I've yearned for an RPN calculator on the nspire so I can train myself in using it, so I created one in LUA.
In the default mode, it has 16 registers and has access to most common operations, and it also saves properly.
You can read more about what RPN is on Wikipedia. There's also a bit more about the app, as well as sample expressions in the readme.
If you want, you can copy and paste the script into other problems from both the calculator and the student software.




I'm pretty sure this is compatible with all nspires, including clickpads. If not, let me know.

TI put some SAT prep questions from The Princeton Review up for download for free. I've taken one of the tests already. The questions were fine, but I discovered that I was unable to check my answers after doing all the questions.
I could see the review being useful for when I have to take the SAT, but if I don't know the answers to the test prep, I can't learn from my mistakes.
Is there a way that I can force the document to be self-check without the teacher software?

I'm creating a simple tile-based game similar to Chip's Challenge in LUA, and I'm having a strange problem. I mainly test my game on the TI-Nspire CAS Student Software that came with the calculator, and my game works fine. However, when I transfer the program to my calculator and run it, a few bad things happen:

1. The level-area, composed of a solid background color with two object layers and the player, doesn't draw right. It only draws the player and the background.
2. When I attempt to move the player, the script crashes with an error in the collision detection functions saying that it's trying to compare my player's position to nil. What it should compare it to is the result of an expression that returns the object ID of an object at a position in the "level table" (where objects are stored) specified by a function argument.

I've figured this much out: the level loads right, because a function called in the level initiation function that scans the room for a certain number of objects works. I just don't know where to go after that. Is there any platform-specific difference that I'm missing that's stumping me?
I'd rather not share my source code unless necessary because it's very messy. If needed, just tell me.