Is it possible to type in macron (e.g. "ā") without using U.S. Extended Keyboard? I want to type in macron (e.g. ā) in my OS X, but after I searched for how to type in it, I got that I first must use U.S. Extended Keyboard as suggested in this article.

However, once I switch to U.S. Extended Keyboard, I cannot type in å any more with ⇧+a and a, because on U.S. Extended Keyboard, it provides you with the aforementioned macron letter. 

So is it possible to type in macron with normal English keyboard on OS X?
This is just a option without changing the default Keyboard.

In OS X, this can be accomplished by holding down the A briefly and a pop-up will appear.



Just select by clicking or typing the corresponding number.  In this case 8

ā ← Like that

The repeat delay can be set to prevent eeeeeeeeee from happening too quickly.