Input/outputIn computing, input/output or 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. I/O devices are used by a person (or other system) to communicate with a computer. For instance, a keyboard or a mouse may be an input device for a computer, while monitors and printers are considered output devices for a computer. Devices for communication between computers, such as modems and network cards, typically serve for both input and output.

Note that the designation of a device as either input or output depends on the perspective. Mouse and keyboards take as input physical movement that the human user outputs and convert it into signals that a computer can understand. The output from these devices is input for the computer. Similarly, printers and monitors take as input signals that a computer outputs. They then convert these signals into representations that human users can see or read. For a human user the process of reading or seeing these representations is receiving input. These interactions between computers and humans is studied in a field called human–computer interaction.

In computer architecture, the combination of the CPU and main memory (i.e. memory that the CPU can read and write to directly, with individual instructions) is considered the brain of a computer, and from that point of view any transfer of information from or to that combination, for example to or from a disk drive, is considered I/O. The CPU and its supporting circuitry may provide memory-mapped I/O that is used in low-level computer programming, such as the implementation of device drivers, or may provide access to I/O channels. An I/O algorithm is one designed to exploit locality and perform efficiently when data reside on secondary storage, such as a disk drive.

Input Devices:

KeyboardsA 'keyboard' is a human interface device which is represented as a layout of buttons. Each button, or key, can be used to either input a linguistic character to a computer, or to call upon a particular function of the computer. Traditional keyboards use spring-based buttons, though newer variations employ virtual keys, or even projected keyboards.

Pointing devicesKeyboard devices are the most commonly used input devices today. A pointing device is any human interface device that allows a user to input spatial data to a computer. In the case of mice and touchpads, this is usually achieved by detecting movement across a physical surface. Analog devices, such as 3D mice, joysticks, or pointing sticks, function by reporting their angle of deflection. Movements of the pointing device are echoed on the screen by movements of the pointer, creating a simple, intuitive way to navigate a computer's GUI.

High-degree of freedom input devicesSome devices allow many continuous degrees of freedom as input. These can be used as pointing devices, but are generally used in ways that don't involve pointing to a location in space, such as the control of a camera angle while in 3D applications. These kinds of devices are typically used in CAVEs, where input that registers 6DOF is required.

Composite devicesInput devices, such as buttons and joysticks, can be combined on a single physical device that could be thought of as a composite device. Many gaming devices have controllers like this. Technically mice are composite devices, as they both track movement and provide buttons for clicking, but composite devices are generally considered to have more than two different forms of input.

Game controller Gamepad (or joypad) Paddle (game controller) Jog dial/shuttle (or knob) Wii Remote

Imaging and input devices

Video input devices are used to digitize images or video from the outside world into the computer. The information can be stored in a multitude of formats depending on the user's requirement.

Digital camera Digital camcorder Portable media player Webcam Microsoft Kinect Sensor Image scanner Fingerprint scanner Barcode reader 3D scanner Laser rangefinder Eye gaze tracker

Medical Imaging

Computed tomography Magnetic resonance imaging Positron emission tomography Medical ultrasonography

Audio input devices

In the fashion of video devices, audio devices are used to either capture or create sound. In some cases, an audio output device can be used as an input device, in order to capture produced sound.

Microphones MIDI keyboard or other digital musical instrument

Storage input devices

In this device data can be stored.

Basic computer componentsInput

devices Keyboard Image scanner Microphone Pointing device

o Graphics tablet o Joystick o Light pen o Mouse

o Pointing stick o Touchpad o Touchscreen o Trackball

Webcam o Softcam

Refreshable braille display

Output devices

Monitor Refreshable braille display Printer Speakers

Plotter

Removabledata

storage

Optical disc drive o CD-RW o DVD+RW

Disk pack Floppy disk Memory card

USB flash drive

Computer case

Central processing unit (CPU) HDD / SSD / SSHD Motherboard Network interface controller Power supply Random-access memory (RAM) Sound card

Video card

Data ports

Ethernet FireWire (IEEE 1394) Parallel port Serial port USB

audio jack

Types of output

Some types of output are text, graphics, tactile,[4] audio, and video. Text consists of characters (letters, numbers, punctuation marks, or any other symbol requiring one byte of computer storage space) that are used to create words, sentences, and paragraphs. Graphics are digital representations of nontext information such as drawings, charts, photographs, and animation (a series of still images in rapid sequence that gives the illusion of motion). Tactile output such as raised line drawings may be useful for some

individuals who are blind. Audio is music, speech, or any other sound. Video consists of images played back at speeds to provide the appearance of full motion.[3]

