Sonic's Desktop

The computer keyboard

In our last two editions, we looked at input devices which serve the purpose of pointing to a specific location in the interface. If you are still unfamiliar with the word 'interface', it simply refers to what you can see through the computer monitor.

Earlier, there weren't all these fancy graphics like today. All the commands had to be given in text. This was a big obstacle in the computer becoming popular among average users. However, we will be looking at Operating Systems in a later edition and this will become clear to you then. All of you must be familiar with the mechanical typewriter.

With the development of computer technology, this was modified and used as a device to input data into a computer. This is how the keyboard came into being, and it is one of the oldest devices to be used in conjunction with the computer to input data.

Let's look at some important facts about computer keyboards today. When we take the layout of buttons of the keyboard, generally they are a set of rectangular buttons and most of the keys correspond to a specific character like in the mechanical keyboard.

But, the difference is that instead of a mechanical operation, electronic data is sent to the computer. Apart from the keys used to input characters, there is also a set of keys which send signals relevant to the control functions of the computer.

The Function key that you see on the top of the keyboard with numbers ranging from F1 to F12, the arrow keys etc are such keys which help to control the computer. There is also the possibility to have key combinations to perform some action.

This means that two or more keys can be pressed together to send the computer commands to perform some action. For example, if you are using the Windows Operating System, Alt+F4 will close the window that is active at that moment.

When you are using a word processing software, Ctrl+S saves the document. Ctrl+P sends the command to print the document. Likewise, there are a vast number of key combinations generally called 'keyboard short-cuts' to perform a variety of actions.

Operation of a general keyboard

Have you ever dismantled a keyboard? If not, just try it some other time with someone’s guidance if you are not sure about it and you will see that it looks very simple inside the keyboard. There is a very small piece of circuitry below the keys; there are many lines which can carry small signals.

These paths are broken in the middle and what happens in the keyboard is that when you press a certain key, it bridges the gap between the two points and makes the current flow. Now comes the job of a chip in the small piece of circuitry, I mentioned before. A scanning signal is emitted by the chip along the pairs of lines to all the keys.

When the signal in one pair becomes different, the chip generates a “make code” corresponding to the key connected to that pair of lines. The code generated is sent to the computer either via a keyboard cable or over a wireless connection.

A chip inside the computer receives the signal bits and transforms them into the correct keypress.

Alternatives to traditional keyboards

Although many devices became small with the development of technology, the keyboard was not miniaturised as

 such. That is simply because it is not possible to do so, since each key should be large enough to be able to press using a finger.

However, there are a few alternatives by now to this original design. One method is ‘chording’. In this method, there are a few keys, and a character is given by pressing one or more keys. The latest is the ‘laser projection keyboard’.

In this design, the image of a keyboard is projected to the surface of where you work. Sensors pick up finger movements and identify the keys pressed. The Maltron keyboard is a new invention which eliminates a few problems with the conventional design.

The traditional keyboard restricts wrist movement and causes a disease called ‘carpal tunnel syndrome’. The Maltron keyboard is designed to avoid this as well as some other strain injuries that may happen by using the

keyboard.

There are several models of the Maltron keyboard such as 3D, Single Handed, Single Finger and Executive.

Signing out for now
Aravinda Dassanayake