The Computer Keyboard
The keyboard is the main input device to the computer. It is used to enter commands and data. The keyboard is divided into various sections of keys, which can be summarized as follows:
The alphabet, numbers and various symbols. e.g. * ( ^ y j £ #) Some keys have more than one character on them, one above the other. These are generally punctuation and mathematical symbols. These characters are obtained by pressing and holding down the SHIFT key before pressing the required key. Capital letters are also obtained in this way. For continual uppercase characters you can use the CAPS LOCK key. Press this key once to type in uppercase continuously. Press it again to release it. the SHIFT and CAPS LOCK key is shown below.
The long bar across the bottom of the keyboard is the space bar. Press once to insert a space to the right.
The function keys are located at the top of the keyboard and number F1 to F12. They are programmed to perform different functions within software applications.
The numeric keys along the top of the keyboard are repeated and grouped together at the right of the keyboard. This is to allow the speedy input of numerical data. The number keys can also be used as cursor control keys. The Num Lock key is used to activate and deactivate the numeric keypad. When Num Lock is engaged, the Num Lock light comes on and key presses on the keys of this group are interpreted as numbers. When it is not engaged the key presses are interpreted as Page Up, Page Down, and other cursor movement commands.
Cursor Control Keys
These keys are: Page Up, Page Down, Home, End, Each of these keys are featured twice on the keyboard, on the numerical keypad and as separate keys between the numeric keys and character keys. The directional arrows move the key up or down a line and one space to the right or left. The Home key moves the cursor to the top left hand corner of the screen. The End key moves the cursor to the last character in the current line or screen. The Page Up key moves the screen up in predetermined increments. The Page Down key moves the screen down in predetermined increments.
Specifically Defined Keys
This set of keys does not produce any printable characters. They are used to control editing and display activities.
This key has two functions. One is to move the cursor from one line to the next (as with a typewriter return key).The second is to enter a program command. In Linux, the Enter key terminates an entry sequence and lets the machine know that the letters typed so far constitute a command to be carried out.
While held down, this key activates the upper case letters and top half of various keys.
This key moves the cursor to the left by one position each time it is pressed. As it moves it erases any character it passes over.
This key removes characters from text at the cursor position.
This key does not have any function on its own. It is used in conjunction with other keys to carry out specific functions. To use, hold down the control key and press the key with the desired function.
Similar to a typewriter tab key. Used to set tab positions in a document. Setting tab positions allow the user to move the cursor to defined positions, for instance when typing columns of data.
Inserts characters in a line of text. The remaining text moves one cursor position to the right for each character inserted. If the key is not active, typing a character will result in that key overwriting the character at the current position of the cursor.
Department of computer science and information systems
University of limerick, limerick, Republic of Ireland
Department of Computer Science and Information Systems, University of Limerick, Limerick, Republic of Ireland