These all require a Casio FX-9700 Calculator, although there's no reason why they shouldn't work on other models. Click each title to view a description of the program and the code. All files are text files typically 2kb in size.
Sean Tan also maintains a site dedicated to more modern Casio graphics calculators at http://www.casiokingdom.tk/.
Disclaimer: The code for the above programs is provided as-is: no responsibility for correctness or suitability of the code is taken whatsoever. If you do have a suggestion or bug fix, head to my contact details page to email me and I'll see what I can do.