Casio was among the first manufacturers to market a programmable calculator in the 1970s. As this was before the advent of the personal computer, these calculators were highly prized by scientists, engineers and techno-geeks. Casio still makes programmable calculators as of 2010, and they can be handy for solving a routine, complex formula when a computer is not available. Writing a program on a Casio takes patience and concentration.
Press the MODE key and the "5" key to enter the PROG mode.
Press the "1" key to select the NEW option. This displays a screen for entering a name for the program.
Enter up to 12 characters for the program name, and press the EXE key.
Press the number key that corresponds to the type of file mode you want for the program. The file mode determines where the program will be filed on the calculator when you want to retrieve it. File modes include COMP, BASE-N and Formula.
Input the program, using the "Return" key to create a new line. Use the "Program Commands" found in the user manual to program variable inputs and result outputs. Use the "Formula" keys on the calculator to define operations on the input variables.
Press the EXIT key when finished entering the program.
To run a formula, press the "2" key while in the PROG menu, then press the FILE key. Use the right and left arrow keys to switch between the "Prog" and the "Fmla" screens and select the program name. Press EXE to run the program.
It's best not to try to write a program until you are thoroughly familiar with using all the calculator's function keys. This procedure works for newer Casio programmable calculators as of 2010, but may not work for older models. Review the user documentation to verify the programming procedure for a specific model.