TBF-RnD is an open source project that currently focuses on input mechanisms. For an introduction on why this might be interesting to you, check out this post. We’re doing experiments like a prototype for an easy to learn chorded input mechanism.

A small “Plain Old Keyboard”

Early work by Troy Fletcher

Obviously a lot of clever people have thought about how to make keyboards better. One of the most obvious candidates for attributes that can be optimized on an input device is naturally its size. Above you’ll find a 40% keyboard.

Note that the keymap doesn’t have the row of numbers that you’ll probably find on your keyboard. Also there are no arrow keys. At first glance, it seems that this would only harm productivity, and still some people swear by it.

VIM-style movement and Fitt’s law

Vim users will be familiar with the concept of using the keys h,j,k & l for navigation instead of using the arrow keys. This is a historical artifact and may not be due to speed related reasons. Still a lot of programmers swear by using these keys for navigation. Why is this? Well, by having the navigation keys closer to the home row, you don’t have to move your hands as much.

Reducing unnecessary movement is something that is of a great interest for me. I’m particularly interested in finding out how well a setup using a “FPS-stance” would fare, i.e. typing only with the left hand and using the mouse for secondary actions. You can read more on that in this post.

Fitt’s law: the time required to rapidly move to a target area is a function of the ratio between the distance to the target and the width of the target.

It’s sort of obvious to figure out that the less we have to move our hand from the home row to the arrow keys, the more time we save. There is however a more formalized way to look at this in the field of user interface design.

With a 40% keyboard, we have to move the fingers less as well. No more than one key has to be travelled to find any other key. Fitt’s law states that if we have to move the finger, the size of what is to be hit has to be increased, or we’ll suffer an increased error rate.

Programmable keyboard for further functions

Creating your own keyboard from a kit and using an open source firmware buys you a lot when it comes to customizability. For example, you can have different functions on the same key depending on how you press it. The same key could be used for Escape and Ctrl for example.

R.S.I Repetitive Strain Injury

Split keyboard design by Troy Fletcher

One of the advantages with a small keyboard layout is that if you only have to move the fingers, you can keep your wrists in static positions. This would at least in theory be advantageous for people suffering or who are at risk for R.S.I.

Split keyboard layout designs have been used to mitigate these effects. The split design is more easy on the wrist and conforms to a more natural way of placing your hands.

How does it work?

So a 40% doesn’t have very many keys – how can it possibly be usable? Well the answer is the following: By using layers activated by modifiers, similar to how shift, alt or function keys work, the missing keys are added. Theoretically this is sort of adding an extra component to the input, so it can be thought of as a subset of chorded typing. Only adding one key however makes it easier to figure out which keys are to be interpreted as a single input signal.

Example keymap for a 40% layout

Get in touch and get updates

If you are interested in this blog please enter your contact details above and we can get in touch with you. Maybe you have some ideas of your own, feel like helping out with code or maybe just have a chat with cool people!


Whereas a computer programmer might see benefits from using a 40%-keyboard and an enthusiast might get hours of fun out of tinkering with the electronics, I do not believe that it’ll reach mainstream adaptation. Still I find that we can draw interesting conclusions from the concept.

First of all, the reduced distances will increase speed, something that becomes especially interesting if we go even further and reduce the numbers to – say – 10 keys. This means that for example, a gamepad configured to use a clever scheme, could tap into higher typing speeds by totally eliminating finger movement between buttons.

If it turns out that 40% keyboards can reduce Repetitive Strain Injury or R.S.I. we can try to construct the input methods of the future with these lessons in mind.

Support the effort

All of this is done on an ideal open source basis. To keep it that way your support is very needed. Please get in touch if you have ideas, share with people that might and check out patreon below!

References and further reading

The images in this post is of the designs of Troy Fletcher, who reached out to me earlier. I’ve discussed the matter with him and his web site is a great source of information on the subject. A brilliant man with a great deal of passion who also has a lot of insights into other things. If you also have ideas on this subject or believe that I am totally wrong, don’t hesitate to write a comment below or fill in our contact form!

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      1. that frog, which was once a harmless meme, has become a white supremacy symbol. it may be sad that your keycap is a victim of social change, but most people recognize it as a symbol adopted by neo-nazis

        the same argument could be made for swastikas, which were also once a symbol of different meaning

          1. I understand this is your website and it’s your prerogative to “moderate” comments to fit your narrative – even if they’re respectful and productive. If you hate immigrants, people of color, or human rights, you’re allowed. If that is the case, then a fitting response to the “what’s with the frog?” might be something like, “I’m a member of the alt-right and this frog brings me comfort.” This way, your intentions are clear.

