Enhanced layout
Provided by the ASK Keyboard Dictionary
![](resources/images/layouts/shark_enhanced_101_units.png)
The Enhanced layout refers to the key arrangements that are de facto standard on current PC keyboards. It was developed from IBM's 122-key typewriter keyboard layout with some external influences such as from DEC's terminal keyboards. It was cemented by the Model M-based IBM Enhanced Keyboard from 1985. Following the success of the IBM Personal System/2 and adoption by my PC clone manufacturers, the Enhanced Keyboard's 101-key "ANSI" and 102-key "ISO" layouts both became the standard that most full-size or tenkeyless keyboards derive from albeit with the inclusion of Windows/GUI and menu keys that bring the full-size key count up to 104 and 105 keys for "ANSI" and "ISO" respectively.