Computer Keyboards

Introduction

The computer keyboard is possibly the world's most ignored peripheral. Computers arrive with a disposable keyboard - whether it's the $5 one sent with a desktop computer, or the chiclet key one built into your laptop. Then you sit at a desk and subject your hands to this piece of garbage for four to ten hours a day. Spend some money and improve your life!

Mechanical keyboards are all the rage these days - this makes me feel a little better about the world, but the people who're interested in the subject are still a minuscule percentage of the world's computer-using population. I admit that if you're travelling with a laptop, carrying an external keyboard is awkward (I rarely do it myself): but if you have a fixed workspace, you should get a good keyboard and mouse.

I should also point out that there are literally thousands of rants like this one on the internet, and some of the others are better informed and less biased. So you may be better served elsewhere: I'll endeavour to at least be factually accurate.

The Dvorak Layout

Dvorak keyboard layout

My interest in keyboards started back in 1994-5 when I trained myself to type on the Dvorak keyboard layout (I originally learned how to type on an actual typewriter in 1983). I never got over about 35 wpm with the Scholes/QWERTY layout, but with Dvorak I can manage about 55 wpm. It wasn't long after that that I developed a taste for the feel of the notorious and widely loved IBM Model M keyboard. For those not familiar with it, the IBM Model M weighs approximately 2.3 kg (5 pounds), and is every bit as indestructible as that weight would suggest. It's got a solid metal back plate through the whole body. But that's not why keyboard enthusiasts treasure it (although it doesn't hurt ... unless of course you drop it on your foot). The Model M has buckling spring keys. These are possibly the best feeling keys for typing on on the face of the planet. They're also fantastically loud and your co-workers and/or family will hate you, but you can't have everything.

Split Keyboards and Straight Key Columns

As with any such quest, I kept searching for "better." I had wrist problems related to typing, and eventually concluded that the rising right-to-left key slant that keyboards inherited from typewriters for no good reason at all (the slant is to accommodate the lever arms under the keys in the typewriter) was causing my left wrist to be bent too far left. Likewise, forcing your hands close together also caused bending of both wrists, so I'm a fan for split keyboards with straight key columns. As it turns out, these are quite rare. There are lots of split keyboards, but straight key columns are uncommon. Happily, there's the Kinesis Advantage keyboard: it wasn't until 2007 that I was willing to spend the $350 to buy the damn thing (I now own three - one for home, one for work, and one I found at a computer junk store for $15 ... - so you can assume that I've finally found "better").

Kinesis Advantage keyboard

Kinesis went a step farther than I had, and decided that since your fingers vary in length, the keys for the longer fingers should be farther away than those for shorter fingers. This means less travel for all your fingers as you type. They've also made more use of the thumb because it's the strongest digit you've got. Keyboards - like anything - are cheaper when they're manufactured in bulk. Kinesis has lumbered themselves with a keyboard that's not only relatively low production because it's so "weird," but also very much more complex to construct - resulting in the extraordinarily high price. Despite which I highly recommend them: they're very well built, last for years of heavy use, and their returns department immediately sent me replacement parts free of charge the only time I ever had a problem.

Keyboard Key Switches

You should read this: https://en.wikipedia.org/wiki/Keyboard_technology . I'm going to cover some of it, but take a quick look at the "Dome-switch keyboard" section and the "Scissor-switch keyboard" section. These are by far the commonest types of keyboard switches - mostly because they're cheap.

The Buckling Spring Key Switch

I've already mentioned buckling spring keys, let's look at what makes them work as an entry point into the subject of mechanical key switches:

Buckling spring key switch animation Buckling spring key switch animation

This is an old graph with Imperial measures, but you get the general idea. As you press the key down, the slightly off-centre spring underneath the key buckles out to the side. When the spring buckles, the down-force required suddenly drops, and the actuator plate completes the circuit (underneath it all is a dome-switch), giving a very clear indicator of when you've actually activated the key. Popular among keyboard geeks, the force-distance graph can give you some slight idea of what the key feels like (I said "slight" - you need to feel it for yourself). One other important feature of the buckling spring is the very distinctive clunk/ringing noise it makes when the spring buckles and hits the inside of the sleeve. Typing on a Model M is loud, and people near you may not appreciate the happy experience your hands are having.

Buckling spring keyswitches live on, manufactured by Unicomp, who bought the right to build these keyboards from IBM: http://www.pckeyboard.com/. You'll notice they don't sell split or vertical column keyboards, so I make do with my old Model Ms if I need that buckling spring feel. You can also occasionally pick up the Model Ms - from your neighbour's trash (although that's less common these days), at Value Village or Salvation Army, or on eBay (prices vary wildly). If you get a real Model M, you'll need a PS/2-to-USB converter (or worse, DIN-to-USB) to make it work with modern computers.

