Mechanical Keyboards 101, Part Three: Layout, Format, and Form Factor

Posted: March 29, 2017 in keyboarding

In this episode, I’ll take you through some of the most common keyboard layouts, formats, and form factors. I’ll even do a bit of historical meandering, just because that can be fun and educational.

Let’s get to terms.

Layout: This refers to the placement, size, and shape of the keys you’ll find on the ‘board. The most frequently seen layout in the U.S. is the ANSI layout. It is easily recognized by the rectangular “Enter” key that is one one row wide, and just a shade longer than the backspace. With this layout, the “backslash and pipe” key is one and a half units wide, and the backspace key is more like two units wide.

In Europe and some other locales, they prefer the ISO layout, which has an “Enter” key that is taller, but narrower. This displaces a few keys, and makes jumping from one to another a bit of a learning process. Typically, an ISO keyboard changes the shape of the right shift key a bit, and will move the location of the “backslash and pipe” key around to make room for the tall enter key.

Other places around the world have a few other layouts they use. Japan, for instance, has its own standard, the JIS layout. These layouts are often based upon the ISO or ANSI, but modified to fit the intricacies of the language in question.

In the past, keyboards have featured the AT and the XT format. These were early precursors of the formats we see now, and lacked such modern amenities as the Windows key and the Menu key.  For a time in the 90’s there was a phenomenon that has been referred to some as the “Big Ass Enter Key”. This was just as it sounded, with a very large enter key that was as wide as an ANSI version, and as tall as an ISO. It was kinda huge. If you’re of a certain age, you probably remember them. They did often cause the misfortune of featuring a backspace key of normal 1×1 size, which tended to bother those of us who sometimes make typing errors, and want to easily hit the backspace, not some other nearby, random key. Lots of people created a lot of unanticipated plus signs during that era.

These above all assume a QWERTY key layout. However, it’s not a given. There are multiple other methods to layout the keys, and some maintain that they are far better than the familiar QWERTY.

The most common amonng these alternative layouts is Dvorak. There is also Colemak, and a few others I can’t readily name.

Quick story time: The reason that the QWERTY layout was adopted was that the typing hardware at the time consisted of a typewriter. In traditional typewriters, the keys were attached to pushrods that caused an arm to swing upward, striking the face of the key against a piece of paper. Because there were a whole lot of arms that had to swing unimpeded and hit the paper, it was sometimes possible to hit the keys so quickly, in such a way as to cause the machinery to jam up. Two or more arms would get hung up with each other, and all work had to be halted to remedy the situation.

The QWERTY layout put commonly used keys far enough apart that they wouldn’t hang up as often. It also served to slow the typing speed down a bit, because all the most common keys were not right under your fingers. You had to reach for some of them. It caught on, and long after that mechanical concern became lost in the sands of time, we’re still typing on the same format. This is a great example of institutional inertia. It’s the same reason that cars and trucks and trains and the like still use the same track width that they always have. Changing the conception of how wide they are would take too much work. It’s fine. Leave it. Never mind that it’s essentially the same measurement we’ve been using since it was the standard axle width of Roman wagons. <end story time>

Dvorak and other layouts probably have some technical advantages. The only downside is that you’re not always going to have access to the same layout, because it didn’t take hold and become widespread. It’s sort of like knowing a really cool language that no one speaks. It has merit, but isn’t as useful as knowing, say, Spanish.

One final layout to mention, for lack of a better place to put the concept, is the ortholinear key orientation. Most of the time, you’ll see that the keys are graduated in a diagonal, leaning gradually toward the left as you go up the alphanumeric cluster. Because typewriters. Again. Ortholinear layout has them go straight up and down. Less reaching, less movement away from the home row. But. But trying to rewire your brain after years or decades of typing on a graduated ‘board doesn’t happen overnight, and it’ll probably mess up your technique on a regular layout. So there’s that.

Format: In the past, when there were a great many different computing platforms, they all had their own specialized keyboard formats, featuring keys that did specific things in that environment. Especially in the era of terminal computing, where you had giants like WYSE and that ilk producing a lot of the equipment used at data terminals and points of sale, the keyboards were formatted and tuned to the particular set of tasks and shortcuts. This typically had a minimum of impact on the primary alphanumeric part of the ‘board, but everything beyond that was up for grabs. Today, there really aren’t very many formats still seen out in the wild.

PC Format: The most familiar to a lot of people is the PC format, wherein you have keys for control, alt, Windows, and menu. There’s typically a function button layer on top of the alphanumeric cluster, and a set of word processing navigation buttons above a nav cluster (arrow keys) to the right of that. But, I fear that I may have wandered into the territory of form factor now, as the actual complement and number of keys included is more a function of that design choice than any other. It should be noted that Linux computers are set up to run with this PC format, by default. You could remap a few keys if you wanted, but it isn’t required.

Mac: The other one that you’ll see is the Apple Mac format. This format has control, command, and alt…or something. I am not a Mac guy, so I have to wing it when forced to sit at one. Sorry, a little light on the lingo for this segment.

Chromebook: Another format that some might confront is the Chromebook format, though this is less common, and a normal keyboard will work fine with this OS. The Chromebook format does away with normal Function keys, and instead has a variety of keys along the top row that serve particular functions in the Chrome OS. They can work with PCs, to a great extent, though you might find a key or two that you will miss, if you use one long enough.

