There are many different keyboard layouts, both as regards the placement of the keys and in terms of those keys on the placement of the letters. The placement of the letters (and therefore different formats such as QWERTY and AZERTY) has its origin in the mechanical typewriter, where the layout prevented hammers terminal got stuck. The latter could happen when adjacent keys were struck quickly in succession; Therefore, the tests were organized to letters often followed each other, could not be easily excited quick succession. Since the advent of electronic typewriters and computers, this is no longer relevant, but in practice it has retained the old keyboard layouts. Newer keyboard layouts designed for ease of use, such as the Dvorak keyboard, used only very limited.
In the Netherlands, mostly keyboards with the US, "American International" (ANSI) format sold. This is one of the so called QWERTY' formats, named after the first six letters of the upper letter keys row. The abbreviation ANSI refers to the mechanical layout of the keyboard. When the keyboard has a small ENTER key, then the mechanical layout usually the type ANSI.
For the connection of keyboards, there are some possibilities. Nowadays, non-wireless keyboards only USB and PS / 2 are common. At the first PCs were previously using a DIN connector, the same five-pin plug which is also known stereo equipment.
The security of information plays a role in low-cost and older wireless keyboards. Thereby sometimes sent unencrypted data via radio waves. This could be taken care of by a person so as to identify passwords. With good wireless keyboards data versleuteld.Ook be if there is a fixed connection (not wireless), it is sometimes still possible to detect the keys pressed by radio. Some keyboards with a PS / 2 connector produce so many radio waves (in fact interference) that are catching on that waves up to several meters.
With a good ergonomic construction of a keyboard typing errors made can be minimized. About the ergonomics of keyboards is little clarity, but important aspects are:
- button size and button placement
- keyboard height and angle of inclination with respect to the desktop (somewhat adjustable by the supports at the bottom side of the board)
- force required to press a key
- clear tactile 'click' when pressed
Often it is a personal choice which keyboard is best.
An adjustable keyboard
Ergonomic keyboards also serve to prevent RSI. The simplest solution is to rotate the group keys for the left hand which tilted to the left and group keys for the right hand which tilted to the right. By fabricating the two parts separately from each other, the user can adjust the angle. Sometimes also the function keys for the user tilted, so that they can be pressed without moving the hands. Finally, there are special keyboards with only a small number of keys, placed exactly under the fingers, which, for most of the letters needs to be pressed in a certain key combination (instead of a single key).