If I plot Y=sin(95X) on my TI-84 plus silver edition with window settings Xmin=0, Xmax=2π, the graph looks exactly like the regular sine function Y=sin(X).

If you graph the same thing on a TI-84 plus CE calculator however, they do not look the same. Instead you have to make a graph of Y=sin(133X).

What are these calculators doing? What difference between the calculators does this reveal?