The TI-83 series of graphing calculators is manufacture by Texas Instruments. The original TI-83 is itself an upgraded version of the TI-82. Released in 1996, it is one of the most used graphing calculators for students. In addition to the functions present on normal scientific calculators, the TI-83 includes many features, including function graphing, polar/parametric/sequence graphing modes, statistics, trigonometric, and algebraic functions. Although it does not include as many calculus functions, applications (for the TI-83 Plus -- see below) and programs can be downloaded from certain websites or written on the calculator.