Cherry Key Switches

Kinesis uses the Cherry Brown key switch. If you delve into the world of mechanical keys, Cherry is a name you're going to hear a lot - they're not the only manufacturer of mechanical key switches (Topre and Alps being other examples), but right now they're the best known and most readily available. Knowing about the various colours is essential.

Their switches are classified by three characteristics:

  1. whether or not it's "tactile" (the feel)
  2. auditory feedback (clicky or quiet)
  3. activation force (how hard you have to press to move the key)

Kinesis makes the argument that lower activation force means less RSI: I'm not convinced they're right about that, but I admit I haven't gone looking for the research, and they may actually have done so. So let's talk about measuring force ... A "newton" is "the force needed to accelerate one kilogram of mass at the rate of one metre per second squared." Keyboard activation is almost always measured in centiNewtons, or "cN", 1/100th of a Newton. The Cherry Brown requires 45 cN to activate, the Model M buckling spring requires 63 cN.

Let's consider the three main types of Cherry keys:

Cherry Brown switch animation Cherry Brown Activation Force graph

This is the Cherry MX Brown, possibly their most common switch. Notice the spring bumping over a part of the key plunger as it descends: this provides tactile feedback. These aren't the "clicky" keys, but they're a long way from silent. The Cherry MX Clear is essentially identical in build, but has a stronger spring - they're often used with Brown-equipped keyboards for the space bar. The Brown activates around 45 cN, the Clear around 55 cN.

Cherry Blue switch animation Cherry Blue Activation Force graph

The Cherry MX Blue has an extra sleeve around the plunger: you get both a tactile bump and a click, and a somewhat different (to my mind better) feel. This makes it very clear as you press the key when the key has actually activated. The Cherry MX Green is essentially identical, but has a stronger spring and thus a higher activation force. The Greens are also much harder to find to purchase (although they're becoming commoner in specialty keyboards). The Blue activates around 48 cN, the Green around 68 cN.

Please note: the image below is a Cherry Red, the graph is for a Cherry Black: the Red graph is identical in shape but requires slightly less activation force.
Cherry Red switch animation Cherry Black Activation Force graph

(The "Black" image doesn't show what's going on, because ... everything is black. So I chose the red image. But I couldn't find a good copy of the Red graph - thus the mismatch, sorry.) The Cherry MX Red and Black switches are what are known as "Linear." They have no click and no tactile bump, and the only way to be sure you've activated them is to bottom them out. I hate them, but they've proven popular with gamers. The Red activates at 45 cN, the Black at 60 cN.

One of my Kinesis Advantage keyboards still has the original Cherry Brown switches in it, but I've modified both of the others. One has Cherry Blues, the other Cherry Clears. Initially, the Clears just feel like a slightly stiffer Brown and it seems like no big deal. But I found after typing on them for several hours it became quite tiring. I greatly prefer the Blues to either the Clears or the Browns. I'd like to try the Greens (although the activation force is high, they've felt good when I tried them at the store): as mentioned, they're hard to get. And I'll also admit that I like the Blues as being most similar to the Buckling Spring keys: I would buy Buckling Spring keys if they were available as individual key switches.

Mechanical key switches are expensive: they tend to be in the neighbourhood of $1 each even in bulk, so a mechanical keyboard often carries a price tag of $80 to $200 (although at the high end of the scale they often include unnecessary extras like full LED lighting).

Where to Start

If this sounds interesting to you, the best thing to do is go to Canada Computers (if you're in Ontario) and try the keyboards. They usually have a lot of specialty keyboards available to test. My favourite low-end mechanical keyboard is the CM Storm ("by Cooler Master") "Quick Fire Rapid," which is a small (no numeric keypad) keyboard with Cherry Blue key switches that could be had for about $80. It's well built and feels great. I don't think CM sells it anymore - it's been replaced by something that looks and feels the same, but costs a lot more because it now has LED lighting.

Another thing you should consider if you buy a Cherry-based mechanical keyboard is the o-ring dampers available from wasdkeyboards: all the Cherrys, particularly the Blues and Greens, are subject to clicking, and if you tend to bottom out the key they'll bang when they hit. A (frustrated) friend at work sponsored my purchase of a set: they don't make the keyboard silent, but it's a significant improvement. They're available here.

Other Keyboard Topics Not Addressed

  • other mechanical key switch manufacturers (Topre, Alps, etc.)
  • N-key roll-over
  • build quality
  • soldering and building your own

Bibliography