Keyboard basher

Features Mark Pickavance Jan 22, 2013

Mark Pickavance talks about the joy of mechanical keyboards and what you need to get a good one

A typical review that I write here in Micro Mart contains around 3,000 characters (more if you include spaces), and on average I write about 500 pages a year. That works out at around a quarter of a million words and at least 1.5 million key presses. Factor in other publications and keyboard use and we’re probably closer to 450,000 words and three million key presses, which explains why, after about six months of typical use, the vowel key-tops on my keyboards are polished to the point that they’re all but unreadable.

However, it’s not just the keyboard that takes a beating on my desk: what’s happening to my fingers? That’s a concern, which is why I’ve taken the step of finding out what the best keyboards are and what the technology behind them is.

Why so mechanical?

I’ve noticed that lots of laptop makers these days don’t care for mechanical keyboards, usually because they cost more, but also the key travel on them makes the machine thicker. Some of these designs, like the ones that Microsoft has offered on the Surface, use two electrical contacts separated by a stiff membrane, which the pressure of your finger brings together to complete the circuit.
The problem with this method is that there is no obvious physical feedback when the key transitions between not pressed and pressed, so to make sure you register a press you’re inclined to use more force than is really needed. That can cause damage to both the tendons in the fingers, muscles and also the joints, which can eventually lead to long-term damage and discomfort.

The best keyboards, and the ones that allow you to type rapidly and accurately, are mechanical ones, because they register the key press before they’re fully depressed, which reduces the wear on you, importantly. 

The worst possible keyboards for comfort are those on the screens of tablets, where you are effectively smashing the end of your finger into a hard surface repeatedly. Those that input more than short messages on their tablet need to seriously consider buying a Bluetooth keyboard, before they irreparably damage themselves.

Important keyboard knowledge

If advice on keyboards was as simple as ‘get a mechanical one’, then this would be a short article that wouldn’t be remotely interesting. However, there are lots of variations within the making of keyboards that can dictate if the design is right or not for you. For starters, should you go for a USB or PS/2 type?

Since it came along, USB has become the standard for keyboards, as systems come with multiple USB ports and you can have a desktop hub that makes your cabling much less complicated. Older systems use the PS/2 connector, which is older than the hills, so which is best? PS/2, amazingly.

The way that USB works means that the system must poll the keyboard to find out if a key has been pressed and, depending how busy the USB bus is, those polling actions might feasibly miss a press. There is another USB mode which is interrupt driven, but the expense of providing this means it’s never used on keyboards.

Alternatively, PS/2 connection is inherently interrupt driven, so when the key is pressed a small CPU in the keyboard sends a message to the main CPU to the effect that key ‘X’ was pressed. That allows them to exhibit something called NKRO (N-Key Rollover). A USB keyboard can only be polled for a set number of simultaneous keys being pressed and any more are ignored. Most USB keyboards will only see four different key presses at any one time, although they might also see one of the Ctrl, Alt, Shift and the Windows command key in addition to the four ordinary keys.

Better USB keyboards can be labelled at 6KRO, meaning they can poll six ordinary keys and they also can see four special ‘modifier’ keys in addition. These are better, but they’ll never be as good as an interrupt driven PS/2 keyboard that demonstrates proper N-Key Rollover, which USB can’t achieve currently.

Ghosts in the machine

Some keyboards are sold as "anti-ghost", so what’s that all about? There’s a situation that can happen when two keys are pressed at exactly the same time, where the system generates a third key you never pushed: the ghost key. This is rare, but it can happen.
To stop this odd occurrence some keyboard makers have instigated a form of software blocking that eliminates the extra key press, but the downside of this is that it ignores that third press if it really happens too, which is yet another problem.

This a limitation of the wiring matrix that reads the keys and, as such, is difficult to combat entirely. The most common place you’ll encounter ghosting or blocking is in gaming, rather than editing text. As such, most of the keyboards with anti-ghosting tech are those designed for this purpose. What they usually do is treat the WASD area of the keyboard as special, so all simultaneous keys in this area are read, but it doesn’t mean that the keyboard can handle any input combination without error.

The problem is more of an issue on USB keyboards, because of the limitations on the number of keys that can be simultaneously sensed, but even PS/2 ones aren’t entirely immune because of the matrix on which the keys are electrically connected.

The bounce

As a key is depressed, it eventually triggers the switch underneath, and from the perspective of the computer the contacts bounce to register multiple key presses. This is true irrespective of what mechanism it is, and it’s something the system must cope with or typing would be something of a nightmare. The way that this is handled is that once a key press is recognised from a single key, then for a period of time further input from that source is ignored until the key is considered ‘reset’. This is called the ‘debounce’ and the better the keyboard the shorter this time is.A good mechanical mechanism like one based on the Cherry MX switch has a debounce of 5ms, where a cheap keyboard might be a lot longer. The faster you’d like to type, the shorter a debounce period you’ll need and want.

Mechanical keyboards always have shorter bounces than those with rubber domes or other flattened designs, and it’s one of the reasons that they’re better. However (and this is the catch), the springs that create short bounce can also make these key actions noisy.

Time to switch

When you start looking for keyboards you’ll hopefully be told about exactly what switch the product you’re looking for uses. The snag with this information is that most people don’t know a Cherry MX Black from a Black Alps, unless they’re a hopeless geek like me. 

