hmm... on my device is sudo su working. But it's ok if you use
instead. It is exactly the same command.
So, become root with sudo gainroot and then go ahead.

note: do not uninstall rootsh or you can't become root.

Sadly you can't assign different characters for any fourth level combination because it's supposed to work as a third level + shift to get an uppercase variation of the third level character.

so i can't use capital letter with fn+?

I'm using capital letters of the fourth level, bout just the letters. The accents are not working
Let's take an example to explain you:
This is:
a = just press the key
A = shift + a
b = fn + a
B = shift + fn + a
NOTE: you can't type B if you keep shift and fn pressed when you are typing the a key.
You have to lock one of the two keys: so, for example, double press shift and type fn + a. Also locking fn and shift is ok. Locking fn and pressing shift + a is not always working.

Hi. This doesn't seem to work for me...

In my /usr/share/X11/xkb/symbols/nokia_vndr/rx-51 file I have in the

xkb_symbols "english_base"

part,

I put this in place then ran the setxkbmap command.

But using your instructions (shift, shift (shift lock notification appears) fn + h ) I still get a normal parenleft.

I checked, and changing the remaining parenleft to braceleft does give me a '{' (after setxkbmap) with just fn+h.

Any idea what the cause is? I wonder if it's due to localisation, but I can't see a specific setting in the file that might affect this. I think others have had trouble finding the "fourth level" too..

What language region have you set?

I have device language and regional settings both set to "English (UK)" in the setup menu, but I don't know where this might be seen in config files.

as I wrote
and
as Mitja wrote.
This means that the fourth level character (the B in my example -> shift + fn + a) can only be a letter, not a symbol like the '}'. This is not the uppercase variation of the third level character, which is '{'.
Because:
shift of 'h' = 'H'
but shift of '{' = '{' - you cannot say that '}' is a capital '{'
So fourth level: only capital third level's letters.
If you look carefully the other keys are set like this:
Fourts and lhird levels are the same character, because it's a symbol.

Hope it helps.

Meh, sorry, didn't understand at all!

I see what you're saying now.. I was misled by this comment in the file:

"// Shift switches between current level and level+1"

thinking "oh, well I should be able to get 4th character.."

I've really been puzzled about this for over a month, so although it's disappointing not to be able to further map the kb, it's very satisfying to finally know what's going on.. Thanks!

Has anyone any idea of what is going on with Multi_key interpretation? As an exercise I tried modifying the Q key to be Multi_key. My idea was that to steal that key and then to type q you would e.g. have to type qk or qK for capital q. You would then be able to use combinations like qo for å or whatever other characters your fancy.

But I couldn't get Multi_key to work in Xephyr. The key is just silently ignored. I know the mapping works because if I in the same Xephyr session run a program from outside of maemo, e.g. "xterm -display :2" then the modifier key works.

DO NOT FOLLOW MY STEPS FOR NOW. YOUR PHONE WILL TURN INTO A BRICK AT NEXT REBOOT. I HAVE BRICKED 5 N900's SO FAR IN 5 ATTEMPTS, THAT'S A SUCCESSFUL BRICKING PERCENTAGE OF 100%. I'M INVESTIGATING THE PROBLEM WHICH SEEMS TO BE RELATED TO CHANGES MADE IN FIRMWARE FROM WEEK 51.

Note:
My icelandic keyboard disappeared when I upgraded to firmware from week 51. So I had to recreate it. I don´t know if something changed in the rx-51 file in the update, but I am assuming so. So I say that this is only for people who have applied the 1.1 firmware update from week 51.

If you´d like a keyboard for yourself that works and allows you to switch into your custom keyboard and back into the english one you can follow my instructions and modify as necessary. As the russian keyboard is the only one that allows ctrl+space to shift languages I have sacrificed it as a basis for my Icelandic keyboard.

I have all 4 arrows working in the english keyboard and 2 arrows working + special keys in the icelandic one. This makes the arrows work in a similar way in the icelandic one as if you select other european languages than english with ctrl+shift, but behave in the english 4 arrow way when you have that selected.

The "english base" is disabled in rx-51 for this keyboard, because the "english base" tells the N900 to always treat the arrow keys as 4 button arrows. With my modified keyboard I want to be able to change in and out of that so that is not fitting

Quirks:

1. I cannot have "left arrow" and "up arrow" on the "down arrow" button. I can´t get it to work, like it does on the european keyboards, so the "down arrow" gives left when pushed and "up" when fn+down is used. My current setting could of course be changed to "down" and "up"
2. I can´t have "right arrow" and "down" on the "right arrow" button because of the limitation above. I can´t get it to work, but you could change my current settings to have "left" and "right" on this button.
3. Switching between icelandic and english keyboard is as simple as pushing ctrl and space at the same time

Items I´d like assistance with, or I consider not complete:
I´d like to modify the character map for special characters, that appear when you press fn+ctrl. I do not have ability to run the linux application for vkb files that is outlined here:
http://wiki.maemo.org/Special_characters_view

If you could run the vkb compiler to create a vkb for "russian" as detailed in the attached "icelandic-vkb.txt" I would truly appreciate it. If you could then reply and attach the new file I´d be most thankful.

How to install the keyboard detailed below:
Prerequisites: You will have to have installed rootsh from Maemo-Extras. If you do not have it installed, or have not enabled Maemo-Extras please see: http://wiki.maemo.org/Extras#

Lower and uppercase matters in Linux/Maemo so you have to do exactly as specified!

