HP 33s hp 33s_user's manual_English_E_HDPM20PIE56.pdf - Page 169

Entering and Displaying Data The calculator's variables are used to store data input, intermediate results, and final results. (Variables, as explained in chapter 3, are identified by a letter from A through Z or i, but the variable names have nothing to do with program labels.) In a program, you can get data in these ways: „ From an INPUT instruction, which prompts for the value of a variable. (This is the most handy technique.) „ From the stack. (You can use STO to store the value in a variable for later use.) „ From variables that already have values stored. „ From automatic equation prompting (if enabled by flag 11 set). (This is also handy if you're using equations.) In a program, you can display information in these ways: „ With a VIEW instruction, which shows the name and value of a variable. (This is the most handy technique.) „ On the stack - only the value in the X-register is visible. (You can use PSE for a 1-second look at the X-register.) „ In a displayed equation (if enabled by flag 10 set). (The "equation" is usually a message, not a true equation.) Some of these input and output techniques are described in the following topics. Using INPUT for Entering Data The INPUT instruction ( { ‰ Variable ) stops a running program and displays a prompt for the given variable. This display includes the existing value for the variable, such as @ )  where "R" is the variable's name, "?" is the prompt for information, and 0.0000 is the current value stored in the variable. Simple Programming 12-11