What’s important to know about these mechanisms in respect to use is that switches like the Cherry MX Black are considered good for gaming, because they’re not tactile and the tactile ones are generally better for typing. Personally, I’d avoid the Alps design because it has a hard ending to the press with no pre-activation, which can hurt you after extended use. I’ve not tested them, but I’ve heard excellent things about Topre switches, which depending on the specific keyboard can have a range of activation forces, and they’re also very quiet (not being clicky).

There are others, but these are the ones that are usually quoted, and it’s worth understanding what the difference is between, say, a Cherry MX Blue and a Red. Understanding the switches can avoid you ordering a keyboard that’s entirely unsuitable for how you intend to use it.

Top that!

I’ve talked about how the keyboard connects to the PC and the switch under the key, but I haven’t yet covered the physical key top. As this the part you actually strike, it’s important to understand that you can see plenty of variations here.

The top of the key is usually shaped in one of three different styles; flat, spherical or cylindrical. The flat key looks nice but is the worst design, because there’s no touch feedback to tell you if you’re hitting the key in the centre or off to one side. Dished designs train your fingers to hit the centre, improving accuracy, and most keyboards come with cylindrical depressions. It’s normally only old typewriter designs that use spherical, because it tends to make the key top smaller, and therefore harder to hit cleanly.

Whatever their shape, the keys themselves are usually made from either ABS (Acrylonitrile Butadiene Styrene) or PBT (Polybutylene Terephthalate) Plastic, although Apple has made a few that had metallic tops to them. If a choice is available, then PBT is harder wearing, though it usually costs more accordingly. How the key reacts to repeated use is also affected by the means that the keyboard maker uses to mark the key top.

The cheapest method, and the one that Microsoft likes is called pad printing, which looks great for five seconds and is invisible just a few months later. More hard wearing is laser etching, but the results of burning plastic using coherent light aren’t as aesthetically pleasing as other methods, and can make the key top uneven.

The two preferred methods are either dye sublimation or double-shot injection moulding. Both of these produce keys where the letter doesn’t get rubbed out, but they also look sharp and you can’t feel the letter form with your finger tip. The snag is that both these are only available on keyboards that cost the most.

Having explained what to look for in a keyboard, let’s look at some popular designs and connect the dots, so to speak.

Filco Majestouch (£100 +VAT from the Keyboard Company)

This is a classic design that uses Cherry MX Black switches and it’s a USB design with a PS/2 converter supplied along with it. The 60g activation force and the 2mm activation point make this potentially ideal for gaming, but the linear action is also good for typing too. What’s especially nice about this design is that you can buy a key puller for the Flico design, and replacement tops when they’re needed. It might seem like lots to spend on a keyboard, but it’s an investment. You can get this design with other switches, if you’d like a different feel.

Qpad MK-85 Red LED Pro Backlit Mechanical Gaming Keyboard (£109.99 from Overclockers UK)

As gaming designs go, this is one of the more striking, and also rather expensive. What’s certain is that you’ll be able to identify all the keys even in complete darkness due to the LED backlighting on each individual key. Qpad used the Cherry MX Brown switch on this model, and it comes with four special orange keys, which you can replace using the provided key puller.

Cherry G80-3000 Mechanical Keyboard (£64.99 from Overclockers UK)

This is another keyboard that uses Cherry switches, this time the MX Blue. As such, this is aimed more specifically at those who type long documents on a regular basis. This is almost an identical design to a Das Keyboard that shares many of the parts but costs twice as much, so the G80-3000 is something of a bargain at this price.

Topre Realforce 105UB Variable Gold on Black (£192 from The Keyboard Company)

This is an expensive design, but it’s a very sophisticated keyboard that uses Topre switches. Where most keyboards have the same switch on every key, the Realforce 105UB has a range of actuation weights according to where on the keyboard the key is, reducing typing fatigue. Sadly, this only comes with USB, but it’s hardly a gaming keyboard so that’s not a big issue.

SteelSeries 6G v2 Mechanical Gaming Keyboard (£74.99)

I’ve included this one, because it’s the keyboard I’m actually using to write this, and it’s not bad for typing even if it’s specifically built for gaming. It uses the ever popular MX Black switches, though it’s been rumoured that SteelSeries might release the design with alternative switches at some point. It comes with a USB to PS/2 adapter, and it has excellent anti-ghosting technology. The only downsides to this keyboard are that it’s invisible in the dark and laser etched key tops do wear eventually.

Where to find the best ones?

If you have a particular design in mind, say something by SteelSeries, then there are many online retailers and stores that will offer you those. However, true aficionados will often seek out a supplier who specialises in the very best keyboards and can even provide replacement parts to keep a much loved input device in perfect working order.

Most online retailers carry the standard gaming keyboards from the likes of Logitech and Steelseries, but if you want something more sophisticated, then you might need to look for a specialist distributor of input devices. One of these is The Keyboard Company (www.keyboardco.com), which has a fantastic range of keyboards with all the information about the switches used in each. It stocks Realforce, Filco, Seal Shield, Matias and Cherry keyboards among others.

My only concern about buying keyboards without first-hand experience is that you can so easily be disappointed by a design that looked ideal on paper but less wonderful on your desk. Some direct experience is ideal, unless you already have a design that you’d like to replace.