A tale of two Corne: one month with split keyboards

My split keyboard journey started with two Corne keyboards and a Sofle all purchased over a period of two months. The Sofle is from Ergomech and is a Bluetooth enabled.  I use it as a wired work keyboard.  The two Corne keyboards are from YMDK, purchased through Amazon. One is an MX, the other is an MX low profile.  Here, I talk about the two Cornes. I will look at (1) Buying from YMDK on Amazon, (2) use of the two keyboards, (3) the keymap journey.

I bought the keyboards from YMDK on Amazon.com. YMDK markets pre-soldiered, hot-swappable,wired and wireless  (2..4GHz dongle) Corne 4.1 keyboards with 3D printed enclosed case with 46 keys  (3x6 +5). Also a wireless Sofle.  I wanted wired only to make my first steps into the split keyboards with fewer complications, in particular the wireless versions are powered by replacable button cell batteries, that I did not want to deal with. I immediately flashed both keyboards with 4.1 Vial versions of the Corne firmware and that had no problems.

I have one keyboard with MX Akko Dracula linear switches (35 g weight) and XDA profile PBT keycaps, and one low profile with kaith Deep Sea Whale Low Profile choc v2 (silent tactile).  The first keyboard I ordered was a refurbished MX switches. The right side did not work, and I suspect this is because Amazon refurbished items usually are returns, and the prior owner probably shorted the keyboard. A couple back and forths with YMDK customer service (there is a link on Amazon to them, and it is not too hard to get the YMDK customer service email address.) and we decided to return it through Amazon and I ordered a new one. The Low profile keyboard was not a problem. The website make it clear that it could take either Kaith 1333 (v1) or 1353  (v2) switches. So I got 1353 switches and used Wormier Low profile (skyline) key caps.  So, with Amazon return policies, I found buying from YMDK and working with their customer service reasonably good, although I am leary about any complications like wireless.

For using the keyboards, I use them with my own laptop and I have one at a standing desk that I use for both my work and personal laptop (I take a standing session and connect my laptop to a docking adapter). And I also bring the low profile Corne with me when I go in to the office (my acrylic sandwich Sofle looks a little fragile with its openings and the suspended acrylic oled screen cover). I like the low profile version. With the 3D printed case and low profile keys and switches, it feels relatively durable and no big failure points like catching on something. I warp up the halves in a bandana and put it with the cables into a lined bag and that seems to work well. I'm not sure I would like the low profile keyboard as my only keyboard, it feels tough because I'm always bottoming out compared to my MX Sofle. But as a secondary keyboard to provide variety I think it does well. And it does get attention when I take it around :-)

With the Akko Dracula switches, I think the light switches don't work for me. I am constantly having accidental key presses with mod-tap keys that I don't with the silent tactile keys with 45g weights. I think I'm going to put that keyboard aside until I feel like getting new switches for it.

The keymap journey is an ongoing one. I think I'm at a point that I only make small changes a few days apart.  Some big choices along the way in roughly the order I settled on them.