Display devices

A display device is an output device that visually conveys text, graphics, and video information. Information shown on a display device is called soft copy because the information exists electronically and is displayed for a temporary period of time. Display devices include CRT monitors, LCD monitors and displays, gas plasma monitors, and televisions

Audio

An audio signal is a representation of sound, typically as an electrical voltage. Audio signals have frequencies in the audio frequency range of roughly 20 to 20,000 Hz (the limits of human hearing). Audio signals may be synthesized directly, or may originate at a transducer such as a microphone, musical instrument pickup, phonograph cartridge, or tape head. Loudspeakers or headphones convert an electrical audio signal into sound. Digital representations of audio signals exist in a variety of formats.[1]

Printer (computing)In computing, a printer is a peripheral which makes a representation of an electronic document on physical media. Individual printers are designed to support local and network users at the same time. Some printers can print documents stored on memory cards or from digital cameras and scanners.

Consumer and some commercial printers are designed for low-volume, short-turnaround print jobs; requiring virtually no setup time to achieve a hard copy of a given document. However, printers are generally slow devices (30 pages per minute is considered fast, and many inexpensive consumer printers are far slower than that), and the cost per page is actually relatively high. However, this is offset by the on-demand convenience and project management costs being more controllable compared to an out-sourced solution. The printing press remains the machine of choice for high-volume, professional publishing. However, as printers have improved in quality and performance, many jobs which used to be done on printing presses are now done by print on demand or by users on local printers; see desktop publishing. Local printers are also increasingly taking over the process of photofinishing as digital photo printers become commonplace.

The world's first computer printer was a 19th-century mechanically driven apparatus invented by Charles Babbage for his difference engine.[1]

A virtual printer is a piece of computer software whose user interface and API resembles that of a printer driver, but which is not connected with a physical computer printer.

Speech-generating deviceSpeech-generating devices (SGDs), also known as voice output communication aids, are electronic augmentative and alternative communication (AAC) systems used to supplement or replace speech or writing for individuals with severe speech impairments, enabling them to verbally communicate their needs.[1] SGDs are important for people who have limited means of interacting verbally, as they allow individuals to become active participants in communication interactions.[2]

Stephen Hawking, physicist and SGD user

ProjectorA projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen.

Most projectors create an image by shining a light through a small transparent lens, but some newer types of projectors can project the image directly, by using lasers. A virtual retinal display, or retinal projector, is a projector that projects an image directly on the retina instead of using an external projection screen.

Graphics

Graphical output displayed on a screen.

A digital image is a numeric representation of an image stored on a computer. They don't have any physical size until they are displayed on a screen or printed on paper. Until that point, they are just a collection of numbers on the computer's hard drive that describe the individual elements of a picture and how they are arranged.[5] Some computers come with built-in graphics capability. Others need a device, called a graphics card or graphics adapter board, that has to be added.[6] Unless a computer has graphics capability built into the motherboard, that translation takes place on the graphics card.[7] Depending on whether the image resolution is fixed, it may be of vector or raster type. Without qualifications, the term "digital image" usually refers to raster images also called bitmap images. Raster images that are composed of pixels and is suited for photo-realistic images. Vector images which are composed of lines and co-ordinates rather than dots and is more suited to line art, graphs or fonts.[5] To make a 3-D image, the graphics card first creates a wire frame out of straight lines. Then, it rasterizes the image (fills in the remaining pixels). It also adds lighting, texture and color.[7]

Video card

NavaratnasNavaratnas Nauratan (Sanskrit dvigu nava-ratna- or "nine gems") was a term applied to a group of nine extraordinary people in an emperor's court in India. Some well-

known groups are in the Raaj Sabha (court) of King Janaka, Emperor Vikramaditya and in Emperor Akbar's "darbar".

The Mughal ruler Akbar, despite his illiteracy, was a great lover of the artists and intellectuals. His passion for knowledge and interest in learning from great minds led him to attract men of genius to his court, known as the nine courtiers of Emperor Akbar or Navratnas:[1]

Abu'l-Fazl ibn MubarakShaikh Abu al-Fazal ibn Mubarak (Persian: الفضل ,also known as Abu'l-Fazl (ابوAbu'l Fadl and Abu'l-Fadl 'Allami (1551 – August 12, 1602) was the vizier of the great Mughal emperor Akbar, and author of the Akbarnama, the official history of Akbar's reign in three volumes, (the third volume is known as the Ain-i-Akbari) and a Persian translation of the Bible.[1] He was also one of the Nine Jewels (Hindi: Navaratnas) of Akbar’s royal court and the brother of Faizi, the poet laureate of emperor Akbar.

