Bdtyktl

I use a us-intl with "AltGr dead keys" layout and the option to switch Alt and Win key. Nice, but my AltGr does not work. The key I want to use for AltGr has keycode 134 (found out using xev). So I create a .Xmodmap file:

keycode 134 = ISO_Level3_Shift Multi_key ISO_Level3_Shift Multi_key

than I execute "xmodmap .Xmodmap". When I now show my modifier, I get:

> xmodmap

xmodmap:  up to 4 keys per modifier, (keycodes in parentheses):



shift       Shift_L (0x32),  Shift_R (0x3e)

lock      

control     Control_L (0x25),  Control_R (0x69)

mod1        Alt_L (0x85),  Meta_L (0xcd)

mod2        Num_Lock (0x4d)

mod3      

mod4        Super_L (0x40),  Super_R (0x6c),  Super_L (0xce),  Hyper_L (0xcf)

mod5        ISO_Level3_Shift (0x5c),  ISO_Level3_Shift (0x86),  Mode_switch (0xcb)

But ... pressing AltGr (the key with code 134=0x86) + q does not give the expected result - which would be "a-umlaut".
It should! xmodmap -pke contains this line:

keycode  24 = q Q q Q adiaeresis Adiaeresis adiaeresi

So what is wrong and what can I do?

According to the Xmodmap Manual, when you want to swap or change modifier keys you need to remove & clear their ties to their original keycodes and modifier groups. Then after assigning them to a new keycode you must also assign them to a new, unique group.

It looks like (this seem to be fairly common due to manufacturer configs) modifier group 5 has been assigned two different modifiers [Level3_shift] & [Mode_switch]! In effect, pressing one of them, activates/sends them both to the system. Each of them is designed to provide access to a unique layer/level of the keyboard, as well as an additional unique layer/level when pressed together.
[Mode_switch] is apparently synonymous with [AltGr] providing access to layer 2- the second set of [q] & [Q] in your example, [ISO_Level3_shift] provides access to level three- the [ä] & [Ä] in your example- but you can't type either of those keys without typing both until you change your .xmodmap file. And your second "adiaeresi" (sic.) is missing the final [s] so it wouldn't produce any character.

I know this rather confusing and convoluted for no apparent reason, plus this thread is old. But hopefully someone will find my explanation useful at some point!