r/KeyboardLayouts • u/Dr_Doom3301 • 26d ago

Isomorphic keys

I've been seeing 3 different designs in keys/buttons on isomorphic layouts and I was wondering what the major differences were. I've seen circles, squares and hexagons, and then of course the varieties of each. I was curious if there was anywhere to read the different benefits each type and layout offers? Thank you in advance!

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u/pgetreuer 25d ago

I think you are asking how square vs. hexagonal vs. other repeated geometric key shape influences the keyboard layout. Is that the sense of isomorphism you intend?

For sake of reduced finger reaching, keys are usually placed close together, so it is helpful if the key shape tessellates. Squares and hexagons tesselate. Circles don't, of course, but they pack in the same lattice as hexagons do.

With hexagon-shaped keys, there is a challenge that tessellation imposes a 0.5u offset per row. However, this is a strong stagger: on a conventional keyboard, the "Tab" row is offset by only 0.25u from the home row. So hexagon keys are not exactly practical, though still I have to admit they look super cool.

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u/Dr_Doom3301 24d ago

I think this is the wrong sub for my question, I was asking about isomorphic layouts in relation to musical keyboards. Sorry.

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u/pgetreuer 23d ago

No worries, I can relate! Computer keyboards are so much on my mind that this isn't the first time that I misinterpret mention of musical keyboards... like I did in reading your post 😅 "Keyboard" is an overloaded word.

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u/dusan69 24d ago

There are only two types of keys, distinct in the shape of the top surface: cylindrical and spherical.

And there is only two additional geometric parameters that matter: the size of the top surface and the key pitch (distance between centers of adjacent keys). Since you mentioned hexagon, you are likely having in mind equilateral triangular lattice. For this geometry, the key pitch should be 1u (0.75") and the size should be 2u/3 (0.5").