Input Devices | Keyboard And Mouse

Keyboard

The keyboard is the most common input device used with personal computers to pass information to the central processing unit. It is used for keying in data and codes into computer memory. It consists of the following parts.

Alphanumeric keys (typewriter keys)

Consists of alphabetical keys labeled from A to Z and numeric keys labeled from 0 – 9. Sometimes they are referred to as typewriter keys because their arrangement exactly resembles that one of a typewriter.

Cursor movement pointer keys

Consists of four keys each one having an arrow pointing different direction (up, down, left and right). They are used to move cursor sideways to all directions. Each key moves the cursor towards the direction it is pointing.

Enter Key

Used to execute commands at the prompt, that is when a command is typed then enter is pressed and the command is executed at once. It also helps in ending lines while typing in a word processor. It can as well be used to execute commands found on menu options after highlighting them.

Function Keys

Label from F1 to F12. Their uses depend on the programme you are using. For example in word perfect F3 is for help while in lotus 123 F1 is for help.

Backspace and Delete

Are for erasing/deleting characters. Backspace delete characters to the left of cursor while delete key delete characters from right of the cursor.

Space bar

Create space between words.

Page Up

Moves the cursor one page up.

Page down

Moves the cursor one page down.

Mouse

A mouse can be used to control the pointer on the screen and it usually has one or more buttons on top.

The left mouse button is the one that is most commonly used for selecting text or graphics on screen.

Pressing the right mouse button displays a shortcut menu containing commands that are relevant to the item that is selected.

Using A Mouse

Left mouse click

A single click on the left-hand button will insert the I-beam into the text or select an icon or graphic. A double click on the left-hand button will open a file or select a word for editing.

Point-click-drag

Using the left-hand button will select a menu item, select and move a graphic, create elements in a graphics program or select a range of text.

Right mouse click

When the right-hand mouse button is clicked a shortcut menu appears containing commands that are specific to the item that is selected. Clicking away from the menu closes it.

Pointers

The pointer can change shape depending on the task being performed.

Pointer:

This type of pointer enables you to select menu items, files, icons, graphics etc.

I-beam:

This type of pointer enables you to select, insert or edit text.

Crosshair:

This type of pointer is used to draw lines, boxes, circles etc.