Keyboards are an indispensable accessory for a computer. One of the most basic input devices, computer keyboards are used in navigation, execution of processes, programming and several other purposes. Several software based application directly derive their existence from a keyboard. For instance, social networking websites, programming languages, navigation over the computer menus etc. utilize a computer keyboard. Even this very article wouldn’t have been possible without a keyboard.
A normal computer keyboard is composed of around 110 keys. Although on the basis of key arrangements there are four major keyboard layouts being used worldwide, QWERTY, AZERTY, QWERTZ and HCESAR, but they can be classified in many more different categories depending on types of computer connector, size, number of keys etc. Among the various types listed below, keyboards can be based on multiple types. For instance, an ergonomic keyboard can have a PS2 interface and be an internet keyboard too.
The artifact of this keyboard is slightly broader and different in shape, when compared with the normal keyboard. In this key board certain space will be existing between the two sets of keys and the countered shape of this key board allow the users to place their hands in the natural position to type. These key boards are mostly used by the people who often work with the key board as their usage is easier and is less stressful for the wrist. The following figure: Ergonomic keyboard shows how the set of keys are separated with gaps in between.
ADB (Apple Desktop Bus)
ADB refers to a special type of port which is enabled in some computers such as Apple computers. The ADB key boards can be connected only to the ADB jack enabled computers, but with the use of the adapter, the ADB key boards can also be inserted over a USB port.
An obsolete type, these keyboards only support the older computers such as IBM 8086/8088, XT-286. Not supported by present computers, keyboards are much larger than the modern keyboards and the “Enter” key is backward-”L” shaped.
PERSONAL SYSTEMS (PS/2)
In the late 1990, most of the computers are integrated with standard PS/2 connector, rather than USB ports, there by the keyboards used for these computers are usually round pin that fits into the PS/2 keyboard jack. For this reason these keyboards are named as PS/2 keyboards.
The MINI PS/2 keyboards are very small in size and are compatible with the PS/2 computers. This keyboard resembles the laptop keyboard and it is square in shape. This keyboard is composed of fewer key and do not have detach numeric keypad.
The multimedia keyboard is specially designed for the people who are much into multimedia designing. This keyboard is just like the standard key board, but composed of additional keys for the multimedia purposes such as multimedia application launch, volume control and mute button.
The Internet keyboards are designed for wider range of multimedia applications, these keyboards are specially designed for the intense Internet user. The special keys included in this keyboard are the home key, back and forward key, e-mail launch key, and browser launch key etc. these keys carry out the same functionality as of the buttons on the webpage. In order use these extra keys the computer must be embedded with right operating system.
A wireless keyboard, the name itself doles the meaning that this keyboard can be operated without addressing a wired connection to the processor. The wireless keyboards are also referred as Cordless keyboards; these keyboards require batteries to provide the electricity which usually delivered through a PS/2 or USB cable. “AA” or “AAA” batteries are most widely used standard batteries for wireless keyboards. Apple Macs are known to revolutionize the wireless keyboard by making them thinner than the wired ones. These keyboards usually work at 2.4 GHz frequency and come with a dongle that connects and makes them communicate with the computer.
As the name suggest, gaming keyboards are those who are into gaming and need easy access to the keys that are usually utilized in gaming. These keyboards are composed of particular gaming-oriented features such as key lighting, programmable keys, and/or extra controls of volume and brightness. These keyboards are available in wired and wireless, in case if wired, it usually supports the USB port.
Membrane keyboards are one of the keyboard types, which are used very rarely. The keys integrated in this keyboard are non-moving pressure-sensitive keys. The keys in this keyboard are so close, so that there is no scope for spilling liquids into the keyboard. Such keyboard types are also used in mobile phones and old landline phones.
Keyboards are slowly being incorporated into touch screens that are being widely incorporated in various phones and tablet computers. Named as touch screen keyboards, these are virtual keyboard units have a QWERTY and numeric appearance so that message typing and number calling are quite easy. Also, gaming consoles that provide social networking such as the PlayStation 3 have an on-screen keyboard which can be accessed by user joystick.