There's one thing that calculators can do that powerful modern gadgets cannot: run on AAA batteries.
It doesn't even have to be something as old as TI-83, too. For example, Casio Prizm FX-50 has a color screen, and can be mounted over USB as a storage device. And in terms of hardware power, it's fast enough to run a NES emulator: https://github.com/tswilliamson/nesizm.
It doesn't even have to be something as old as TI-83, too. For example, Casio Prizm FX-50 has a color screen, and can be mounted over USB as a storage device. And in terms of hardware power, it's fast enough to run a NES emulator: https://github.com/tswilliamson/nesizm.
(For the curious, here's a dev wiki for this platform: https://prizm.cemetech.net/index.php/Prizm_Programming_Porta...)