Mem Menu (User Defined buttons)

The calculator allows the user to define functions and constants and assign them to user defined buttons under the Mem menu. These are stored off to permanent memory so they will be available the next time the calculator is run. These constants and functions can then be accessed using buttons in the Mem menu, or they may be accessed by typing the button name on the keyboard.

Note: If the calculator needs to be reinstalled for any reason (such as an unrecoverable hang), all user defined buttons will be lost. See the Important Notes section on how to prevent possible loss of work by using the Save function in the main menu.

Required Stack Entries to Store a User Defined Button

To save off a user defined button, the stack must contain either one or two entries at the top of the stack as follows:

Labeled Function/Calculation/Number
OR
Function/Calculation/Number, Name

See this link for more information about the above terms. Two different methods are provided for convenience of the user. In the first case, the name for the new button is taken from the name of the label, and the contents are taken from the labeled contents (see link). In the second case, the name and the contents are provided as separate entries.

Types of User Defined Buttons

Function [SaveFunction]: For the stack entry or stack entries to be saved off as a function, the first stack entry must have at least one undefined Name. When the user presses the new function button, the saved off function will be evaluated with the undefined Names replaced in alphabetical order by the topmost entries on the stack (very much the way built in functions like the sin function works).
Constant [SaveConstant]: When the new button is pressed, only the name of the constant will appear on the stack. The constant will have the result value of the stored calculation and can be used in calculations similar to how the pi or e buttons work.
Saved Stack Entry [SaveEntry]: When the user presses the new button, the saved stack entry will reappear on the stack. This is useful if the user wants to recall previous calculations exactly as is rather than have the result appear as a constant.