Abu'l-Fazl presenting Akbarnama to Akbar, Mughal miniature

Abdul Rahim Khan-I-KhanaKhanzada Mirza Khan Abdul Rahim Khan-e-Khana (17 December 1556 – 1626) (Hindi: अब्दुल रहीम ख़ान-ए-ख़ाना, Urdu: خانخان also known as Rahim ,(عبدالرحيم(रहीम, رحیم) was a poet who lived during the rule of Mughal emperor Akbar. He was one of the nine important ministers (dewan) in his court, also known as the Navaratnas. Rahim is known for his Hindi couplets and his books on astrology.[1] The village of Khankhana, which is named after him, is located in the Nawanshahr district of the state of Punjab, India.

Apart from writing various dohas, Rahim translated Babar's memoirs, Baburnama from Chagatai language to Persian language, which was completed in AH 998 (1589–90). His command of Sanskrit was very good.[9] He wrote two books on astrology, Kheta Kautukama and Dwawishd Yogavali.

Young Abdul Rahim Khan-I-Khana being received by Akbar

Birbal

Birbal (IPA: [bi ː rbəl] ; born Mahesh Das; 1528–1586) or more accurately Rajah Birbar, was a Hindu advisor in the court of the Mughal emperor Akbar during his rule in India and is mostly remembered in folk tales, which focus on his wit. He belonged to the Brahmin class and was appointed by the Emperor as a poet and singer around 1556–1562, later formed a close association with him, becoming an important advisor and soon being sent on military expeditions despite having no previous background. In 1586, the Emperor sent an army led by Birbal to crush an unrest in the north-west Indian subcontinent, which failed tragically when he was killed along with many troops in an ambush by the rebel tribe. This was one of biggest military setbacks during his reign and Birbal's death is said to have caused much grief to the Emperor.

Near the end of Akbar's reign, local folk tales began to emerge involving his interactions with Birbal, in which he was portrayed as being extremely clever and witty. As the tales gained popularity in India, he became even more of a legendary figure. He was mostly shown as being younger than Akbar, religious and being surrounded by envious Muslim courtiers; these tales involve him outsmarting them and sometimes even the Emperor, using only his intelligence and cunning, often with giving witty and humorous responses and impressing the Emperor. Some stories are told in versions containing a different set of characters from other Indian folklore. By the twentieth century onwards, plays, films and books based on these folk tales were made, some of these are in children's comics and textbooks.

FaiziShaikh Abu al-Faiz ibn Mubarak, popularly known by his pen-name, Faizi (24 September 1547 – 5 October 1595 [1]) was a poet and scholar of late medieval India. In 1588, he became the Malik-ush-Shu'ara (poet laureate) of Akbar's Court.[2] He was the

elder brother of Akbar's historian Abul Fazl. Akbar highly recognized the genius in him and appointed him tutor for his sons and gave place to him among his decorative 'Navaratnas'.

He composed significant poetic works in Persian and is ascribed by Bada'uni and his other contemporaries to have composed over a hundred poetic works, but all the titles are not known to us. His Divan (collection of poems), was entitled Tabashir al-Subh. His Divan comprises qasidas, ghazals, ruba'is and elegies.[3] The exaltation of pantheism in some of his lyrics brought on him the enmity of the orthodox Muslim clergy.[4][5]

In pursuance of the literary practice then in vogue, Faizi planned to produce a Panj Ganj (literally five treasures) or Khamsa in imitation of the Persian poet Nizami Ganjavi. At the age of 30, he started writing five works: the Nal o Daman (a Persian imitation of the famous Indian epic Nala and Damayanti), the Markaz ul-Advar (The Centre of the Circle), the Sulaiman o Bilqis (Solomon and Balkis — the queen of Sheba), the Haft Kishvar (The Seven Zones of the Earth) and the Akbarnama (The History of Akbar). His two completed works, the Markaz ul-Advar and the Nal o Daman (completed in 1594) was the javab (imitation) of Nizami's the Makhzan ul-Asrarand the Layla o Majnun.[3] His other three incomplete works, the Sulaiman o Bilqis, the Haft Kishvar and the Akbarnama were the imitations of the Khusraw o Shirin, the Haft Paykar and the Sikandarnama respectively.[2][5]

