I am interested into programming with different languages besides Ti-Basic (like Java, C, and Python) on my Ti-84 plus calculator. Does my calculator support this, and if not, are there any calculators on the market that would be able to do this? Thanks in advance!
(The idea is that when I don't have access to my computer at home, I could just pull out my pocket calculator and start programming and testing out some algorithms on the go that come in mind.) 
It doesn't have to be a calculator, just something cheap and programmable and something I can carry around in my hand.
You would need a compiler that will translate whatever language you're writing in (in the case of Java, an implementation of the JVM as well) to the assembly used by the calculator's CPU, it's probably not likely you will find an easy to use solution as calculators like the TI-84 are pretty archaic.
Multiple Language Programming on Ti-Calculator