Computer Input Devices

Sections of the Keyboard

The Keyboard is divided into five sections;

Table of Contents

I. Alphanumeric keys( Alphabet and Numbers): consist of alphabet (a-z) and numbers (0-9)

II. Function keys F1-f12: they are twelve in number f1-F12 and are located horizontally on the first row of the enhanced keyboards. On standard keyboard they are labeled F1-F10

III. Control keys- Del, Ctrl, Esc and alt: These are used in line with other keys to instruct to perform specific task.

IV. Cursor –Control and screen movement keys-Arrow, home, end, page up etc.: it allows the user to move cursor to the left, Right, up online and down one line.

V. Numeric keypad: these are usually situated at the extreme right hand corner of modern keyboard. They have only numbers.

FEATURES OF KEYBOARD

1. Rollover Capability: The Keyboard has ‘Rollover’ capability, that is, several keys can be pressed almost simultaneously and they will be registered in sequence. They will not jam, Thus increasing the operators input speed.

2. Auto-Repeat Capability: Most of the keys on the keyboard have auto-repeat capability. When a key with this feature is depressed, it will keep on repeating the operation until it is released.

USES OF KEYBOARD

It is used to:

1. Enter text, numbers and punctuation

2. In the absence of the mouse, it can be used to shutdown the computer system.

3. Ctrl +Alt +Del keys can be used to restart the computer during warm booting.

MOUSE

Mouse, like the keyboard, is an interface through which we communicate with a computer screen. Mouse is used for drawing as well as potting images.

Mice are grouped into two

Ø Optical mouse

Ø Ball track mouse

BASIC Mouse functions

Clicking: Pressing and releasing a mouse button quickly at once

Double Clicking: Pressing and releasing of Mouse button twice in rapid succession

Dragging: Press of a mouse button by holding it down while taking the object away

Point: this means to move the mouse pointer so that it touches the item.

Functions of the mouse

1. It is used for drawing different kinds of object

2. It is used to select items, menu etc.

3. It is used in moving, cutting and pasting objects.

FEATURES OF COMPUTER MOUSE

1. It has right and left button

2. Mouse has scroll button

3. Presence of ball/laser underneath

To use the Mouse you need just two fingers; your right thumb and the third finger. Your first finger should be on the left button while the third finger should be on the right. These operations differ from laptops to laptops