order of operands



Hi,

I've noticed that Maxima often changes the order of operands in sums that I enter. Is it 
possible to suppress this behavior, so that when I enter "a + b", I get "a + b" and not "b + a"?
And one more possibly related question: is there any way to disable automatic simplifications, 
so that "a/a" would remain "a/a" until I explicitly ask it to simplify to "1"?

Thanks in advance,
Mikhail Khoklov