            If you stand against those ideals, say so! Something like “I know it’s used an alt-right symbol, but I just like the frog. I’m not part of that group and denounce its ideals. I sincerely just like the frog.”

            Either way, I hope you ponder internally (or better, externally in a blog post) about: why you stifle discourse on your platform, the meanings behind symbols, and the future you want for generations to come.

            Thanks for reading, I hope you find the courage to allow this post.

        1. This willingness a lot of people have to actively give away Pepe is ideological cowardice. Nazis win when they can just claim any symbol as their own. You can either deny the alt-right their ability to associate neutral things with their movement, or intentionally give in and lose.

          “Oh but they already stoooole it waaahhh.”

          I’m not saying that no cultural property has been pulled to one side or the other. The Babadook is solidly a gay icon now. But Pepe has a long history and plenty of present use as just a fucking meme. Using a Pepe meme or “kek” in 2020 is not a pledge of allegiance to Trump by a looong stretch (and certainly not a swastika equivalent, which is meme-levels of Godwin’s law).

          Pepe isn’t racist. Garfield isn’t racist. Kek isn’t racist. People are racist and they try to poison popular culture then steal it. Fight back, ignore them, do anything but spinelessly give into the appropriation out of fear and self-censorship. The more we divert the nazis and vote away their power, the sooner we don’t have to have this discussion.

    1. It’s not a nazi from you fool, your the kind of forteen year (at least mentally) old kid that destroy the society these days.

  1. The reason I didnt take a typing class in the 1980’s was because I figured everything would soon be voice activated anyway. WTF are we still doing with keyboards?!?

      1. that frog, which was once a harmless meme, has become a white supremacy symbol. it may be sad that your keycap is a victim of social change, but most people recognize it as a symbol adopted by neo-nazis

        the same argument could be made for swastikas, which were also once a symbol of different meaning

          1. heh heh I’m not a member of the alt-right I just love to use the imagery that’s widely associated with the alt-right heh heh

  2. The arrow keys are an interesting topic because it makes sense to have them grouped together and more or less directly mapped to their meaning (ex: right arrow on the right, up arrow above, …). My first experience with a different layout was with the Kinesis Advantage, which is a split keyboard with left/right arrows under the left hand and up/down under the right hand. It took a while but I appreciated that they were easily accessible without moving from the palm rest.

    Then I bought a OLKB Preonic. The default layout with arrow keys on the same line on the lowest row was painful to use because I had to move my hand two rows and one column, messing with my right hand placement everytime. I finally changed the keymap to put the arrow keys on the home row where my fingers are laying, on a layer activated by the right thumb. Now, I can use the arrows without moving my fingers, just by pressing with my thumb and that makes it so comfortable !

    (I pushed the documentation of the features on GitHub if you want to have a look:

  3. Have you considered the addition of foot pedals as an ancillary input device to provide modifiers? You could add at least two with simple switches, to provide 3 altered states. Add a more comfortable rocker switch with two on states each (and an off position) to get 8 modified states. Simple buttons could be mounted to achieve contact when the toes are raised, to facilitate normal resting position when not performing modifiers.

  4. I’m saddened by the fact that so many people felt the need to express their unrelated experiences and opinions on this user’s blog, about a cartoon frog none the less.

    Just because you may perceive an object, image, person, or symbol a certain way does not mean that everyone else does.

    The comment section was likely intended to further discuss the topic at hand, rather than people to feign outrage and stir trouble. Anyways, back to our topic at hand.

    Thanks for bringing more awareness to the 40% Keyboard layout! Our modern 40% keyboards are much like Vim, utilizing many layers and possible macros. The amount of customization you can incorporate into a 40% Keyboard when using open source firmware such as QMK is really amazing. People who are attracted to constantly tweaking or improving their productivity and tools will enjoy keyboards like these.

  5. These “this is alt-right” guys are just spammers or 4chan idiots. Alt-right frog” is not a thing. Never was. Only a complete idiot believes in that crap.
    About the 40% keyboards, I wonder if having layers won’t slow down real-world usage, making a 60% keyboard a better option.

    1. I guess the question is how a tradeoff between smaller distances versus less layers work.

      One thing that I thought about if it is making program specific hotkeys harder to reach / slower to access.

      And nobody mentions the VIM key…

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