That's fascinating! If it's short for Mc and Mac names, does the accent go on the second syllable, as in "Mac-CAH"?

In America they sometimes call MacDonald's "Mac's". I believe I've seen movies in which men call other men whose surname begins with Mac "Mac", too. But not if their name begins with "Mc". This leads me to think a lot of people here say "MacDonald" or "MacBride", etc. with a strong pronunciation of the first syllable, like "MACK-BRIDE". I tend to say it as if it were the same as "Mc" names.