Справочник Пользователя для HP (Hewlett-Packard) HP 33s

3.  The stack drops. 

„

Notice that when the stack lifts, it replaces the contents of the T– (top) register 
with the contents of the Z–register, and that the former  contents of the 
T–register are lost. You can see, therefore, that the stack's memory is limited 
to four numbers. 

„

Because of the automatic movements of the stack, you do not need to clear 
the X–register before doing a new calculation. 

„

Most functions prepare the stack to lift its contents when the next number 
enters the X–register. See appendix B for lists of functions that disable stack 
lift. 

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 lost

2 lost

1

2

3

3

3

2

3

4

4

3

3

4

5

5

4

4

5

5

6

11

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. 

Y ou 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.