Cambridge International AS and A Level Applied 9713.

The standard QWERTY keyboard is the commonest way to enter text andnumerical data into a computer.

Each individual key is a switch, which when pressed, sends a digital code to the computer.

For example, pressing the 'A' key produces the binary code 01100001representing the lower case letter 'a'. Holding down the shift key at the same time produces the binary code01000001 representing the upper case letter 'A'

advantages

• Reliable for data input of text and numbers.
• Usually supplied with a computer so no additional cost.
• Specialised keyboards are available.

disavantages

• Users may be slow for not very accurate typists.
• Slow for accessing menus etc. and difficult to use if you want to move objects around the screen.
• Difficult for people unable to use keyboards through paralysis or muscular disorder.