HP 113394 User Guide - Page 131

Section 9: Branching and Looping 131 RPN program notes: We'll key the income into the display before running the program so that it will be in the X-register when the :0 instruction in program line 001 is executed. This instruction will place the test value 20,000 in the X-register and (as explained in Appendix A) move the income into the Y-register. The ~ instruction in program line 002 will exchange the numbers in the X- and Y-registers (as also explained in Appendix A): that is, it will place the income back into the X-register and place the test value into the Y-register. This is necessary because when either the :2 instruction in line 005 or the :1 instruction in line 007 is executed, the number in the X-register is moved into the Y-register; if the ~ instruction were not included, the test value 20,000, rather than the income, would be in the Y-register when the b instruction in line 008 is executed. Keystrokes (RPN mode) Display f] fs 007,43, 33,002 Sets calculator to Program mode. (Display shows program line at which execution was halted at end of preceding example.) fCLEARÎ 000, Clears program memory. :0 001, 45 0 Recalls test value into X-register and places income in Y-register. ~ 002, 34 Places income in X-register and test value in Y-register. File name: hp 12c pt_user's guide_English_HDPMF123E27 Page: 131 of 275 Printed Date: 2005/8/1 Dimension: 14.8 cm x 21 cm