5) I found the way this thing works for PoketBook Touch Lux 5 (PB628). But it was a loooot of try and errors. I made my own keyboard layout (Bulgarian) and I will explain how it works so anyone can edit the keyboard the way they want. So the file has to be a simple text file in the form XY.kbd, as XY is the short language code. I made my own layout to be BL so that is does not conflict with the official one - BG, and thus you can have both in the same time. In the fist line it is again the same XY letters and then : and the Language that you want to be seen, I written mine in Bulgarian so that it differs from the one pre-filled in the book.
Next lines need to be
_@$%:;!?"()
`1234567890
qwertyuio
asdfghjkl
zxcvbnmp'
=+-~ .,*/
_@$%:;!?"()
`1234567890
QWERTYUIO
ASDFGHJKL
ZXCVBNMP'
=+-~ .,*/
--
Or some form of this, I did not find any difference changing these - so just left them as in the file I found.
After that is the keyboard itself.
You can have up to 4 screens. It goes normal, shifted, numbers and shifted numbers. I made mine to be 4 rows and as close to the original possible - so that it does not differ when changing the layouts.
Codes:
sh - shift key (⇧)
bs - key to delete the last letter (⌫)
ok - submit key (Enter) (⏎)
sp - space key (white space) ( )
lg - language change (switch the layout) (🌐
nu - numbers key (?123)
After any key you can have :3 (or any other number) and this is how much room you give that key. For PB628 this was NOT and exact thing and it did require a lot of tries to get it ok.
Actual values of key are separated with a space. And any key can have an alternative (if you hold the key down for 500ms) that you can type after the /
I hope this helps!