HP HP-15C, Руководство пользователя

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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
cases, the above effects will come so naturally that you won’t even think
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.