i'm playing the game, Ultima Underworld 1, i noticed many poisonous traps around the level 3 and i have the rune to disarm it and the skill "trap" very powerful like my DEX value... but i can't detect the trap and so i can't disarm it. How can I detect a trap in this game? How can I disarm it? I'm trying to translate the game into my language, so i need to make the text lines appear on screen to make some experiments.

edit:
i'm trying with some traps inside a room in level 3, there is a puzzle with three buttons to open a door, the instructions are writed at the bottom of the wall behind one of the poisonous traps.