Reviewing The Stack (Roll Down); Exchanging The X- And Y-Registers In The Stack - HP 17bll+ User Manual

Reviewing the Stack (Roll Down)

The (roll down) function (on the
~
contents of the stack by "rolling" the contents downward, one register at
a time. While in RPN mode you don't need to press the shift key for
The key has the same effect as
]
when affects the list and not the stack. Likewise, the
]
contents of the stack upward, except in lists.
Rolling a Full Stack. Suppose the stack is filled with 1, 2, 3, 4 (press 1
2 3
E E
the way around and back to where they started:
T
1
Z
2
Y
3
X
4
When you press
T-register. Notice that the contents of the registers are rolled, while the
registers themselves maintain their positions. The calculator displays
only the X-register.
Variable Stack Size. Clearing the stack by pressing
the stack to one register (X) with a zero in it. As you enter numbers, the
stack builds up again. The
registers as currently exist (one, two, three, or four).

Exchanging the X- and Y-Registers in the Stack

Another function that manipulates the stack contents is
y), located on the
without affecting the rest of the stack. Pressing
original order of the contents. While in RPN mode you don't need to
press the shift key for
4). Pressing
E
4
1
2
~ ~
3
, the value in the X-register rotates around into the
~
and
~
key. It swaps the contents of the X- and Y-registers
)
.
x
key) lets you review the entire
(
. except in a CFLO or SUM list,
~
four times rolls the numbers all
~
3 2
4 3
1 4
~
2 1
@c
functions roll through as many
[
x
E: RPN: The Stack 269
~
key rolls the
[
1
2
3
~
4
reduces
(x exchange
x
again restores the
.