• QWERTY- I'm staying with the QWERTY layout. I know it well, and I am not so fast a typist that any keymap optimization can make any meaningful difference.
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• Numbers. I started with numbers being a top row of a layer. Eventually I realized that when I need numbers, I need several, so I switched to making a numeric keypad with arithmetic symbols on one side, then the other symbols on the other side of the layer.
• Symbols. There are seven'ish pairs that need to be taken care of. I touch type, so I wanted the pairs that are usually on the same key together.  So these are:  `~, -_, =+, [], {}, '", \|.  The quotes get taken care of by moving enter to the thumb cluster, so quotes stay in place. =+ and -_ I put with the numeric keypad. So I had two rows of the symbol layer were the []\'` on one row and the shifted version of those keys {}|"~ were in the row below that.  I put the brackets on the outside (left row) because I ended up putting all the brackets on combos, so I still have them on this layer, but on the edge.  And since I program in R, I put the ` and ~ closer to the index finger.  The top row of the symbol layer I put logical operator symbols:  <>&|!, (less than, greater than, and, or, not).  Making two columns of all the bracket keys (except parens) and keeping them in an order I would be able to remember.
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• Navigation. The top row of the navigation layer are the symbols that are the shifted number row.  For the remaining two rows, the right side is navigation, left side mouse control. Right side is centered on hjkl, because I use VIM and my fingers already know those keys.  Below those are horizontal keys, beginning of line, previous word, next word, end of line. I put page up and page down on the two keys to the right of those. On the far right I have beginning and end of document, but I don't think I use those that much. The mouse cluster is xdcv.  Then f,s are the click buttons, gb are scroll up and down.  za are scroll left and right.  I use these a surprising amount of the time (especially to help recover after accidental mod presses)
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• Adjust layer:  Left half is for controlling the keyboard (lighting), right half is media controls.  I have volume mute, down, using hjk, media back, play/pause, next anm,  l; are screen brightness.  ./ are zoom out/in.  I never really learned to use the keys because these were always on the function row and every keyboard had them in a different place. Now that I got to put them where I wanted, I use them a surprising amount.
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• Screen navigation.  I had window management (switch windows, move windows) on the thumb cluster. I figured if I was in this layer I did not need space, enter, backspace/delete. I knew these keys, but they were awkward on a normal keyboard
• Programming key combos.  I made combos for the bracket symbols ()<>{}{} with left on the left side and right bracket on the right. I tend to use these instead of the normal typewriter layout.  I have additional combos for : <- |> # for R programming (the I also have combos for open file and the command palette in Visual Studio Code.,
• Mod-tap and layer-tap. I have an extra layer tap keys on g and h, which I use to mirror my layer keys so each layer is accessible from each side of the keyboard. For example, the number pad, I can either use it single handed with the thumb holding the layer key, or use the index finger on the other side. I usually use it one handed if I only need one key on the number pad, opposite hand if I need more. I let my fingers decide. I also have (from outside in) home row mods of layer, shift, control, alt, gui. But I took out the gui modtap as I was doing too many accidental mod presses, especially with the Akko Dracula switches. (I think the other keys are not as noticable because they have momentary effects, but GUI and menu lead to something happenning.)
• Thumb clusters, I have ended up with the thumb cluster being Insert(held Ctrl), Enter (held GUI), raise layer (navigation), lower layer (numpad/symbol), space, backspace (held Alt). I realized that the menu key was also right click on the mouse (and the key on the mouse layer works), 

Some other decisions along the way

• Delete/Backspace. I first left backpace next to P and delete key in the thumb cluster, but I repeated used delte when I meant backspace, so I moved backspace to the thumb cluster and had delete in the corner.  It makes for the same Ctrl-Alt-Delete chord that I'm used to.
• Escape and tab. I started with escape in the corner, but my fingers always wanted tab to be next to Q. So Tab went into the corner and Escape went where CAPS LOCK usually is. I don't use CAPS LOCK much,  so I made a combo with both space keys as something easy to remember if I ever want it.
• Numpad. I started with the  numbers on the top row of a layer, but they were always awkward, just like they are normally. Then I realized they could be a numpad, with room for arithmetic keys around them. I also tried both left and right sides, and ended up with the right side. Because - and _ are used so much, I had those under the index finger and =+ went to the other side of the numpad.
• Shift and Ctrl/Alt keys. I tried out putting Shift in the thumb cluster and Ctrl, Alt in the corners where shift usually was, but changing that muscle memory was too hard.
• Space and Enter. I tried space on the left first, then saw I was making too many errors so I switched them.

Observations from use.

• I don't miss the number row. The only time I notice it is when typing passwords or other things like phone numbers where muscle memory knew where the numbers are, but I'm creating a new set of muscle memory.  And the symbol keys always needed a layer key (Shift).
• I use the media, zoom, and window management keys all the time. I never used them on a regular keyboard because I could not remember where every keyboards keep them and they were odd key combinations (odd to me). So these mean I am using the mouse a lot less.
• After one month, using a regular keyboard feels uncomfortable because it felt cramped and flat (I have a variety of tenting solutions) I don't remember it being much more comfortable when I started using split keyboards, but that is probably because of dealing with all the changes in geometry.
• I noticed that I only use the sixth column on the base layer with Tab-Escape-Shift and Delete-<'>-Shift.  So I am only six combos away from switching.to a 5X3 Corne (must resist . . .)

