ouf, i’m sure almost everybody knows that:
on an engl./us keyboard the tilde key corresponds to the 126th letter. you can check that under prefs. palette / utilities: the second slider. hit tilde - : and you see 126!
on a spanish keyboard same place 126 shows the letter ‘Ñ’ (go through all the letters if you want): that’s the tilde key!
nice to know to prevent from headaches