1. Save down the rx-51.zip file attached to this entry onto a location on your computer where you can easily access it.
2. Unzip the file so that you have the file rx-51 in location on your computer you can easily access. (Notice the file does not have a filename ending)
3. Connect your N900 in Mass Storage Mode. Navigate to the tmp folder on the N900 itself. Copy the rx-51 file from your computer into this folder on the N900.
4. Disconnect your N900 from the computer.
5. Go into the program X-Terminal on your N900 (it is in Applications > More)
6. write sudo gainroot into the X-terminal window and hit enter
7. write cd /home/user/MyDocs/tmp and hit enter
   
   Now you are in the directory where you just copied the rx-51 file. Now you need to copy the rx-51 file to where the N900 uses it.
   
8. Write cp rx-51 -i /usr/share/X11/xkb/symbols/nokia_vndr and hit enter
9. The N900 should now ask you whether you wish to overwrite the old rx-51. It should be safe to do, so you can say yes. If you feel unsure about that then you can write:
   cd /usr/share/X11/xkb/symbols/nokia_vndr to get into the directory where the original rx-51 is and copy it to for example /home/user/MyDocs/ (one level up from where you placed the new one) by writing cp rx-51 /home/user/MyDocs and hit enter before you copy your new rx-51 file into the nokia_vndr folder.
10. Congratulations, you now have installed the new Icelandic keyboard to use alongside the english one.
11. To select the keyboard go into the Application Menu and select Settings. Now browse to Text Input and therein go to Hardware keyboard layout. Select the strange word looking like "Pyccknn" at the bottom of the list. That word is "Russian" in the russian cyrillic alphabet.
12. Click save.
13. The N900 icelandic keyboard has now been applied to your hardware keyboard. Enjoy typing away!

Icelandic keyboard follows: - Remember that I sacrificed the Russian keyboard, hence it says that levels 5-8 are russian and that the xkb symbol is "ru"

// Levels 5-8 are Russian, levels 1-4 US English, for shortcut reasons.

partial alphanumeric_keys
xkb_symbols "ru" {
// include "nokia_vndr/rx-51(english_base)"
include "nokia_vndr/rx-51(common_keys)"
include "nokia_vndr/rx-51(modifiers)"

name[Group1] = "Icelandic";

key.type[Group1] = "EIGHT_LEVEL_SEMIALPHABETIC";

// 1. row
key <AD01> { [ q, Q, 1, 1, q, Q, 1, 1 ] };
key <AD02> { [ w, W, 2, 2, w, W, 2, 2 ] };
key <AD03> { [ e, E, 3, 3, e, E, 3, 3 ] };
key <AD04> { [ r, R, 4, 4, r, R, 4, 4 ] };
key <AD05> { [ t, T, 5, 5, t, T, 5, 5 ] };
key <AD06> { [ y, Y, 6, 6, y, Y, 6, 6 ] };
key <AD07> { [ u, U, 7, 7, u, U, 7, 7 ] };
key <AD08> { [ i, I, 8, 8, i, I, 8, 8 ] };
key <AD09> { [ o, O, 9, 9, o, O, 9, 9 ] };
key <AD10> { [ p, P, 0, 0, p, P, 0, 0 ] };
key <AB08> { [ comma, semicolon, equal, equal, eth, Eth, equal, equal ] };

// 2. row
key <AC01> { [ a, A, asterisk, asterisk, a, A, asterisk, asterisk ] };
key <AC02> { [ s, S, plus, plus, s, S, plus, plus ] };
key <AC03> { [ d, D, numbersign, numbersign, d, D, numbersign, numbersign ] };
key <AC04> { [ f, F, minus, minus, f, F, minus, minus ] };
key <AC05> { [ g, G, underscore, underscore, g, G, underscore, underscore ] };
key <AC06> { [ h, H, parenleft, parenleft, h, H, parenleft, parenleft ] };
key <AC07> { [ j, J, parenright, parenright, j, J, parenright, parenright ] };
key <AC08> { [ k, K, ampersand, ampersand, k, K, period, period ] };
key <AC09> { [ l, L, exlam, exclam, l, L, comma, comma ] };
key <AB09> { [ period, colon, question, question, dead_acute, colon, question, question ] };
key <UP> { [ Up, Up, dead_diaeresis, dead_diaeresis, ae, AE, dead_diaeresis, dead_diaeresis ] };

// 3. row
key <AB01> { [ z, Z, pound, pound, z, Z, pound, pound ] };
key <AB02> { [ x, X, dollar, dollar, x, X, dollar, dollar ] };
key <AB03> { [ c, C, EuroSign, EuroSign, c, C, EuroSign, EuroSign ] };
key <AB04> { [ v, V, slash, slash, v, V, slash, slash ] };
key <AB05> { [ b, B, backslash, backslash, b, B, backslash, backslash ] };
key <AB06> { [ n, N, quotedbl, quotedbl, n, N, quotedbl, quotedbl ] };
key <AB07> { [ m, M, apostrophe, apostrophe, m, M, apostrophe, apostrophe ] };
key <SPCE> { [ space, space, at, at, space, space, at, at ] };
key <LEFT> { [ Left, Left, aring, Aring, thorn, Thorn, aring, aring ] };
key <DOWN> { [ Down, Down, Up, Up, Down, Down, Up, Up ] };
key <RGHT> { [ Right, Right, Left, Left, Right, Right, Left, Left ] };
};

Icelandic keyboard illustrated:

I think I am basically done with the instructions now. If you can assist me with the virtual character map I´d appreciate it.

Also if you have recommendations for changing this further for the better, or the instructions, please let me know