TI-89 Resource page for Mathematics 220:

In order to use these programs you need to copy them to a computer and use the TI link software and a cable to download them to your TI. Once someone you know has them on their TI you can easily copy them to your calculator using the wire that came with your TI-89.

A collection (created by N. Berger) of public domain programs suitable for Math 220:

ODE HTTP: here (save the file to your machine and then transfer to the TI-89)

Fourier Series HTTP: here (save the file to your machine and then transfer to the TI-89)

FTP site: here (Then use right mouse button to copy the file to a folder.)

A file describing the ODE programs (and bugs) is here

(these programs include Laplace transforms, inverse Laplace transforms, solutions of systems of ODE's, computation of Wronskian. The package will install in your TI-89 as the LAPLACE subdirectory. To run them use [2nd]+[Vari-Link]. Look in the LAPLACE directory. Find menu. Hit enter. Once "menu( "is on the command line add the ")". Hit enter. The custom menu should now be at the top of the screen. To get back the standard menu use [2nd]+[custom]. To use these programs again just use [2nd]+[custom]. )

General TI site for information on calculators: here

Site for public domain TI-89 mathematics software: here