Input Output Devices Of Computer Pdf Download ((FREE))

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In computing, input/output (I/O, i/o, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Inputs are the signals or data received by the system and outputs are the signals or data sent from it. The term can also be used as part of an action; to "perform I/O" is to perform an input or output operation.

.mw-parser-output .vanchor>:target~.vanchor-text{background-color:#b1d2ff}I/O devices are the pieces of hardware used by a human (or other system) to communicate with a computer. For instance, a keyboard or computer mouse is an input device for a computer, while monitors and printers are output devices. Devices for communication between computers, such as modems and network cards, typically perform both input and output operations. Any interaction with the system by a interactor is an input and the reaction the system responds is called the output.

An I/O interface is required whenever the I/O device is driven by a processor. Typically a CPU communicates with devices via a bus. The interface must have the necessary logic to interpret the device address generated by the processor. Handshaking should be implemented by the interface using appropriate commands (like BUSY, READY, and WAIT), and the processor can communicate with an I/O device through the interface. If different data formats are being exchanged, the interface must be able to convert serial data to parallel form and vice versa. Because it would be a waste for a processor to be idle while it waits for data from an input device there must be provision for generating interrupts[2] and the corresponding type numbers for further processing by the processor if required.[clarification needed]

A computer that uses memory-mapped I/O accesses hardware by reading and writing to specific memory locations, using the same assembly language instructions that computer would normally use to access memory. An alternative method is via instruction-based I/O which requires that a CPU have specialized instructions for I/O.[1] Both input and output devices have a data processing rate that can vary greatly.[2] With some devices able to exchange data at very high speeds direct access to memory (DMA) without the continuous aid of a CPU is required.[2]

Higher-level operating system and programming facilities employ separate, more abstract I/O concepts and primitives. For example, most operating systems provide application programs with the concept of files. The C and C++ programming languages, and operating systems in the Unix family, traditionally abstract files and devices as streams, which can be read or written, or sometimes both. The C standard library provides functions for manipulating streams for input and output.

In the context of the ALGOL 68 programming language, the input and output facilities are collectively referred to as transput. The ALGOL 68 transput library recognizes the following standard files/devices: stand in, stand out, stand errors and stand back.

This part of the computer encapsulates devices with the help of which the user feeds data to the computer. It creates an interface between the user and the computer. The input devices transform the information into a form acceptable by the computer.

This part of the computer encapsulates devices with the help of which the user receives the information from the computer. Output devices transform the output from the computer into a form understandable by the users.

The keyboard is the most basic and very commonly used input device which helps to input data to the computer. The layout of the buttons in a normally used keyboard is similar to the traditional typewriter, but there are a few additional keys provided by different manufacturers for performing additional functions.

The trackball is another type of input device similar to the mouse. It is most helpful with a notebook or laptop computer, instead of a mouse. It consists of a ball on the top which is half inserted and connected to the sensors. By moving fingers on the ball, the cursor can be moved.

A scanner is another input device, which works very much like a photocopy machine. It can be used when some information on paper is to be transferred to the hard disk of the computer in digital format for further manipulation.

A digitizer is also an input device that is used to convert analog information into digital form. Using a digitizer, the signal from the television or camera can be transformed into a series of numbers that could be saved in a computer hard drive. They can be helpful with the computer to create a picture of whatever the camera has been pointed at.

A microphone or mic is a very common input device used to input sound that is then stored in a digital form. Nowadays microphones are used in almost every industry and devices related to sound recording or transmission.

A flash of light from the device strikes the surface of the object and reflects the sensors present behind the source of light to collect the input. Bar Code Reader can only scan a bar code image, converts it into an alphanumeric value, which is then transferred to the computer that the bar code reader is connected to.

A Webcam is a camera that is combined with a computer. Unlike a digital camera, they cannot function independently and should be connected to the computer/laptop for operation. It functions as an input device that can take pictures and is mostly used for video streaming and video conferencing or chatting.

A piece of hardware/equipment that presents the result of the entered input, once it is processed, is called an output device. Several output devices display output in various ways such as images, text, hard copies, and audio/video. Following are some of the commonly used output devices used in a computer system:

Monitors or Visual Display Unit (VDU), are the primary output devices of a computer system. It generates images from tiny dots, termed pixels that are arranged in a well-defined rectangular form. The depth and sharpness of the image depend upon the number and size of the pixels.

The flat-panel display is a class of video output devices that have decreased volume, weight, and power requirement as compared to the CRT. It is possible to hang them on walls or wear them on wrists. In everyday evolving technology, uses of flat-panel displays include laptops or computers, calculators, monitors, video games, and graphics displays.

A projector is an optical output device that can take images produced by a computer and project or present them onto a screen or surface called a projector. In the older version of projectors, images were created by shining the light through a small transparent lens on the projector; however, the new version of projectors uses laser technology for the same. Projectors are most commonly used in offices, classrooms, auditoriums, theatres to watch presentations, videos, or pictures generated from a computer or laptop.

Computer speakers are the most popular output devices used with a computer to listen to sound. These speakers receive audio as input either in analog or digital form and generate sound as an output. With the advancement of technology, speakers are now available with wireless and BlueTooth facilities as well.

The headphones or earphones or headsets are hardware output tools that are either plugged into the computer or can be wireless. They offer the same function as a speaker, the only difference is the frequency of sound. With speakers, the sound can be detected over a larger distance while utilizing headphones, the sound is only audible to the individual using them. Headphones are available in multiple shapes and sizes.

An I/O device error (short for Input/Output device error) happens when Windows is not able to perform an input/output action (such as reading or copying data) when it is trying to access a drive or disk. 2b1af7f3a8

Input Output Devices Of Computer Pdf Download ((FREE))

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