bjoernvold.com

I am trying to use Special Characters with an US English Keyboard.
For Example for Æ is Alt+0198 , ñ is Alt+164 and Ñ is Alt+165

I am using KDE on Mandriva 2010.2

There is some that is not turned on? Used to work in the past.

Post that on the Mandriva forum and seems to be ignored.

some characters here

In 2011 kde, I looked in Systemsettings > Input Devices > Keyboard > Advanced
I'm not at all familiar with these functionalities, played around with check marks, nothing interesting.
I pressed the Defaults > Apply buttons, then tried the left Windows key instead of Alt with your combo, got the above.
Edit: the forum borks when I leave the characters in, which was Vietnamese for the first combo, 164 for the second, Vietnamese for the third.
We have Vietnamese installed for the second keyboard/locale/whatever it is, I'm not very practiced at this, and those look like Vietnamese.
fwiw

I use Gnome character map, and find it to be quite good. You may be able to help yourself by installing the fonts themselves that are supported (there are many; but if you don't have them installed, they won't show up in any special character combinations).

Did not thought about that K