User manual HP F2221AA

[. . . ] Reproduction, adaptation, or translation of this manual is prohibited without prior written permission of Hewlett-Packard Company, except as allowed under the copyright laws. 2-1 The X and Y­Registers are in the Display. 2-3 Exchanging the X­ and Y­Registers in the Stack. It identifies examples or keystrokes that are shown in RPN mode and must be performed differently in ALG mode. [. . . ] A program lets you repeat operations and calculations in the precise manner you want. In this chapter you will learn how to program a series of operations. In the next chapter, "Programming Techniques, " you will learn about subroutines and conditional instructions. To find the area of a circle with a radius of 5, you would use the To get the result for this circle, 78. But what if you wanted to find the area of many different circles?Rather than repeat the given keystrokes each time (varying only the "5" for the different radii), you can put the repeatable keystrokes into a program: This very simple program assumes that the value for the radius is in the X­ register (the display) when the program starts to run. It computes the area and leaves it in the X­register. In RPN mode, to enter this program into program memory, do the following: Try running this program to find the area of a circle with a radius of 5: This sets the program to its beginning. In ALG mode, to enter this program into program memory, do the following: Try running this program to find the area of a circle with a radius of 5: This sets the program to its beginning. We will continue using the above program for the area of a circle to illustrate programming concepts and methods. The following topics show what instructions you can put in a program. What you put in a program affects how it appears when you view it and how it works when you run it. selecting a Mode Programs created and saved in RPN mode should be edited and executed in RPN mode, and programs or steps created and saved in ALG mode should be edited and executed in ALG mode. If you want more than one program stored in program memory, then a program needs a label to mark its beginning (such as ) and a return to mark its end (such as ). Notice that the line numbers acquire an to match their label. Program Labels Programs and segments of programs (called routines) should start with a label. The label is a single letter from A through Z. The letter keys are used as they are for variables (as discussed in chapter 3). You cannot assign the same label more than once (this causes the message ), but a label can use the same letter that a variable uses. It is possible to have one program (the top one) in memory without any label. However, adjacent programs need a label between them to keep them distinct. Programs can not have more than 999 lines. [. . . ] Begins program execution at the current program line; stops a running program and displays the X­register. Displays the labeled contents of variable without recalling the value to the stack. Given a y­value in the X­register, returns the x­estimate based on the Moves x to the Y­register and y to the X­register. If xy, executes next program line; if x=y, skips next program line. [. . . ]