Hello all, I am a high school student, who will be taking Calculus I, I need to upgrade from my TI-84+SE so I am considering either the 89 or the Titanium. The only differences I know of are the memory and the processor speed. Are there any other differences? Which have you guys used and liked? I already ruled out HP, so don't bother trying to convince me!!!!! (I am a little resistant to change) I know I cannot use the calculator on the exams or anything, but it will be useful for the SATs and more... Any input is welcome. Thanks a lot.