Form Factor: This refers to the size, shape, and number of keys included in a particular keyboard design. Through history, there have been a ton of different form factors, from nothing more than the alphanumeric cluster on a very compact ‘board, all the way up to keyboards with as many as 160-some odd keys. (yeah, think about it).

Full Sized: This is far and away the most common and familiar form factor for desktop keyboards. Typically, somewhere between 104 and 108 keys are included. Full function row, navigation cluster, and a ten-key are included. (A ten-key is the same as a numeric keypad.) Usually, ANSI layouts have 104, while ISO has 105. The other few keys are typically media shortcuts. Turning the volume up and down, for instance.

“Battleship”: This is a rarely-used format, and the only one larger than full sized that you can purchase new today. Only a few companies make this size ‘board, but they were fairly popular for a few years. Typically, they have around 122 keys. The extras are generally another twelve function keys, and a few other special keys that might be useful to you in some situations. Some gaming keyboards probably fit into this form factor, as they have configurable keys that can be given particular tasks in a gaming scenario. Equipping a weapon, carrying out an attack, looting the corpses. Whatever the game calls for.

Compact Full: This form factor has the same number of keys, but has either squeezed all the dead space out from between the various clusters, or has elected to make some of the keys smaller to save space. Or, perhaps, both things. You’ll see this form factor on laptop keyboards a lot. For instance, they’ll put small navigation cluster buttons below the rest, saving some width. Coolermaster has an interesting take on this form factor called the TK, which is quite similar to the “navless” covered below, but with some clever alterations of the keys that carry out the navigation, to make it a bit more ergonomic to use.

Navless: Quite popular in the days of the XT computers, these would do away with the whole nav cluster and the keys that typically reside above it, allowing toggling between these functions and the numerics with the Num Lock key. This yielded a narrower, more compact presentation. This was an implementation that actually made the Num Lock key matter. Rarely seen today, I think that there’s a lot to be said for this form factor, and I’d be interested in trying a modern iteration, should a company decide to design one.

TKL: This form factor does away with the whole numeric keypad. TKL stands for “ten-keyless”. Roughly the same width as the navless layout, if not just vaguely narrower, this is popular with gamers, as well as with people who don’t find any utility in having a ten-key. The advantage, for a right-handed person, is that it puts the mouse nearer the midline of the body, and cuts down a bit on the wear and tear on your wrist and elbow over long gaming sessions.  For someone who uses the mouse with his or her left hand, there is no real ergonomic upside. The freeing up of a bit of desk real estate is still a viable rationale for selecting one. This form factor is also called the 87% or 87 key size. Other than the omission of the keypad, no other changes are made to key spacing or content.

60% (or HHKB): Some people just want their keyboard to be…smaller. There could be a variety of reasons, but the main three are portability, aesthetic concerns, and possible efficiency gains. An early adopter to the 60% format was the Happy Hacking Keyboard. Along with moving a few keys around (omitting the caps lock in favor of having ctrl in its place), it did away with the function layer, the nav cluster, and the numeric keypad. Thus, you have a much smaller keyboard. It is really just the alphanumeric block and the standard modifiers.

How do you access all the other functions, you may ask. I will tell you. One or more keys are included to allow secondary layers of functionality for the keys still present. Function keys are included in the layout of the keys. Pressing them, much like shift does, allows access to another “layer” of output. This means that each key on the keyboard can output three or even four possible commands, depending upon what is used to modify the keystroke. Fans of this form factor indicate that once you are used to the intricacies, your fingers are never off the home row. You’re faster, better than before. You may, in fact, be a secret government project that brings test pilots back from the grave. Who knows. These ‘boards usually have 61 keys or so. There’s a middle ground between this and the TKL form factor that conforms to everything I’ve said above, except for the fact that the arrow keys are still there, shoehorned down into the corner of the alphanumeric block. These are typically called “67%” format.

40%: Now, we’re verging on the realm of the absurd, at least to my way of thinking. This format takes it as a mission to be as small as humanly possible. Even the normal number row has to go. Some common keys, like the question mark, have to use a function layer to be available. I should mention that all the key caps and spacing remain the same as on a full sized keyboard. The designers don’t actually shrink the size of the keys. There are typically only 47 or so keys on a keyboard of this type.

40% is an uncommon format, but you do see it around some. I haven’t tried one, but it sounds like there would be a big learning curve, and I can’t really see what the upside might be. My TKL keyboard is still pretty compact, at least for my needs. I do have a bluetooth keyboard that is roughly 60%, and it works fine. It isn’t mechanical, however, so I won’t spend a whole bunch of time on it. Likewise, I won’t linger on the oddball mini keyboards that use little keys, rubber tabs, and the like to make a keyboard wicked tiny. If you have to actually type on something like that, I’ll just say that I’m sorry.
There are a few other formats out there, but those are most of the ones that are available on more than one brand’s products. For most, the full sized or TKL layouts will serve to be as broad a choice as they require. With mechanical switch keyboards, one dimension that can’t really shrink very much is that of height off the desk surface. Mechanicals featuring the familiar switch types are almost always at least an inch tall. Most everything that manages to be space efficient in this dimension will be a membrane keyboard with a scissor switch above it. Some of these are okay, but many of them…kinda suck.

Next time, I’ll talk about key caps, including their interchangeability, material, and shape.

Cheers, and happy typing.


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