Custom XKB layouts for special keyboards
Makes the = button work correctly. The button normally sends Alt+KP_6+KP_1, which is great if you're on Windows, not so great on anything else. This layout maps the keypad's Alt to AltGr, AltGr+KP_6 to KP_Equal, and AltGr+KP_1 to nothing (VoidSymbol). Thus, pressing the = button on the keypad will actually produce a =.
Provides mappings for the alternate symbols on SP's Symbiosis keyset, accessed through AltGr/Right Alt. A few keys have a fourth symbol accessed via Shift+AltGr.
To use these, first take the xkbmap file in the folder of the desired keyboard and append it to the end of your /usr/share/X11/xkb/symbols/us_sym. Make a backup of the file just in case.
First, test the layout by doing setxkbmap -device n -layout us -variant (sym|toprenumpad), where n is the device ID you want to apply the layout to as shown in xinput. Make sure the layout works as expected. This is not permanent, so assuming everything worked, you'll want to put it in your Xorg conf (see below).
Review the contents of the xorg file, and selectively add the contents to your xorg.conf or xorg.conf.d. Restart your X server to see the changes and ensure everything is working fine.
There probably is, xkb isn't exactly the pinnacle of documentation. Feel free to let me know if there's a cleaner way of doing something.