Input devices are hardware components or peripherals that are used to enter data or feed the computer with data for processing. Input devices are also used to send command signals or controls to the computer. Input devices take data and programs in the form people can read or understand, and convert them into a form consisting of machine-readable electronic signals of ‘0’s and ‘1’s which the computer can work with.
Input devices can be grouped into:
- Keying/text input devices
- Pointing input devices
- Source data entry input devices
- Audio and video input devices.
In this post we take look at the Keying/Text Input Devices.
Keying/Text Input Devices
As a class of input devices, keying input devices possess keypads with labelled keys used for typing. The most popularly used keying input device for the computer is the keyboard. The computer keyboard is used to enter data and send command signals into the computer. Though it has almost the same setting as the typewriter keyboard, the modern computer keyboard has more keys than the typewriter. It has a combination of a typewriter keyboard and a numeric keypad. Moreover, it has additional special-purpose keys.
The keyboard comes with several basic designs but the traditional design or straight design is mostly used with desktop computers. All desktop computers are virtually used with either a wired (cable) or wireless keyboard. Standard keyboards for personal computers come in different styles or layouts. Most keyboards are laid out identically but various models differ in size, shape and feel.
The QWERTY keyboard is the most popularly used. It is named after first six letters on the top row line of the keyboard layout.
QWERTY keyboard layout
A keyboard with an alternative layout, the DVORAK keyboard was designed to improve typing speed. The DVORAK keyboard designed by August Dvorak has frequently used keys placed in the middle of the typing area. Special DVORAK keyboards are available for computer systems but they are not standard equipment.
The most common keyboard layout in use is the Enhanced Keyboard (or US traditional) which has at least 101 keys arranged in groups. There are five groups of keys that can be identified on the enhanced and windows (104-key) keyboard. These are:
- The Alphanumeric keys
- The Function keys
- The Numeric keypad
- Modifier keys
- Cursor Control or Navigation keys
These are a set of keys that form the main typing keys which is a combination of alphabets, numbers, and symbols. They also include special keys used for performing specific, control and functions. These special keys are the Tab key, Caps Lock key, Backspace key and the Enter key.
There are 12 Function keys and they are those labelled F1, F2, F3… F12. The Function keys are usually arranged in a row along the top of the keyboard. They are used to input commands which would have required typing of long strings of characters or navigating menus or dialogue boxes. Each Function key depends on the program being used. For example in most programs the F1 key is the help key.
The Numeric Keypad
The numeric keypad is usually located at the right side of the keyboard with ten digits and the mathematical operators (+,-,*, / and.). The numeric keypad also features the Num Lock key which works like the Caps Lock key in the alphanumeric key group.
Modifier keys are special keys that are used to modify the normal input of other keys, when the two are pressed in combination. The modifier keys are the Shift key which when pressed in combination with an alphanumeric key, produces an output of a capital letter or symbol; Control (Ctrl) key produces different results depending on the program in use, for example in Windows Ctrl-key combinations provide shortcuts for menu commands; Alternate (Alt) key operates like the Ctrl key except that it produces a different set of results, for example in Windows Alt-key combinations enable you to navigate menus and dialogue boxes without using a mouse.
The Cursor Control or Navigation Keys
These allow you to move the cursor or the insertion point around the screen. Most keyboards include the Arrow keys as standard cursor movement keys. Each of the four Arrow keys moves the cursor up, down, left or right one character space. The Page Up and Page Down keys, scroll the page up and down. The Home key is used to return the cursor to the beginning of the line while the End key puts the cursor at the end of the line. The Insert key is mainly used to switch between overtype mode, in which the cursor overwrites any text that is present and the Delete key discards the character ahead of the cursor’s position.