What is peripheral?
v Devices that connects to a system unit and is controlled by the Central Processing Unit (CPU) in the computer
• What is input ?
• Any data or instructions entered into memory of computer
What are the two types of input?
Ø Unprocessed text, numbers, images, audio and video
Ø User responses
• What are input devices ?
• Input devices is any hardware component that allows an user to enter data or instructions into a computer
The categories of input devices:
• The keyboard
• Pointing devices
• Scanners and
• Input devices for the physically challenged users
• What is a keyboard?
• An input device that contains keys, users press to enter data into a computer system.keyboard Converts letters, numbers and other characters into electronic signals that are machine-readable.
It is a 8-bit code (ASCII-8) or able to accommodate 256 different
• Desktop computer typically have from 101 to 105 keys
• Required by software with Command Line Interface (CLI)
• How is the keyboard divided?
• Typing area
• Numeric keypad
• Function keys, special keys that issue command
- The types of keyboards:
v Enhanced keyboard
v Wireless keyboard
v Portable keyboard
v Laptop keyboard
v Handheld keyboard
v Ergonomic keyboard
v Virtual keyboard
v QWERTY keyboard
v The most widely used type of keyboard, so named because the first letters on the top alphabetic line spell QWERTY
v DVORAK keyboard
v A type of keyboard that places frequently types letters in the middle of the typing area
v A keyboard that has 12 function keys along the top : 2 Control (CTRL) keys and 2 Alternate (ALT) keys along the bottom and a set of arrow keys and other additional keys between the typing area and the numeric keypad
Wireless or Cordless keyboard
v Battery-powered keyboard that transmits data using wireless technology, such as radio waves or infrared light waves
• Portable keyboard
• A full sized keyboard, that an end-user conveniently can attach or remove from a handheld computer or PDA
• Laptop and Handheld keyboard
• Notebook and many handheld computers have built-in keyboards
- Ergonomics keyboard
v Design to minimise strain on hands or wrists
v Ergonomics incorporates comfort, efficiency and safety into design of items of workplace
• Virtual keyboard.
Projects infrared image of keyboard onto any flat surface
• What is a pointing device?
v An input device that allows the user to control a pointer on the display screen
v Required by software with Graphical User Interface (GUI)
• The types of pointing devices
• Pointing stick
• Joystick and Wheel
• Light pen
• Touch screen
• Stylus or Digital pen
• What is a Mouse ?
• Pointing device that fits under palm of hand
• Pointing device controls movement of pointer, also called mouse pointer
• A pointer on screen takes several shapes
The types of pointing devices :
• Mechanical mouse
• Optical mouse
• Cordless mouse
• How does a mechanical mouse work ?
• Rubber or metal ball is on its underside
• Movement of mouse translates into signals that computer understand
• How does an optical mouse work ?
• Senses light to detect mouse’s movement
• More precise than mechanical mouse
• Connect using a cable or wireless
• Wireless or Cordless mouse
• What is a trackball ?
• Stationary pointing device with a ball on its top
• To move pointer, rotate ball with thumb, fingers or palm of hand.
What is a Touch pad?
• Touch pad is small, flat, rectangular pointing device that is sensitive to pressure and motion. It Often used in laptop computers.
• What is a pointing stick?
• Pointing stick is pointing device shaped like pencil eraser positioned between keys on keyboard
• Moves pointer as pressure is applied
• Often used in laptop computers
• What are a joystick and a wheel?
• Is vertical lever mounted on a base
• It enables the user to move within the screen’s environment
• Widely used in computer games industry
• Wheel is steering-wheel-type input device
• Users turn the wheel to simulate driving a car, truck etc.
• Most wheels also include foot pedals to simulate car brakes and accelerator
• What is a light pen?
• Handheld input device that can detect light
• Press light pen against screen surface and then press button on pen
• What is a Touch screen ?
• Monitor has a touch-sensitive panel
• Touch areas of screen with finger
• Used to issue simple commands or choose from a list of options
• Often used with kiosk
• What is a stylus or digital pen ?
• Looks like a ballpoint pen, but uses pressure to write text and draw lines
• What is an Electronic signature ?
• Is a legal signature created using special software, stylus and graphics tablet
• Also called as e-signature
• What is a scanner ?
• Light-sensing device that captures data directly from source document
• Source document is original form of data (printed text or graphics)
• Used for image processing, converting paper documents into electronic images
• What is an optical reader?
• Device that uses light source to read characters, marks and codes and then converts them into digital data
• What is an OCR font?
• OCR device determines characters’ shapes by detecting patterns of light and dark
• OCR software converts shapes into characters the computer can understand
• What is a turnaround document?
• It is a document that after being output by the computer can be used to record data and this data can then be input to the computer using a document reader
• Portion you return has information printed in OCR characters
• What is an Optical Mark Recognition (OMR) ?
• Reads hand-drawn pencil marks such as small circles or rectangles
• Used for ballots, enrollment application, attendance, questionnaires, course evaluation and multiple choice tests and examination
• What is a Bar code?
• Identification code that consists of a set of vertical lines and spaces of different widths
• The symbol of the Universal Product Code (UPC)
- What is a Bar code scanner?
v Uses laser beam to read bar codes
- What is a Magnetic-Ink Character Recognition (MICR) reader?
v Can read text printed with magnetized ink
v Banking industry almost exclusively uses MICR for cheque processing
• What is Biometrics?
• Authenticates person’s identity by verifying personal characteristic
• Fingerprint scanner captures curves and indentations of fingerprint
• Hand geometry system measures shape and size of person’s hand
• What are examples of Biometric technology?
• Voice verification system compares live speech with stored voice pattern
• Signature verification system recognizes shape of signature
• Iris recognition system reads patterns in blood vessels in back of eye
• Biometric data is sometimes stored on smart card, which stores personal data on
microprocessor embedded in card.