As other commenters have pointed out, it's as much about limiting the capabilities of these devices as it is about anything else. Teachers don't want students

As other commenters have pointed out, it's as much about limiting the capabilities of these devices as it is about anything else. Teachers don't want students to have unlimited power to solve equations, etc. They want students to do some of these things manually, for learning purposes. You don't necessarily want your students using whatever top-of-the-line devices/software that can make some of the coursework utterly trivial. Is this solvable in software? Sure! Students could run tablets running approved calculator software, and teachers could disable/enable features at-will at test time. This would of course rely upon students running some sort of verified software/hardware combo. Has anybody solved this particular challenge yet? Not to my knowledge. I think they may need to think about this, if they want to unseat the TI (a worthy goal)