HP 17bII manual RPN The Stack, What the Stack Is

E

RPN: The Stack

This appendix explains how calculations take place in the automatic memory stack and how this method minimizes keystrokes in complicated calculations.

What the Stack Is

Automatic storage of intermediate results is the reason that RPN mode easily processes complicated calculations－without using parentheses. The key to automatic storage is the automatic RPN memory stack.

The memory stack consists of up to four storage locations, called registers, which are “stacked” on top of each other. It is a work area for calculations. These registers －labeled X, Y, Z, and T －store and manipulate four current numbers. The “oldest” number is the one in the T-(top) register.

T

Z

Y

X

0.00“Oldest” number

0.00Displayed (most “recent” number)

The most “recent” number is in the X-register: This is the number you see in the display.

268 E: RPN: The Stack

File name : 17BII-Plus-Manual-E-PRINT-030709 Print data : 2003/7/11