Hardware Input

Input Devices

•Any items of hardware that allow entry of information into the computer

Information = images, sound, movements, text

Some input devices are specially designed to help users with disabilities to use the computer (equality of access)

Keyboards

• Typical keyboard = QWERTY

• Dvorak keyboards - use a completely different layout which is claimed to increase typing speed by rearranging commonly paired letters

Keyboards

• QWERTY alternatives:– Multimedia - standard keyboards with additional “hot

keys” for opening web browsers or media players– “windows” key on a PC– “Fn” key

Keyboards

• Concept keyboards– Each key is

programmed to perform a custom function

• For example, used in restaurants - each key represents a different menu item

Keyboards

• Soft keyboard– (also called software keyboard, onscreen keyboard, or

virtual keyboard) – A keyboard represented by a series of buttons drawn on a

monitor or screen– Options are selected by using pointer devices (mouse,

touch screen)

Keyboards

• Soft keyboard– Useful because they can be more accessible

• Keys can easily be increased for users who have difficulties with small keys

• Keyboard language can be changed easily• Useful for small devices such as phones and PDAs where it isn’t

possible to include full-sized keyboards or no keyboards at all• Soft keyboards in security conscious environments: some banks use

them on the login pages of their online banking web sites to reduce the risk of key logging attacks

Mice

• Mouse– The standard pointing device on most desktop

computers• Two buttons and a scroll wheel in the center• Additional buttons on the side or in the middle can be

customized for gaming functions

• Trackball– A relatively large ball which is fixed in place so that the

user can spin it around, controlling a pointer on the screen

• Advantage: can be used in small places, because they don’t move across the desk

• Handicapped who can’t move a mouse can more easily operate a trackball since it only requires a thumb or fingers

• Touch pads– Common devices on laptops, where there is not

enough room for a mouse– Multi-touch pads - use several fingers

Touchscreen

• Allows users to interact with computers using computers using their hand or a specially designed pen called a stylus

• Useful on small portable devices

• Useful in airports for check-in, self-service photo kiosks, ATMs

– Multi-touch - used in many mobile phone operating systems

• Being able to control the device using a single finger or making complex gestures using multiple fingers

• Microphones

– Allow sound data to be input into the computer

• Many laptops have microphones built in to them, and external microphones can also be used

– Microphones are often used with video-conferencing and Voice-over IP (VoIP) software

• VoIP lets users talk - often with video too - between two computers over the Internet for much less than the cost of a phone call

Microphones

• Voice recognition software– Recorded sound is a collection of digital data that cannot be recognized except through

this software• The software allows a person to dictate words into a word processor to write a document,

rather than typing– How it works:

» Software breaks down the recorded sound into parts» Software tries to match the parts with the sounds of letters and words» Software produces the corresponding character on the screen

• Voice-control software– The user speaks commands into the computer operating system

• “Open this program”

– Disadvantages: in busy, noisy environments, not effective– Advantages: those with disabilities

Game Controllers

•Joysticks and game pads - game input devices

•Wii - the controller is held in the hand in mid-air, and internal motion sensors interpret the user’s movement into actions in the game

–The user holds the controller and moves, and the character onscreen mimics the movements

Barcode Scanners

•Use a laser to shine light onto a barcode label–The thickness of the lines and the spacing between the lines on the barcode determine the amount of reflected light–This is then interpreted as a number by the barcode scanner

•Most commonly used in grocery stores•UPC (Universal Product Code) is one standard which defines how a barcode stores its information

Magnetic Stripe Readers

–Bank cards, credit cards, hotel key cards feature a magnetic stripe on the reverse side

•Magnetic stripes store a small amount of data which is read using a magnetic stripe reader

–Disadvantages: it is possible to purchase stripe writers to alter the data on such cards, which can create a clone of an existing bank card which might be indistinguishable from a genuine card.

Smart Cards

•Plastic credit card style cards that differ from magnetic stripe cards by having a higher storage capacity and an embedded processor

–The processor is powered on when the card is inserted into a smart card reader–The processor then controls access to the data stored on the card–This allows the data to be encrypted for increased security

•Bank and credit cards are frequently smart cards•Some governments issue smart cards as identity cards, which can also be used for authentication when claiming services like health care or voting

–Smart cards usually contain a unique identification number which can then be used to access a database for further details related to the card

Optical Mark Recognition

•OMR - an input method for speedily reading and counting multiple choice style answer papers

–Uses reflected light to determine whether or not a mark exists in a box on a piece of paper, and then tallies the results

Magnetic Ink Character Recognition

•A specialized technology that uses ink containing iron particles, making it magnetic

–MICR text is written in a special font, making it readable by humans, while the varying amounts of iron allow the computer to read them

•Most commonly found in checks

Scanner

•A device for digitizing a piece of paper•A digital image of the paper scanned is stored as a standard image file (jpeg, tiff, png)•The resolution of the scanner, measured in DPI (Dots per Inch), determines the quality of the image produced

•OCR - optical character recognition - software to convert a scanned image containing text back into normal text that can be edited in a word-processing program

–OCR software doesn’t work well with hand-written text

Digital Cameras

•A useful way of inputting image, video and sound straight into a computer

–Done using a USB or FireWire connection, or by putting the camera’s memory card into a card reader in the computer

Digital Cameras

Web Cams

•Relatively low resolution video cameras–Many laptops have web cams built into their screens–Web cams are normally used to record the computer user, often for video conferencing

Radio Tags

•Used for locating or tracking objects–Emit very high frequency (VHF) radio signals that can be picked up and located by a receiver

•Used to track wildlife•GPS - radio tags can also be used in combination with GPS to generate alerts if tagged animals enter certain areas, such as farm land

Radio Frequency Identification (RFID)

•RFID - consists of an RFID tag attached to the surface of an item, or inside it and an RFID reader to query the tag and retrieve its information

–Greater storage capacity than barcodes and are contactless - the reader does not have to be very close to the tag and it doesn’t require line of sight to the tag

•In grocery stores, allows pallets of toods to be tagged as they leave the manufacturer and go to the warehouse, then to the shelf•Used in pat tags implanted into their skin and containing information•Passports which will allow biometric data to be stored

Radio Frequency Identification (RFID)

•Concerns about RFID–Privacy: tags can be made as small as a grain of rice and embedded within objects, and the reading range is really far–They could be used to track an item and the customer’s track through the store, then this data could be compiled