HP (Hewlett-Packard) HP 33s ユーザーズマニュアル

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RPN: The Automatic Memory Stack 
2–3
Reviewing the Stack 
R (Roll Down)   
The 
 
(roll down) key lets you review the entire contents of the stack by 
"rolling" the contents downward, one register at a time. You can see each 
number when it enters the X–register. 
Suppose the stack is filled with 1, 2, 3, 4. (press 1 
‘
 2 
‘
 3 
‘
 4) 
Pressing 
 
 four times rolls the numbers all the way around and back to where 
they started: 
T
1
4
3
2
1
Z
2
1
4
3
2
Y
3
2
1
4
3
X
4
3
2
1
4
What was in the X–register rotates into the T–register, the contents of the T–register 
rotate into the Z–register, etc. Notice that only the contents of the registers are 
rolled — the registers themselves maintain their positions, and only the X– and 
Y–register's contents are displayed. 
Rµ (Roll Up) 
The 
 (roll up) key has a similar function to 
 
 except that it "rolls" the 
stack contents upward, one register at a time. 
The contents of the X–register rotate into the Y–register; what was in the T–register 
rotates into the X–register, and so on. 
T
1
2
3
4
1
Z
2
3
4
1
2
Y
3
4
1
2
3
X
4
1
2
3
4