Tutorial 1- Keyboard and Screen Input DevicesCE406 – Computer Peripherals Workshop16BCE059Qasim Burhan BhatiaAbstractThis report briefly summarises the presentation given by 16BCE060 and 16BCE063 on Keyboard and Screen Input Devices and a few other topics they may have left out.IntroductionThe keyboard is an essential input device and has been around for since the first terminal based computers were made in the 1930s. With the advent of touch screens, keyboards are present even as screen input devices. In this report we discussThe function of a keyboard and its workingDifferent categories of keyboardsBased on layoutBased on connection typeBased on key mechanismNew types of keyboardsErgonomic keyboardVirtual keyboardOnscreen keyboardFunction of a KeyboardA keyboard is an input device which takes character inputs from the user and feeds it to the system for processing. It is a crucial peripheral device which is needed in all modern computers today. These keys on a keyboard represent two or more characters which are chosen using different modifier key like – SHIFT,ALT,CTRL. These keystrokes are encoded in machine readable form and given to a computer input register for further processing. The following diagram from the presentation briefly explains the working of an generic keyboard.The keyboard’s driver software is the medium which connects the keyboard to the computer, it reads the input strokes and transfers them to the OS and hence acts as a interface between a keyboard and the CPU. All keyboard automatically install its driver software when first connected.Categories of KeyboardsBased on Key ArrangementModern keyboards use multiple layout for keys based on the region of the keyboard, the most prominent keyboard layouts are named :QWERTYAZERTY QWERTZHCESARDVORAKDVORAK is special among them as it is not named after the first six keys in the top row, it is named after its designer Dr August Dvorak. Dvorak proponents claim the layout requires less finger motion and reduces errors compared to the standard QWERTY keyboard arrangement. It is claimed that the reduction in finger distance traveled permits faster typing while also reducing repetitive strain injuries, although that claim is controversial.Based on Connection TypeThere are three types of connections a keyboard can have: USBPS/2WirelessThe USB(Universal Serial Bus) connector is normally preferred when considering wired keyboards, whereas the PS/2 is still used, but is regarded as a legacy port. Wireless keyboard uses bluetooth or the 2.4GHz band to communicate with the computer via a miniature USB dongle.Based on Key MechanismThe key switch mechanism determines the tactile response of the keys when pressed. The most common mechanisms are:Mechanical KeyboardMembrane KeyboardRubber Dome KeyboardCapacitive KeyboardMechanical Keyboards have full mechanical switch for each key, they are more durable than its counterparts.Membrane Keyboards don’t have individual keys, but instead are on continuous layers on which have symbols printed on them. Pressure pads connect two separate layers to complete a circuit to register a keystroke.Rubber Dome Keyboards have a collapsible rubber dome as each key, they are tactile and small and used in many keyboards.Capacitive Keyboards uses changes in capacitance, or stored static electricity, rather than changes in flows of electricity used by contact keyboards to register when a user has depressed a specific key on the keyboard.New Keyboard TypesErgonomic KeyboardRegular keyboards cause strain on our wrists and arms as we type for extended periods of time. Ergonomic keyboard attempt to solve this problem by added cushion pads, new keyboard layouts and entirely new configurations. Following are some pictures of such keyboards:Virtual KeyboardVirtual keyboard project a keyboard layout onto surface where a user can type. Various sensors try to judge which key is being pressed by determining our finger’s relative position with respect to the projection of the keyboard.On Screen KeyboardA keyboard is displayed on a touchscreen interface, where users touch keys to input characters. These keyboards can be changed to many languages supported by the OS and may also include special features like emojis and handwriting input.