INTRODUCTION
Virtual Keyboard is just another example of todayâ„¢s computer trend of Ëœsmaller and fasterâ„¢. Computing is now not limited to desktops and laptops, it has found its way into mobile devices like palm tops and even cell phones. But what has not changed for the last 50 or so odd years is the input device, the good old QWERTY keyboard and the virtual keyboard technology is latest development.
The new virtual keyboard technology uses sensor technology and artificial intelligence to let users work on any surface as if it were a keyboard. Virtual Keyboards lets you easily create multilingual text content on almost any existing platform and output it directly to PDAs or even web pages. Virtual Keyboard, being a small, handy, well-designed and easy to use application, turns into a perfect solution for cross platform multilingual text input.
The main features are: platform-independent multilingual support for keyboard text input, built-in language layouts and settings, copy/paste etc. operations support just as in a regular text editor, already existing system language settings remain intact, easy and user-friendly interface and design, and small file size.
QWERTY KEYBOARDS
Inside the keyboard
The processor in a keyboard has to understand several things that are important to the utility of the keyboard, such as:
¢ Position of the key in the key matrix.
¢ The amount of bounce and how to filter it.
¢ The speed at which to transmit the typematics.
The microprocessor and controller circuitry of a keyboard.
The key matrix is the grid of circuits underneath the keys. In all keyboards except for capacitive ones, each circuit is broken at the point below a specific key. Pressing the key, bridges the gap in the circuit, allowing a tiny amount of current to flow through. The processor monitors the key matrix for signs of continuity at any point on the grid. When it finds a circuit that is closed, it compares the location of that circuit on the key matrix to the character map in its ROM. The character map is basically a comparison chart for the processor that tells it what the key at x,y coordinates in the key matrix represents. If more than one key is pressed at the same time, the processor checks to see if that combination of keys has a designation in the character map. For example, pressing the Ëœaâ„¢ key by itself would result in a small letter "a" being sent to the computer. If you press and hold down the Shift key while pressing the Ëœaâ„¢ key, the processor compares that combination with the character map and produces a capital letter "A."
A different character map provided by the computer can supersede the character map in the keyboard. This is done quite often in languages whose characters do not have English equivalents. Also, there are utilities for changing the character map from the traditional QWERTY to DVORAK or another custom version.
A look at the key matrix.
Keyboards rely on switches that cause a change in the current flowing through the circuits in the keyboard. When the key presses the keyswitch against the circuit, there is usually a small amount of vibration between the surfaces, known as bounce. The processor in a keyboard recognizes that you pressing the key repeatedly do not cause this very rapid switching on and off. Therefore, it filters all of the tiny fluctuations out of the signal and treats it as a single keypress.
If you continue to hold down a key, the processor determines that you wish to send that character repeatedly to the computer. This is known as typematics. In this process, the delay between each instance of a character can normally be set in software, typically ranging from 30 characters per second (cps) to as few as two cps.
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