CS101 Computer Basic
Topic 1: Introduction to Computer System
Topic 2: Central Processing Unit or CPU
Topic 3: Primary Memory or Main Memory
Topic 4: Secondary Memory or Auxiliary Memory
Topic 5: Input and Output Devices
Topic 6: Various Input Devices
Topic 7: Keyboard – Types of Keys
Topic 8: Different types of Pointing Devices
Topic 9: Different types of Scanner
Topic 10: Various Output Devices
Topic 11: Different types of Monitor
Topic 12: Different types of Printers
Topic 13: Other Components and Peripheral Devices
Topic 14: The Operating System – Microsoft Windows
Topic 15: Application Software
Topic 16: Basics of Networking and Internet
Topic 17: Computer Backup and Restore
During the early days, keyboards were the only devices used to input data and instructions into computers. But as time changes, old CUI (Command User Interface) computers were replaced by new GUI (Graphical User Interface) computers. In old computers, instructions were typed by the keyboard. Whereas in new computers, the instructions appear on the screen as icons. These icons are clicked using a pointing device to execute the instructions. To point the icons, there is a pointer on the computer screen which appears like a small arrow. The movement of the pointer can be controlled with a pointing device. Mouse, Track Ball, TouchPad, Pointing Stick, Joystick, and Stylus are the most commonly used pointing devices. So let’s know about some pointing devices –
The mouse is a small pointing device that is similar in size to the real mouse. Like the keyboard, the mouse is also available in both wired and wireless variants. It has generally two buttons called the left and right buttons. The left button is used to select an object or option by pressing it or clicking. While pressing the right button or right-clicking opens a shortcut menu. There is also a wheel between these two buttons, which can be scrolled up and down a page slowly by rotating. The same thing can be done by pressing the wheel.
The mouse is designed to be easily held between the fingers and the palm. By moving it in any direction on a flat surface, the pointer also starts moving in the same direction. The old mouse consisted of a rubber-coated metal ball at the bottom, which rotated through the movement of the mouse on the flat surface. The movement of the pointer was caused by the movement of this ball. Such kinds of mouse are called mechanical mouse. In the new mouse, LED lights and optical sensors are used instead of balls to detect movement. Such a mouse is called an optical mouse.
Apart from these, there are many types of mouse available in the market such as a vertical mouse, air mouse, laser mouse, and even foot mouse.
The trackball is also a pointing device similar to a mouse. It has a ball like the old mechanical mouse. The pointer can be controlled by rolling the ball. But unlike the mechanical mouse, it is fitted on the top side instead of the bottom. Due to the ball being placed upside, it is very convenient to use without moving the hand. Trackballs also have buttons for left and right-click.
Touchpad or Trackpad
The touchpad or trackpad is also a pointing device. It is used instead of the mouse in portable computers like laptops. It is a rectangular plate that resides in the middle of the palm rest under the keyboard. The pointer can be controlled by moving the fingers on its flat surface. It also has two buttons that function like mouse buttons.
Some laptops have a small vertical stick with a rubber cap between The G, H, and B buttons of the keyboard. This stick is called the pointing stick and its cap is called the nub. The pointing stick is a mouse alternative just like a touchpad. It can also be called a miniature version of the joystick which can be pressed in any direction with a finger. Pressing in this way can control the movement of the pointer. Along with the pointing stick, two or three extra buttons are also placed under the keyboard. These buttons can be left and right clicked just like a mouse. Its biggest advantage compared to the mouse and touchpad is that it can be used without moving the hand from the keyboard.
In earlier times, a pointing stick was placed under the J button which was called the J mouse.
The joystick is mostly used in playing video games. Apart from this, it is also used in plane simulators, unmanned vehicles, CCTV, etc. It has two parts, a vertical handle, and a base. One end of the handle is pivot in the base and its other end is kept free. By holding the handle and tilting it in any direction, the pointer or object also starts moving in the same direction. There are also some buttons on its handle and base which can be programmed for different tasks.
The stylus is a pen-shaped pointing device. It can be used as a pen on a touch screen or a graphic tablet. Mostly it is used for drawing, writing, and marking on the computer. These are of two types – passive stylus and active stylus. The passive stylus has no electronic circuit. They work with conductive rubber tip or pressure, just like we can work on a touch screen with our fingers. While the active stylus has an electronic circuit that tells the position of the stylus tip above the tablet or screen. It also monitors the pressure applied at the tip, so that the thickness of the lines drawn can also be controlled.
Lightpen is an older version of a stylus. It is a light-sensitive input device that could only be used with older CRT monitors. Lightpens are used in drawing lines, selecting and modifying the text on the screen, etc. They are obsolete nowadays.
Apart from all these pointing devices, the keyboard can also be used as a pointing device. For this, there is an option of mouse keys in the setting. This option allows the keyboard’s numeric keypad to control the movement of the pointer.