Engineering

13.1 Symbulator

Roberto Perez-Franco's Symbulator site:

Here you can get Symbulator; a symbolic circuit simulation program and many other high quality applied mathematics and engineering programs.

13.2 Signal89

Lennart Isaksson's Digital Signal Processing Program Suite for the TI-89. This is a very impressive package of programs with MATLAB - like capabilities. Complete with instructions in PDF format. Find it at the Symbulator site.