HP -32S Owner's Manual page 38

T
0.0000
Z
0.0000
Y
0.0000
X
0.0000
"Oldest" number
Displayed
The most 'recent* number is in the X-register: this is the number you
see in the display.
In programming, the stack is used to perform calculations, to tempo
rarily store intermediate results, to pass stored data (variables) among
programs and subroutines, to accept input, and to deliver output.
The X-Register Is in the Display. The X-register is what you see
except when a menu, a message, or a program line is being displayed.
You might have noticed that several functions' names include an x or
y. This is no coincidence: these letters refer to the X- and Y-registers.
For example, Hi 10*1 raises ten to the power of the number in the X-
register (the displayed number).
Hi clear I {x} versus [c]. Pressing Hi clear I {*} always clears the
X-register to zero, and it is also used to program this instruction. The
I"c1 key, in contrast, is context-sensitive. It either clears or cancels the
current display, depending on the situation: it acts like Ml clear I {x}
only when the X-register is displayed.* It cancels other displays:
menus, labeled numbers, messages, and program entry.
Reviewing the Stack (|R+ I)
The IR+I (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.
*@] also acts like 111 CLEAR I {*} when the X-register is displayed and digit entry is termi
nated (no cursor present).
36 2: The Automatic Memory Stack