Setting up a keymap for a Corne split keyboard to be used for data analytics

Continuing my dive into the rabbit hole known as split keyboards, I got a Corne keyboard from YMDK on Amazon.com.  A Corne is an open source keyboard (circuit board and source code are freely available. The original creator is not in the keyboard building and selling business so he lets others improve his design and sell them) It is a 3 row X 6 column + 3 (thumb row) key per side board column staggered board. The goal here is comfort from being able to independently place the halves of the keyboard under my fingers and reduce the need to twist my wrists. (i.e. reduce repetitive strain injury)

The trick with this keyboard is what to do with they symbol and control modifiers. Also known as the keymap. The answer is creating layers, such as the shift layer used for capital letters and the symbols under the number keys. So I have a symbol/navigation layer and a number/mouse control layer.

There are a few general principles I had in making the keyboard.

1. The baseline is the standard QWERTY keyboard. I spent a lifetime building up my muscle memory and I'm not going to throw it away.
2. I wanted to try a numpad on the right side that should also be associated with common math symbols.
3. I wanted VI type navigation keys  (i.e. h, j, k, l correspond to left, down, up, right)
4. Keep the symbols associated with shifted number keys on the top row, in order
5. For symbols that did not make the base layer or the math layer, keep the symbol and the shifted symbol together (shifted symbol below the main one)y
6. As I use it and make mistakes, move characters to the key my fingers wanted them to be.

So, the base layer is as much of the QWERTY layout as could fit.  The left column had tab above escape above shift. I started out with the escape in the corner and tab under it, but clearly my pinky wanted the tab to be next to Q. For the right column, I started out with the backspace next to P and Delete under my thumb, but a bit of use led me to switch them.  The left thumb keys had insert, enter, and lower layer (symbols and navigation), with the insert key doubling as Control when held down (also known as mod-tap). The Enter key doubled as Alt when held. The right thumb keys were raise layer (numpad, math symbols, and mouse control), space (Control when held) and backspace (alt when held). I also set up home row mods, where both hands the home row keys doubled as shift, control, alt, Command when held.  

The lower layer was for symbols and navigation.  The top row had the symbols that would normally be on the shifted number keys.  The left side had the keys that were displaced from the base layer: []{}\|`~.  The right side had the VI arrow keys on h, j, k, l. The row below those where navigation within the row: beginning of row, previous word, next word, end of row. The column to the right had page up and page down. The last column on the right had top and bottom of document (or cell for Jupyter notebooks)

The raise layer was mouse controls, numpad, and math symbols. Left side had mouse controls (left, right, up, down, clicks, scroll) and math logic symbols &|!<>.  Right side was a numpad, with -+/*_= around the numbers.  

The third or adjust layer were to control the keyboard or computer.  Left side was the keyboard, specifically lighting.  Right side were media controls, screen brightness, and screen zoom.

What really made this work was the use of combos.  I made combos (two key combinations) for the bracket type symbols which were mirrored on the left and right sides. This covered <>, (), [], {}.  In the inside columns, I made combos for :, <-, |>, # which are used in R.

Actually, this was a major modification. My initial layout had the numbers along the top row on the raise layer. But while I don't use numbers that much, when I need them I need many of them, and a numpad is less awkward.  I think.  I will know after much more use.

And here are my keyboards.  I have two Corne's, one MX with Akko Dracula (low weight linear) and XDA profile keycaps and a low profile with Kaith low profile silent tactile with low profile MX keycaps.  And a Sofle with Oetemu silent tactile switches and XDA keycaps. The Keychron K12 with Cherry Reds and OEM profile keys is what I was using before as a reference.  The Sofle is used with my work computer (having a number row is useful for making passwords smoother). The low profile Corne is packed in a bandana and a bag for travel. The MX Corne is used for my personal/non-work laptop. Since I got my first Corne in late August, this represents a big dive into the rabbit hole of split keyboards. 

For tenting, the Sofle has M5 bolts that came with it from Ergomech, the low profile Corne is using Steepy laptop risers which is what I take when out and about.  And the MX Corne is on Cooper Cases MagSafe stands.