TI-83 should be fine. :)
"Permitted Calculators
You may use any four-function, scientific, or graphing calculator, unless it has features described in the Prohibited Calculators list. For models on the Calculators Permitted with Modification list, you will be required to modify some of the calculator's features.
Prohibited Calculators
These types of calculators are prohibited:
* Texas Instruments: all model numbers that begin with TI-89 and TI-92, and the TI–Nspire CAS—The TI–Nspire (non-CAS) is permitted.
* Hewlett-Packard: hp 48GII and all model numbers that begin with hp 40G, hp 49G, or hp 50G
* Casio: Algebra fx 2.0, ClassPad 300, and all model numbers that begin with CFX-9970G
* calculators with built-in computer algebra systems
* pocket organizers
* handheld or laptop computers
* electronic writing pads or pen-input devices—The Sharp EL 9600 is permitted.
* calculators built into cell phones or other electronic communication devices
* calculators with a typewriter keypad (keys in QWERTY format)—Calculators with letter keys not in QWERTY format are permitted."