T

Z

Y

1X

1

1

2

1

1

2

3

1

2

C

4

1

0

3

5

1

3

1.Lifts the stack

2.Lifts the stack and replicates the X–register.

3.Overwrites the X–register.

4.Clears x by overwriting it with zero.

5.Overwrites x (replaces the zero.)

The LAST X Register

The LAST X register is a companion to the stack: it holds the number that was in the X–register before the last numeric function was executed. (A numeric function is an operation that produces a result from another number or numbers, such as .)

Pressing returns this value into the X–register.

This ability to retrieve the "last x" has two main uses:

1.Correcting errors.

2.Reusing a number in a calculation.

See appendix B for a comprehensive list of the functions that save x in the LAST X register.

2-8RPN: The Automatic Memory Stack

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Image 54
HP 35s Scientific manual Last X Register, 8RPN The Automatic Memory Stack