The Keyboard - Debut

Basic Terminology & Types Of Feedback

There are many different types of keyboards out there, but I'll only try and cover the three biggest – dome-switch, scissor switch and mechanical keyboards. But first, in order for one to fully comprehend the text below, one has to know the basic terminology:

Bottoming Out - When the switches are depressed all the way down
Compact Layout - Some keyboards have approximately the same number of keys as a fullsize keyboard but are laid out in a different way to reduce width.
Double Tap - Gaming technique where you hit the key rapidly sending multiple keystrokes.
Linear - A switch that has no tactile 'bump' - the resistance increases in a linear fashion along the travel of the key.
N-key rollover, NKRO (also 6KRO, 2KRO) - The ability to hold down multiple keys at once. Important mainly for gaming.
PS/2 - Introduced with the PS/2 IBM systems in 1987 this became the method of connecting mice and keyboards for many years. Now slowly being phased out in favor of USB.
Tactile point/Tactile force - Similar to the Activation point/Activation force point but at the top of the tactile "bump".
Tenkeyless - Term for keyboards that don't have a numeric keypad section and are therefore narrower and some say more ergonomic. Some have embedded number pads in the right portion of the main key cluster like some laptops.
Travel - "Key Travel", "Switch Travel". The distance the key travel from the top of the stroke to the bottom. Basically how much the keys move when you press them down.


Explanation of the difference between keyboard feedbacks

Tactile refers to the feedback you get using some mechanical keyboards. You can feel a "bump" as the switch is activated. Sometimes in addition the switch makes a distinctive "click" sound somewhere in the middle of the key stroke. You are using a tactile and clicky mechanical switch right now. It is your mouse button.

Now that 75 gm is a bit stiffer than your typical keyboard and obviously has a lot less travel. Travel is the distance the switch can go from when you are lightly resting your hands on the keyboard to the bottom of the stroke as you bang out a term paper or blast an alien. A typical mechanical switch allows you more travel than a rubber dome (around 3mm usually) or scissor switch (a little over 2mm).

As you press down the spring resists your finger until you reach what is called the "tactile point" or "tactile bump". At or near the same time you hear a "click". That is what is meant by a tactile and clicky switch. Not all switches click. Not all switches have a tactile bump, they feel you are pressing a spring - a gradually rising force. This is called "linear" in switch terms. Go ring an old fashioned doorbell. It's a linear switch - you don't feel a bump. (geekhack.org, September 2011)
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