It is a PARALLEL positive keyboard with additional 10 common letters, the most commonly used.
These letters (Т,П,З,Н,У,С,Л,К,Р,Д) are placed instead of the upper numbers.
We did it pretty “mnemonically”
– the letter З (ze) stands for the number 3. Here the similarity is about 100%
– the letters Т and П are instead of the numbers 1 and 2 – in the number of vertical figures.
– and so on.
The left half of the parallel keyboard can give diagonal elements with one click (ie, А,И,Б,І,О,В,Я,М,Е, as right) if immediately followed by one of the above letters (Т,П,З,Н,У,С,Л,К,Р,Д).
But any letter can be typed using “normal” (for parallel positive keyboard) stereo effect.
Our experience shows that this option is optimal.