In the Ultima 9 directory there is a file called 
default.kmp. When opened in a standard wordpad or 
other text editor you will find the following text line:

      [Cheat Commands]

> Simply add the following codes underneath it:

      alt+shift+l = toggle_avatar_fly
      alt+shift+i = toggle_avatar_invulnerable 

During game play the corresponding keys Alt-Shift-I 
and Alt-Shift-L will activate the cheat functions. 

by The Swordsman