Speakers Speakers are one of the most common output devices used on computers to achieve audio output. Computer speakers usually receive signals from the sound card and then convert them to audio. These speakers use internal amplifiers that vibrate at different frequencies to increase/decrease the volume or amplitude of the sound as per the choice of the user. Most monitors and laptops come with inbuilt speakers. However, we can also connect external speakers to the computer via both wired and wirelessly. The speakers are mainly used to obtain the loud sound output. 46
Headphones Headphones, also known as earphones, are output devices that allow us to listen to audio from a computer. These devices are mainly used to listen to audio privately or without disturbing others around. Headphones come in a variety of sizes and designs and can connect with supported devices via both wired or wirelessly. Headphones primarily receive audio input from connected devices and convert them into audio output in waveforms. Many headphones come with a microphone, making them a great device for communicating with family or friends. These output devices are mostly used to communicate in gaming and on bulk calls. 47
Sound Card A sound card, also known as an expansion card, is a type of output device that is usually installed on a motherboard in the inner case of a computer. The main function of a sound card is to control the output of sound signals and enable devices such as speakers and headphones to function. Sound cards usually work with the help of drivers and software. Although a sound card is not mandatory for the basic functions of a computer system, it is added to the computer for listening to audio, playing games, watching movies, listening to music, video conferencing, and more. 48
Video Card As the sound card, a video card is also an expansion card installed on the slots in the motherboard. The primary function of a video card is to process images and videos so that their visuals are displayed on the screen. It is also known as a video adapter. A video card is a basic requirement of a computer system and therefore most computers come with regular video and graphics capabilities to display images and video. However, to get more detailed graphics, a higher video card is required. This is why most gaming computers and laptops use additional (dedicated) video cards. 49
GPS (Global Positioning System) GPS or a global positioning system is a radio-based navigation system consisting of a network of multiple satellites. It uses a system of about 31 satellites located in space to provide accurate results. The satellites use microwave signals to interact with GPS devices. Nowadays GPS is mostly found in smartphones, smartwatches, laptops, etc. Anyone can use this system to get the location on the map. This mainly helps in obtaining the exact location of connected devices or locations on the map in the form of latitude and longitude coordinates on the Earth. In addition, these devices provide information on vehicle speed, weather conditions, and many other pieces of data. 50
Speech-Generating Device (SGD) Speech generating devices are output devices that help generate voice output from the text displayed on a computer screen. In particular, these devices convert text to speech. Additionally, whenever a user enters something from the keyboard and when the command is executed, SGD can help listen to the entered data as sound output. Speech generating devices are also known as speech synthesizers and voice output communication aids. These output devices are widely used in telephone exchanges and the treatment of blind and mute people. 51
Plotter A plotter is an output device that is almost identical to a printer. However, it is primarily used to print vector graphics with high quality. Unlike a printer, a plotter has various advanced features and can also print on cardboard, film, fabric, and many other synthetic surfaces. The plotter helps to produce large-size hardcopies of graphics or designs. It derives the design from the graphic card and then interprets the vector graphics. A plotter usually uses color pens to draw multiple lines between different points to create the entire design. Plotters are expensive compared to printers. 52
Summary This topic covers more than 10 examples of output devices used for computers, including their names, pictures, and functions on each. The primary function of an output device is to retrieve data from a computer and convert it into a human-readable form because we cannot understand data in machine language. 53
a) Define output and output device b) What is a Display device? c) How to measure the quality of a monitor? Explain briefly. d) Define Impact printer and Non Impact printer. REVIEW QUESTIONS 54
Output is data that has been processed into a useful form such as printers and projectors. A display visually conveys text, graphics, and video information The quality of a display depends primarily on its resolution response time, brightness, dot pitch and contrast radio. Impact printers form characters and graphics on a piece of paper by striking a mechanism against an inked ribbon that physically contacts the paper and a nonimpact printer forms characters and graphics on a piece of paper without actually contacting the paper. a) Define output and output device b) What is a Display device? c) How to measure the quality of a monitor? Explain briefly. d) Define Impact printer and Non Impact printer. REVIEW ANSWERS 55
