I realized I could do this, and I thought it would be rather neat to have one, so I wouldn't have to dig out my ti-89 every time I wanted to see a graph.
It is nothing spectacular, but let me save you all the trouble
I commented fairly well. If you understand parametric equations you will have no problem understanding this.
Edit: This is version 2 of the NPC. It can now handle x!=t, as well as adding a few new easy things to manipulate.