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# Input Devices ## Alphanumeric Keyboards - An alphanumeric keyboard contains letters, numbers and symbols in particular layouts. - This keyboard, which is modelled on the typewriter keyboard, is known as a QWERTY keyboard (based on the sequence of letters at the top left). - As each key is press...

# Input Devices ## Alphanumeric Keyboards - An alphanumeric keyboard contains letters, numbers and symbols in particular layouts. - This keyboard, which is modelled on the typewriter keyboard, is known as a QWERTY keyboard (based on the sequence of letters at the top left). - As each key is pressed, a unique digital code is sent to the computer. - For example, the code 01100001 is produced when the 'a' key is pressed and the code 1100010 is produced when the letter 'b' is pressed. ## Connecting Keyboards to a Computer Keyboards can be attached to a computer in the following ways: - With a cord connected to a USB port - Wirelessly through radio frequency or WiFi signals - On-screen, where the keyboard appears on the computer screen - Built-in, where the keyboard is part of the computer, (for example, a laptop) ## Ergonomics - Users who spend long hours on the keyboard may prefer to use an ergonomic keyboard, which is a standard keyboard designed for greater comfort and usability. - Similarly, a person who plays computer games may prefer to use a gaming keyboard. - These keyboards include programmable keys so that gamers can customize the keyboard to the game being played. ## Special-Function Keyboards - Special-function keyboards are designed for a particular purpose. - Examples include the following: ### The Braille Keyboard - The Braille keyboard has its keys marked with raised dots to help users who are blind. - Users can type and enter text or instructions for the computer by feeling the Braille symbols on the keys. ### The Eye-Controlled Keyboard - The eye-controlled keyboard, which was designed mainly for people with physical disabilities, lets a user enter information by focusing their eyes on individual keys on the keyboard displayed on the screen. - Letters, numbers, symbols and function keys are all accessible. ### The Concept Keyboard - The concept keyboard contains a flatbed of contact switches covered by a flexible membrane. - Whole words, pictures or symbols are superimposed over each contact switch, to which the computer is then programmed to respond appropriately. - These keyboards are used in education as an early-learning aid, in restaurants so the operator can visually add up the cost of standard menu items, and in places where a normal keyboard would be at risk. # Did you know? - The traditional keyboard known as the QWERTY keyboard, which is still widely used today, was patented in 1867 and was designed to slow down the speed of typists so that the typewriter keys would not jam. - Do research to find out about another keyboard design that allows for faster typing and less errors, but is not being manufactured.