I am trying to remap my n900 's keyboard , my intention is to add all function keys ,symbols , super , menu , page up ,page down , home , end , delete ,tab and escape keys to be usable from the keyboard .

I read the instructions at :
http://wiki.maemo.org/Remapping_keyboard

before attempting to add none existing keys , i thought i would try adding an already present symbol to the fourth level of another key and see how things work..

I tried to add question symbol to the comma key , so my thought was that 1st layer would be the comma , second would be equal (pressing alt+comma) , third would be semicolon (pressing shift+comma) , and fourth would be question (pressing ctrl+comma)

so editing /usr/share/X11/xkb/symbols/nokia_vndr/rx-51
under the xkb_symbols "english_base"
I changed the following line from :

key <AB08> { [comma,semicolon,equal,equal] };

to

key <AB08> { [comma,semicolon,equal,question] };

then saved the file and set the new keyboard settings ...

well... control+comma it writes a comma as if ctrl wasn't pressed,

so i went back to the file and reedited the line to :

key <AB08> { [comma,semicolon,question,equal] };

after saving these settings , pressing alt+comma does write question , but ctrl + comma doesn't write equal , still writes a comma.

so basically i can't get the fourth level to activate , If any one knows what I am doing wrong / what I should do please help me .

[edit] adding new symbols to the third level of other keys works as expected , so the problem is how to activate the fourth level .
I tried using the toggle ctrl-shift option but still nothing changed , also in the comment at the start of the file , layers 5-8 are mentioned , can some one explain how to get layer 4 to work (ctrl+key) , and where are layers 5-8 !

thanks in advance !

FOUR_LEVEL mappings work as of PR1.2 -- before they didn't.

To access the FOUR_LEVEL mappings, lock (by double-pressing) either one of the two modifier keys Fn or Shift, then single-press the other modifier plus the target key.

--denis

thanks alot for your reply , I did what you pointed out now , pressed shift twice , then pressed ctrl+comma , still prints a comma.. However pressing shift twice then alt+comma does print a question mark.
but how can i get ctrl+key to work ? is it possible at all to have ctrl as a modifier key ?

thanks !