Using the Keyboard And Mouse Chapter 2A Using the Keyboard And Mouse

The Keyboard The most common input device Must be proficient with keyboard Skill is called keyboarding A standard keyboard uses 100 keys

Keyboard The keyboard allows the computer user to enter words, numbers, punctuation, symbols, and special function commands into the computer’s memory.

The Keyboard The alphanumeric keys Includes letter, numbers, Tab, Caps Lock, Backspace, Enter.

The Keyboard The modifier keys Shift, Alt, Ctrl The numeric keypad 10 digits and mathematical operators, Num lock

The Keyboard The function keys Labeled as F1, F2 etc The cursor movement keys Arrow signs, Page Up, Page Down The special purpose keys Esc, Prt Sc

How keyboard works How the computer accepts input from keyboard Keyboard controller detects a key press Controller sends a code to the Keyboard Buffer Code represents the key pressed Controller notifies the operating system Operating system responds and read the code from Keyboard Buffer The system software passes the code to the CPU. Teaching tip Table 5A.3 presents the ASCII code. An exercise that never fails to amuse students is to use the Alt and the number pad to enter letters into an application. As before, open MS Word. Have students hold down the Alt key and type an ASCII value into the number pad. Once they release the Alt, the letter appears. This is a useful skill when the keyboard breaks. Challenge the students to explore numbers above 128.

Mouse It is an input device Moves on a flat surface and controls the pointer Pointer is an on screen object, usually an arrow used to select text, access menus and interacts with file, data program

Mouse Mechanical mouse The most commonly used mechanical mouse has a small rubber ball When the mouse moves The rolling mouse ball spins the roller Information from the roller sent to the system software Software controls the pointer

Mouse Non-mechanical mouse Optical mouse is getting popularity day by day. Light emits from underside It uses the light’s reflection to judge direction, distance and speed

Mouse Benefits of mouse Lets you position the cursor anywhere on the screen quickly without using the keyboard Instead of typing commands through keyboard you can choose commands from menus. Users can draw electronically

Mouse PS/2– Most commonly used; connects to PS/2 port or USB port. Cordless Mouse PS/2 Mouse PS/2– Most commonly used; connects to PS/2 port or USB port. Cordless– Uses infrared signals; must be within sight of the receiving port.

Using the Mouse Mouse buttons enable the user to initiate actions. Clicking (left-, right-, or double-clicking) allows the user to select an item on the screen or open a program or dialog box. Dragging– Holding down the left mouse button and moving the mouse enables the user to move objects on the screen. Double-ckicking- pressing and releasing the mouse button twice in rapid succession Right clicking- pressing and releasing the right button to get some shortcut menu

Mouse button configuration Generally placed at the right side of user Configured for a right-handed user Can be reconfigured Extra buttons are configurable Buttons can be configured for special uses

Variants of the Mouse Trackballs Upside down mouse Hand rests on the ball User moves the ball Uses little desk space

Variants of the Mouse Track pads Stationary pointing device Small plastic rectangle Finger moves across the pad 1.5 to 2 inch in size Popular on laptops

Variants of the Mouse Track point Little joystick on the keyboard Move pointer by moving the joystick Placed between G and H Saves great deal of time and effort Insider information The term track point is copyrighted by IBM.

Ergonomics and Input Devices Study of human and tool interaction Concerned with physical interaction Attempts to improve safety and comfort

Ergonomics and Input Devices Repetitive Stress Injury (RSI) Caused by continuous misuse of the body Many professions suffer from RSI who work for data entry Carpal Tunnel Syndrome Carpal tunnel is a passage in the wrist Holds nerves and tendons Prolonged keyboarding swells tendons Teaching tip Hairstylists often suffer from carpal tunnel. Bicyclists can suffer from overuse injuries of the knee. Page 116 of the text has a diagram of the carpal tunnel.

Carpal Tunnel Syndrome

Ergonomics and Input Devices Office hardware suggestions Office chairs should have Adjustable armrests and height Lower back support Desks should Have a keyboard tray Keep hands at keyboard height Place the monitor at eye level

Ergonomics and Input Devices Techniques to avoid RSI Sit up straight Have a padded wrist support Keep your wrist straight Learn to type Take frequent breaks Use ergonomic keyboard

Ergonomic Keyboard

Chapter 3A End of Chapter