ICT - AS - INFO 1 - TOPIC 1 -INPUT

Input

Data types

• Text

• images

• moving images

• numbers

• sounds

Manual input

• Have to physically input all data

• Keyboard:

  • Typically QWERTY

  • has keys for each letter, as well as special keys i.e. ESC

  • The layout of the keyboard varies from country to country

  • Ergonomic keyboards have been created to reduce injuries such as RSI (repetitive strain injury)

  • The downfall of ergonomics is people being reluctant to change to it from a regular keyboard.

  • Mobile devices have smaller keyboards called keypads, since a full sized keyboard would not be practical.

• Mouse:

  • Most common pointing device

  • Connected via a cable or wirelessly

  • Two different types, optical and mechanical

  • A mechanical mouse has a rolling ball which senses movement on a flat surface

  • An optical mouse uses a light sensor to detect motion

  • Most mice will have 2-3 buttons

  • A trackball, is like a mouse by has a ball on the surface not underneath, the ball is moved using the fingers or the palm

  • Laptops usually have a trackpad

  • A trackpoint is a small button that works like a joystick

• Touch-sensitive devices rely on touch for data input

• Concept Keyboard:

  • Divided into areas to fit the purpose

  • Special software is required to interpret the keys pressed

  • useful at check outs and restaurants, to simplify paying, clicking on an icon or word rather than remembering a price

  • Often covered in plastic film to protect it from getting dirty

  • Also used as input for those with disabilities

• Touch screens:

  • Senses when an area of the screen is being touched, using embedded wires or infra-redlight beams.

  • Special software is needed to interpret the signals

  • Often used in public areas because they are easy to use and combine input and output.

  • A finger or a stylus can be used to select items, draw or write.

  • Often there is software that can convert written text into characters, and it can be trained to recognise the handwriting of a particular user.

• Graphics Tablet:

  • Also known as digitizing tables

  • Used mainly for drawing

  • A stylus draws on a flat plate

  • More natural than using a mouse

  • An example is an interactive whiteboard that can be written on using pens and allows for objects to be moved around the screen using fingers.

• Speech Recognition:

  • Involves the user speaking into a microphone

  • Words are compared to a sound dictionary and converted into readable text

  • Not very reliable due to different voices and accents

  • Complicated by words that sound the same but mean different things i.e there, their and they’re.

  • Functions better if each word is said separately and clearly but this makes the process last longer.

Automatic Input

• Input devices that read data from media that already have data stored on them. This can either be stored magnetically or on paper and then interpreted.

• Credit Card reader:

  • two main ways of storing data, a magnetic ***** card or a smart card ( Chip-and-PIN)

  • Magnetic ***** cards are swiped through a reader,…