I built a keyboard that fits exactly what I need

I really like the Corne layout. It's compact and symmetric, your fingers barely have to travel, and it's just comfortable.

But I work in simulation. A big part of my day is filling in parameters and tweaking values in software, which means typing a lot of numbers. Corne has no number row, so the digits live on another layer: hold the layer key, type, let go. One time it's just an extra key press. Over a day, it keeps breaking my rhythm. So I started wondering: could I keep the Corne layout and put the numbers right above my fingers?

That was the first version of MIX: the Corne layout with a number row on top.

The second problem was the mouse. The nicest thing about a split keyboard is keeping both hands on it. In reality, every time I needed to nudge the pointer, click into a text box or select a bit of text, my right hand had to leave the keys to find the mouse, then find its way back. It's not far, but it really breaks your train of thought.

So I decided to put a touchpad right on the right half.

The first version didn't get it right. I placed the touchpad too high, so my fingers had to stretch way up to reach it. It was awkward enough that sometimes I'd just grab the mouse anyway. That taught me something: a spot that looks reasonable on the drawing can feel completely different once you use it every day. I reworked the touchpad position so it's easier to reach, and that's when it finally clicked.

The roller was a pure accident. I came across this knurled metal roller part and my first thought was: that's so cool. Then I started wondering whether it could fit on my keyboard and give it something more to do. I tried putting it in, and it became part of MIX.

And that's how it went: it started as "I want a number row" and grew, one piece at a time, into what it is now.

I also added fold-out legs underneath, so each half can tent on its own.

Looking back, every change in MIX came from something that felt awkward when I was using my own keyboard. It won't be for everyone, but it's very much for people like me: lots of numbers to type, and no wish to keep taking my hands off the keys.

What do you think of the design? I hope you like MIX too.