HP 113394 User Guide - Page 232

232 Appendix A: RPN and the Stack When an arithmetic operation or q is performed, the answer is placed in the X-register, the number formerly in the X-register is copied into the LAST X register, and the stack drops. When the stack drops, the number in the Z-register is copied into the Y-register, and the number in the T-register is copied into the Z-register but also remains in the T-register. The diagram on the next page illustrates the stack operation when 8 ÷ 2 is calculated. (Assume that the stack and LAST X registers have already been loaded with the numbers shown as the result of previous calculations.) Percentage Functions When any of the three percentage functions is performed, the answer is placed in the X-register, the number formerly in the X-register is copied into the LAST X register, but the stack does not drop. The numbers in the Y-, Z-, and T-registers are not changed when a percentage function is performed. File name: hp 12c pt_user's guide_English_HDPMF123E27 Page: 232 of 275 Printed Date: 2005/8/1 Dimension: 14.8 cm x 21 cm