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OLevel

Computer Science 2210

Input Devices

Paper-1

Input Devices

Input Devices:

• Input devices can be described as the peripheral devices that we use to send out signals to the computer system.
• A computer system cannot do the processing without receiving some input from the user.
• Therefore, these devices are used to send raw data for processing to the system.

Types of Input Devices:

• Input devices are of two types:
• Manual Input Device – Devices like keyboard, mouse, and scanner are manual devices that require the user to manually input the data for processing.
• Direct Data Entry Devices (DDE) – Examples include smart cards, optical mark recognition, etc. These devices automatically transfer the data from the source file (e.g. barcode) to the computer system.

Different Input Devices:

• Mouse
• Keyboard
• Concept Keyboard
• 2D & 3D Scanner 
• Trackball
• Graphic Tablets
• Touchscreens
• Microphone
• QR Code Reader
• Digital Camera
• Interactive Whiteboard
• Barcode Reader

1. Mouse:


• It can be wireless or wired and allows the user to control the cursor/pointer’s movement on the screen.
• The user can control the cursor coordinates or movement by moving it over a flat surface.
• The mouse has two to three buttons.
• With the mouse, objects can be clicked/moved, folders can be opened by double-clicking or options of a folder/application can be seen by using the right-click button.
• Today, the mouse has become optical i.e. it uses a laser to track the movement however, in the past mouse used to have a small ball inside them for the tracking.


2. Trackball:


• Besides mouse, a trackball is also an input device i.e. used to control the cursor movement on the screen.
• However, the user keeps the trackball at one position and only moves the ball within it for movement control.
• The trackball is best for users with limited hand motor skills and some people prefer it as it gives great control over the movement without demanding a lot of space to use it.
• Mouse and Trackball are also known as pointing devices.

3. Keyboard:


• It can be wireless or wired.
• It is an input device that allows the user to enter commands or data by pressing keys.
• When a user presses a key, an ASCII code is sent to the computer system.
• A keyboard contains over 100 keys that can be divided into four groups/categories:


- Function keys – contains twelve function keys from F1 – F12 that perform special functions.
- Numeric keys – contains numeric digits 0 – 9, arithmetic signs of plus, multiplication, division, subtraction, and a decimal point.
- Cursor keys – contains arrows for left, right, down and up.
- Main Keyboard – contains the alphabets, special characters, etc.

4. Concept Keyboard:

• A concept keyboard is a keyboard that has keys that are programmed to perform special tasks and have visual images on them instead of letters/characters/numbers.
• For example, a restaurant counter representative may have this keyboard with different meal button, etc.
• Today, these keyboards are replaced by virtual concept keyboards or touchscreens.

5. Microphone: