Yesterday, I alluded to something I'm calling thzspaczproblem with the FrogPad. As you might discern from the name, it has to do with the spacebar turning the "e " sequence into "z" when typing at speed.
The reason for this is that the FrogPad is a semi-chording keyboard. Actually, FrogPad uses a bunch of different paradigms to pack all the complexity of a PC-105 105-key keyboard into only 20 keys. Sometimes, I think the multiple paradigms cause some cognitive dissonance, making advanced usage harder to learn.
Normal keys: 15 letters, [Space] and [Enter] act like traditional keyboard keys; press and release to send the key, hold long enough to enter repeat mode and send the key rapidly.
Chording Keys: The rest of the letters are produced by "chording"; you press a modifier key "simultaneously" with another key to access a different meaning of the latter key. The [Space] ([Green]) and [Number] ([Orange]) keys function as chording modifiers. To make these easier to use, you get a bit of leeway--if you hit a chording modifier and another key at really chose to the same time, the keyboard helpfully treats them as a chorded keypress. This is essential to make chording work (you don't hit the keys at the same time, nor do you release them at the same time, and they may not ever be pressed at the same time).
"Dead" Keys: Dead keys, when pressed, do nothing, but cause the next key pressed to behave differently, then return function to normal. The FrogPad has the following dead keys: [Shift], [Ctrl], [Alt], and [Command]. These work a little differently than normal dead keys, because they in fact press and hold the associated modifier key until another key is pressed--this rarely matters. If the next key is also a dead modifier, both are held for the next keypress. Pressing one of these a second time will release it.
Hold Keys: The dead modifiers and the [Application] (aka Menu) key have an alternate combination which puts them in Hold (or Shift Lock for Shift) mode. Most are released by pressing the modifier again, except Shift, where you have to press Shift Lock again.
"Thzspaczproblem", of course, follows from the necessary implementation of leeway for chording, and the clever special status of [Space], under the thumb where it's easy to press, as both [Space], the most-pressed key, and [Green], the most-used modifier. Normal fast typing often involves not only moving to, but pressing, the next key while still releasing the previous key. Normally, keyboards can handle this, and this one can in most cases, but when the key combination is potentially a chord, it has to guess. Thus, your word-terminal primary letter and space turn into an alternate letter instead. This can also happen to [Number]/[Green], of course, but it's much rarer.
I'll reserve discussion of the (more minor) points of potential cognitive dissonance for a later post; typing one-handed is still rather draining physically and mentally.