How enter works – HP 35s Scientific Calculator User Manual

Page 52

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2-6

RPN: The Automatic Memory Stack

How ENTER Works

You know that

separates two numbers keyed in one after the other. In terms

of the stack, how does it do this? Suppose the stack is again filled with 1, 2, 3, and
4. Now enter and add two new numbers:

1. Lifts the stack.
2. Lifts the stack and replicates the X–register.
3. Does not lift the stack.
4. Drops the stack and replicates the T–register.



replicates the contents of the X–register into the Y–register. The next

number you key in (or recall) writes over the copy of the first number left in the X–
register. The effect is simply to separate two sequentially entered numbers.

You can use the replicating effect of

to clear the stack quickly: press 0



. All stack registers now contain zero. Note, however, that

you don't need to clear the stack before doing calculations.

Using a Number Twice in a Row

You can use the replicating feature of

to other advantages. To add a

number to itself, press



.

5+6

1 lost

2 lsot

T

1

2

3

3

3

Z

2

3

4

4

3

Y

3

4

5

5

4

X

4

5

5

6

11

1

2

3

4

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