Anti-ghosting, N-key rollover, and other terms may have appeared when researching the various keyboard types while trying to purchase one (whether it be a membrane keyboard or mechanical keyboard). What exactly is keyboard ghosting, and why should you be concerned with a keyboard that claims to be anti-ghosting? We’ll cover everything you need to know about keyboard ghosting in this post, including its causes and solutions. So continue reading to learn more about keyboard ghosting.
What is Keyboard Ghosting?
When a user hits a key and it doesn’t register, this is known as keyboard ghosting. If you push many keys at once on some keyboards, some of those keys may not function or appear on the computer screen. The fact that you depressed the keys but they did not show up on your screen indicates that they vanished and are referred to as having ghosted.
Keyboard ghosting is a frequent issue encountered while gaming. When playing a game, you frequently hit multiple keys simultaneously to carry out tasks like strafing while changing firearms or running while shooting.
What Causes Keyboard Ghosting?
The question of why ghosting occurs in the first place arises now that we are aware of what ghosting is. We must quickly review the operation of keyboards in order to comprehend this. A detailed examination of a keyboard’s internal mechanisms is outside the purview of this essay, but I’ll go over the essentials anyway. It will help us comprehend the causes of ghosting.
-
Keyboard Design
Typically, a keyboard has a grid of column and row wires running underneath the keys. By default, these wires are not connected. Nevertheless, each time a key is pressed, the circuit is activated, and the programme can identify which key was hit based on this connection.
Take a look at the illustration below to get a better idea of this.
Photo credit: Microsoft
S is depressed in the image up top. Which column wire has a row wire linked to it can be determined using the keyboard. When it discovers it, it can recognise that keypress (in this case, the second column is shorted by the third row, which means you pressed the S key).
-
Pressing Multiple Keys in an Indistinguishable Circuit
The same technique can be used to programme keyboards to recognise two-key combos and even some multi-key combinations without ghosting. Let’s examine an instance when the keyboard is unable to determine which keys are being pressed, though.
Keyboards can typically uniquely detect key presses even when several keys are hit simultaneously. Nevertheless, some key combinations can confound keyboards. Look at the image below to see where the user touched the three keys indicated by the red dots. Picture provided by Microsoft
The keyboard in this instance registers not just three key pushes, but additionally a fourth keypress due to the way the circuit is finished. The keyboard can detect that the row 3 and row 4 keys in column 2 have been depressed. It can also detect the pressing of a row 4 key in column 3. However, since the circuit is complete, it also seems as though a row 3 key in column 3 is likewise hit.
What are Anti-Ghosting Keyboards?
Thus, since any of the following key combinations could be true, the keyboard has no means of knowing which of these four keys you actually pressed. Keyboard ghosting occurs when the keyboard stops registering all key presses in order to stop itself from reporting incorrect key presses.
- Keyboard makers can rearrange the wires in the keyboard so that key combinations that are often used together don t exhibit these issues.
- Use extra wires to prevent ambiguity while pressing key combinations.
- A diode can be used on every key to register them individually.
So how do we approach this fundamental keyboard design problem? It turns out that manufacturers have three options for addressing the ghosting problems.
Even while the first approach is perhaps the simplest, it doesn’t completely resolve the issue. It merely shifts the ghosting problem to an other group of keys, which are probably less frequently used together and might go undiscovered. Many anti-ghosting keyboards employ this technique. A keyboard from Cooler Master that prevents ghosting
All Anti-Ghosting Keyboards are Not Created Equal
Contrarily, the second approach resolves the issue. However, adding more cables necessitates creating more circuitry for the keyboards, raising the cost of the keyboards. Although installing a diode for each key on a keyboard would be incredibly expensive, it might also solve the problem.
What is N-Key Rollover? Is It the Same as Anti-Ghosting?
Many times, keyboard makers will claim that their keyboards are anti-ghosting, however this just tells a portion of the truth. Anti-ghosting keyboards frequently only address the ghosting problem for key combinations that are frequently pressed together. That implies that the issue persists for other key combinations that are (often less frequent). That is acceptable up to the point when you use key combinations that actually experience ghosting and discover that your keyboard is no longer functional.
N-key rollover is another expression you’ll frequently come across when looking for keyboards. This is typically found on gaming keyboards or even gaming computers. What does N-Key rollover actually mean? Does it function the same way as anti-ghosting?
No, is the response. The N-key rollover is unique. If a keyboard has N-key rollover, you can press any number of keys at once without experiencing any problems. All key presses on the keyboard will be recorded. N key rollover on a BenQ keyboard
But as you may have already surmised, N-key rollover is essentially useless without anti-ghosting methods. To consistently support pressing any number of keys simultaneously without any problems or false positives, a keyboard must include anti-ghosting.
Keyboard Ghosting, Anti-Ghosting, and N-Key Rollover Explained
Therefore, having N-key rollover is something you should watch out for when purchasing a gaming keyboard. If you play games that demand you to simultaneously hit many keys, it is very crucial.