DIFFERENCE BETWEEN INPUT AND OUTPUT “Computers are incredibly fast, accurate, and stupid. Human beings are incredibly slow, inaccurate, and brilliant. Together they are powerful beyond imagination.” - Albert Einstein C H A P T E R 4 DEVICES 56
An input device is a hardware component connected to a computer that accepts data/instructions by the user and turns it into a pattern of electrical signals in binary code understandable to the computer. An input device cannot receive data from another device. However, it can transmit data to another device. An input device is a user-controlled device with complex coding. What is an Input Devices A computer system is a combination of several hardware devices or components. When all the components are connected and the appropriate software is installed, it combined forms a computer. However, to interact with computer systems, we generally use input and output devices. Both of these have an important role in the functionality of a computer system and there are significant differences between input and output devices Before we compare input and output devices of a computer, let us first understand both with their brief definitions. INPUT OUTPUT DEVICE The computer can be programmed with some predefined code to operate itself; but, we will not be able to feed the data in real-time. With input devices, users can feed data in real-time to perform more advanced operations. 57
An output device is a hardware component connected to a computer that converts the computer's received digital signal into a form understandable to users. Technically, it provides the result of processing or processed data. An output device is a computer controllable device and is known to receive data from other devices to generate output. What is an Output Devices The computer can work without an output device; however, we will not be able to display the results to be sure whether the processing of the data is going in the right direction. Output devices are technically the opposite of input devices. An input device is a hardware device that is used to deliver data to a computer for processing, whereas an output device is a hardware device that is used to receive data from a computer to obtain results for the users. The user can control the input devices accordingly. In contrast, the output devices are controlled by the computer’s processor itself. Input devices have a complex design as compared to output devices. Input devices mainly convert user-friendly instructions into machinefriendly language. On the other hand, output devices mainly convert the instruction of the machine into a user-friendly form. The most common input devices include a mouse, keyboard, microphone, and webcam. In contrast, the most common output devices include a monitor, printer, and speakers. Let us list down some of the major differences between input and output devices: Input Devices Vs Output Devices 58
Input Device Output Device An input device is connected to the computer to feed data from the user to the computer. An output device is connected to a computer to provide data from the computer to the user. The input device is controlled by the user. The output device is controlled by the computer (specifically the CPU). Input devices translate user-friendly inputs into machineunderstandable inputs. Output devices translate machinefriendly outputs into userunderstandable outputs. An input device helps to enter data or instructions to be processed by the computer. An output device generates results from the processed data to provide the desired result to the user. The design or coding of input devices is more complex. This is because an input device ensures that the user can interact with the computer properly. The design or coding of output devices is less complex. This is because output devices only display results and do not require them to learn the procedures. An input device is necessary for the computer to receive user commands or to receive data to be processed by the processor. An output device is necessary for a computer to share its results and to prompt users for more information or commands. An input device can generally transmit data to other devices. However, it usually does not accept data from other devices. An output device can accept data from other devices and further process the data accordingly. However, it usually does not transmit data to other devices. Difference Between Input and Output Devices Let’s discuss the differences between Input and Output devices side by side with the help of the following comparison table: 59
This topic differentiates the input device from the output device. Generally, both the input and output devices are opposite to each other. An input device sends the information received by the users to the computer system for processing. On the other hand, an output device reproduces or displays the results of processing by the computer system to the users. Summary The above image displays some input devices, some output devices, and some input-output devices. 60
a) Mike Meyers' CompTIA A+ Certification Passport, Sixth Edition b) CompTIA® IT FundamentalsTM (Exam FCo-U51) c) https://www.geeksforgeeks.org/input-and-output-devices/ d) https://byjus.com/govt-exams/input-output-devices/ e) https://en.wikipedia.org/wiki/Input/output f) http://www.ignou.ac.in/upload/UNIT%204-BSC-011-BL1.pdf REFERENCES 61