I started working on the original Katana nearly a year and a half ago. Back then the main goal was to make a mechanical version of the Microsoft Natural Ergonomic Keyboard 4000, with various improvements. While work on a splittable version, and even a tentable version continues, the project took a tangent when a friend offered to make me a wooden 60% case.
I kept returning to the symmetrical row stagger layout of the Katana to look for ways to squeeze it into a 60% case, I eventually settled on this layout:
There are a few things about this layout that make it effective, which aren't all that obvious at first. I'd like to go through a few of those here.
Symmetrical, row stagger - a more ergonomic layout
Back when I started designing the Katana, I acted on the premise that the right hand half of a traditional keyboard layout is nearly perfect, it was the left hand side that encouraged bad hand posture, and so that was what needed fixing. The Katana60 layout adopts the symmetrical row stagger 'solution' that defines all the Katana prototypes.
Whether this makes it 'ergonomic' or not, I can't say without testing. However it does encourage a better angle for the left hand, that is symmetrical to the right hand. That was the goal, after all. I believe this makes it a 'more' ergonomical layout when compared to boards with legacy layouts.
Compatible with ANSI keycap sets.
Making a new layout is easy enough, making one that doesn't require non-standard keys (which just increase costs) is challenging. This layout works with a standard ANSI set.
There is a PCB under development that will support a variety of other layouts, including alternative bottom rows (and potentially even ISO and international sets). More on that later.
Arrow key cluster.
It has become common in programmable keyboards to move the arrow keys to a function layer; where they are positioned on the home row and are accessible by shifting to that layer. I do that on all of my programmable boards.
But there are many times when you just need access to those arrow keys without holding down a function shift key - the number of 40% boards that still make room for arrow keys is evidence of that.
The layout includes the arrow keys in the middle, where they are equally easy to reach with either hand, and in those instances when you need to mouse while using the arrow keys, they're right there.
Split space bar.
It still surprises me how often a new PCB will make it to a group buy without a split space bar, why is that? The layout about is one option that works, but the PCB will support a variety of alternative bottom rows - each one of them will support a split space bar
If you made it this far, it's probably because you're interested in the Katana60 project. I hope to complete the PCB and run a group buy by the end of the year. Before that I'll write a detailed post for the community forums, where the supported layouts will be listed and the general interest will be guaged using an interest check form.
Early feedback suggests there is some confusion with the above layout images. The layout graphic represents the keys used. The firmware I'm using is as follows:
Some of you have also noted that the prototype in the main photo has a different layout; that's because the prototype uses aekii caps (Apple Extended Keyboard 2), which uses non-standard bottom row key sizes.
The PCB will support both bottom rows and more!