TI Basic is one of the languages that can be used to program Texas Instruments programmable calculators. It is built in to the calculator, and thus doesn't require a computer, as I believe Z80 (or whichever chip is in your particular TI calculator) Assembly language programming does. It is very much like BASIC in its style and structure, and thus is quite simple to learn.

Anyway, I'm no TI or Basic guru, so I'll leave it to someone more knowledgeable to make a better overview-type writeup. Instead, I thought I'd share a couple of programs I wrote back in grade 12, so that others might make use of them. (Notes on notation and such are below.)



Quadratic Roots Formula

ClrHome
Prompt A
Prompt B
Prompt C
((-B)/(2A))+(sqrt(B2-4AC)/(2A))->P
((-B)/(2A))-(sqrt(B2-4AC)/(2A))->Q
Disp "X=",P,Q
The above program will solve an equation of the form Ax2 + Bx + C = 0 for x by the quadratic roots formula. It prompts for A, then B, then C, and spits out the answer.

Summation

Input "UPPER LIMIT=",N
Input "INITIAL VALUE=",K
Input "INCREMENT=",J
Input "FUNCTION OF X=",Str1
String>Equ(Str1,Y0)
0->A
For(I,K,N,J)
I->X
Y0+A->A
End
Disp A

This program will calculate the summation of some one-variable function (X must be the variable) entered by the user over a given interval, with a given increment.

Notes:
Instead of the square root symbol, I've used sqrt(. In the program, you should of course use the square root sign.
-> denotes the store character (the button marked STO> on the TI-83).
The functions used in the programs should be listed in the index of your manual; if you don't have one and don't know where to find a function or variable name you need, hit the Catalog function (2nd + 0 on a TI-83), and scroll down until you find it. If you need any help, /msg me. :)