During his stay in Deccan from 1591-3, Faizi wrote a celebrated series of reports on political and cultural conditions of Deccan, as well as contemporary Iran.[1] He wrote a commentary on the Quran, and translated Bhaskaracharya's celebrated Sanskrit work on mathematics, Lilavati, into Persian. According to its preface, this work was completed in AH 995 (1587).[6] Friedrich Max Müller's Introduction to the Science of Religion (1870, last ed. 1882) has a number of metrical paraphrases of Faizi's poems.[7]

Man Singh I

Man Singh (Man Singh I) (December 21, 1550 – July 6, 1614) was the Kacchwaha King of Amber, a state later known as Jaipur. He was a trusted general of the Mughal emperor Akbar, who included him among the Navaratnas, or the 9(nava) gems(ratna) of the royal court.[1][2]

Todar Mal

Raja Todar Mal was born in Laharpur, Uttar Pradesh [1] [2] in a Hindu Kayastha family,[3]

[4][5] and rose to become the Finance Minister in Akbar's Darbar of the Mughal empire.

Tansen

Mian Tansen (born 1493 or 1506 as Ramtanu Pandey – died 1586 or 1589 as Tansen) was a prominent Hindustani classical music composer, musician and vocalist, known for a large number of compositions, and also an instrumentalist who popularized and improved the plucked rabab (of Central Asian origin). He was among the Navaratnas

(nine jewels) at the court of the Mughal Emperor Jalal ud-din Akbar. Akbar gave him the title Mian, an honorific, meaning learned man.[1]

Musical legacy

The legendary musical prowess of Tansen surpasses all other legends in Indian music. In terms of influence, he can be compared to the prolific Sufi composer Amir Khusro (1253–1325), or to Bhakti tradition composers such as Swami Haridas.

Several of his raga compositions have become mainstays of the Hindustani tradition, and these are often prefaced with Mian ki ("of the Mian"), e.g. Mian ki Todi, Mian ki Malhar, Mian ki Mand, Mian ka Sarang; in addition he is the creator of major ragas like Darbari Kanada, Darbari Todi, and Rageshwari.

Tansen also authored Sangeeta Sara and Rajmala which constitute important documents on music.

Almost every gharana (school) tries to trace its origin to him, though some try to go further back to Ameer Khusro. The Dagar family of dhrupad singers believe themselves to be the direct descendants of not Tansen but his guru, Haridas Swami. As for the Dhrupad style of singing, this was formalized essentially through the practice by composers like Tansen and Haridas, as well as others like Baiju Bawra who may have been a contemporary.

After Tansen, some of the ideas from the rabab were fused with the traditional Indian stringed instrument, veena; one of the results of this fusion is the instrument sarod, which does not have frets and is popular today because of its perceived closeness to the vocal style.

The famous qawwals, the Sabri Brothers claim lineage from Mian Tansen[33] This information of Sabri brothers being the descendant of Mian Tansen is completely wrong. This has been confirmed by Imtiaz Ali Khan,the last descendant of Mian Tansen.[34]

A national music festival known as 'Tansen Sangeet Sammelon' is held every year in December, near the tomb of Tansen at Behat as a mark of respect to his memory.

Shaikh Mubarak

Shaikh Mubarak A sufi, Shaikh Mubarak was the brain behind Akbar's MahZAT or declaration which has been wrongly called a 'Decree of Infallibility'.

Hamim Humam

Hamim Humam A very close friend of Akbar, Hamim Humam was the chief of royal school (pathasiila).

(i) Birbal A brahman of Kalpi, Birbal is known for his gift of humour and wits. His original name was Mahesh Dass. He was in charge of administration of justice at the

royal court. He died fighting with the Yousuf-zai tribe on the north-west frontier of India.(ii) Todar Mal He is known for his expertise in land revenue matters. Starting his career under Sher Shah, he evolved a land revenue system which was followed not only by Sher Shah and Akbar but also by the Marathas.(iii) Tansen Born at Gwalior, Tansen was a court singer ofAkbar. He is known as Geet SamTat.(iv) Abul Fazal A profound thinker and writer, Abul Fazal is known for his books, Akbarnama and Ain-i-Akbari. Prince Salim's instigation led to his murder.(v) Abdul Rahim Conferred the title of Khan-e-Khana by Akbar, Abdul Rahim was a celebrated Hindi scholar. He is remembered for Rahim Satsai (a collection of dohas). He was also a great scholar of Tufki (he translated 13aburnama into Turki) and Persian languages.(vi) Raja Man Singh A greatRajput~eneral of Akbar, ManSingh is credited with defeating Maharana Pratap, in the battle of Haldighati, and the Afghans.(vii) Faizi A poet laureate of Akbar's court, Faizi is creditedwith the translation of Leelawati into Persian.