HP 33s Scientific manual Entering and Displaying Data, Using Input for Entering Data, @

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