HP HP-15C - Calculator Functions and the Stack

36 Section 3: The Memory Stack, LAST X, and Data Storage
Keystrokes
Display
*
287.0000
Reverses the function that
produced the wrong answer.
13.9 +
20.6475
The correct answer.
Calculator Functions and the Stack
When you want to key in two numbers, one after the other, you press
v between entries of the numbers. However, when you want to key
in a number immediately following any function (including manipulations
like )), you do not need to use v. Why? Executing most HP-15C
functions has this additional effect:

The automatic memory stack is lift-enabled that is, the stack will lift
automatically when the next number is keyed or recalled into the
display.

Digit entry is terminated, so the next number starts a new entry.
lost
T
t
t
z
z
Z
z
z
y
z
Y
y
y
2
y
X
4
2
5
7
Keys:
¤
5
+
There are four functions  v, `, z, and w  that disable stack
lift.
*
They do not provide for the lifting of the stack when the next number is
keyed in or recalled. Following the execution of one of these functions, a new
number will simple write over the currently displayed number instead of causing
the stack to lift. (Although the stack lifts when v is pressed, it will not lift
when the next number is keyed in or recalled. The operation of v
illustrated on page 34 shows how v thus disables the stack.) In most
     
about them.
*
− will also disable the stack lift if digit entry is terminated, making − clear the entire display like
`. Otherwise, it is neutral. For a further discussion of the stack, refer to appendix B.