard

Foldable keyboard

Projection (as by Laser)23Chorded KeyboardAssociate actions with combinations of key pressesAs many combinations available, chorded keyboards can effectively produce more actions on a board with fewer keysCourt reporters mostly use them24

Software or Virtual Keyboardsis a software component that allows a user to enter characters. usually be operated with multiple input devices,Touch screen, Actual keyboard and Mouse.25

Foldable Keyboardsmade of soft plastic or silicone which can be rolled or folded on itself for travelWhen in use, these keyboards can conform to uneven surfaces, and are more resistant to liquids than standard keyboards. connected to portable devices and smart phones. 26

Projection Keyboardproject an image of keys, usually with a laser, onto a flat surface. The device then uses a camera or infrared sensor to "watch" where the user's fingers moveProjection keyboards can simulate a full size keyboard from a very small projector. 27

Wireless Keyboardprovides increased user freedomincludes a required combination transmitter and receiver unit that attaches to the computer's keyboard port. The wireless aspect is achieved either by radio frequency (RF) or by infrared (IR) signals sent and received from both the keyboard and the unit attached to the computer. A wireless keyboard may use an industry standard RF, called Bluetooth. 28The MouseAll modern computers have a variantAllows users to select objectsPointer moved by the mouseMechanical mouseRubber ball determines direction and speedThe ball often requires cleaningOptical mouseLight shown onto mouse padReflection determines speed and directionRequires little maintenance29The Mouse

mouse buttonswheel buttonball

3030Optical Mouse

31 Benefits of Using MousePointer positioning is fast

Menu interaction is easy

Users can draw electronically32Interacting With a MouseActions involve pointing to an objectClicking selects the objectDouble clicking the objectClicking and holding drags the objectReleasing an object is a dropRight clicking activates the shortcut menuModern mice include a scroll wheel3333Insider informationDouglas Englebart patented the first mouse in 1970 as the X-Y position indicator for a display system. The name mouse comes from the tail on the device. Mouse Button ConfigurationConfigured for a right-handed userCan be reconfigured for left handedBetween 1 and 6 buttons Extra buttons are configurable

34Cordless Keyboard and MouseCommunicate with a receiver attached to a port on the system unitUse infra-red (IR) or radio frequency (RF) technology

3535Variants of the MouseTrackballsUpside down mouseHand rests on the ballUser moves the ballUses little desk spaceMostly two buttonsCan be configured for bothright-handed and Left-handed use

36Track PadsStationary pointing deviceSmall plastic rectangleFinger moves across the padPointer moves with the pointerPopular on laptops

3737Track PointTrack pointLittle joystick on the keyboard between G, H & B keysMove pointer by moving the joystickTwo buttons beneath Spacebar same as mouseSave great of time and effort

3838Insider informationThe term track point is copyrighted by IBM. 39SummaryStandard input devicesStandard KeyboardFive groups of KeysHow Keyboard works ?Dvorak KeyboardNon standard layout and Special UseThe MouseFive Techniques of using MouseVariants of Mouse

39Recommended Websites