210 Appendix B: Stack Lift and the LAST X Register
Disabling Operations
Stack Lift.
There are four stack-disabling operations on the calculator.
*
These operations disable the stack lift, so that a number keyed in after one
of these disabling operations writes over the current number in the
displayed X-register and the stack does not lift. These special disabling
operations are:
v
`
z
w
Imaginary X-Register.
A zero is placed in the imaginary X-register when
the next number following
v
,
z
, or
w
is keyed or recalled into
the display (real X-register). However, the next number keyed in or recalled
after
−
or
`
does not change
the contents of the imaginary X-
register.
Enabling Operations
Stack Lift.
Most of the operations on the keyboard, including one-and two-
number mathematical functions like
x
and
*
, are stack-enabling
operations. This means that a number keyed in after one of these operations
will lift the stack (because the stack has been ―enabled‖ to lift). Both the
real and imaginary stacks are affected. (Recall that a shaded X-register
means that its contents will be written over when the next number is keyed
in or recalled.)
T
t
z
y
y
Z
z
y
x
x
Y
y
x
4.0000
4.0000
X
x
4
4.0000
3
Keys:
4
v
3
(Assumes
stack
enabled.)
Stack
lifts.
Stack
disabled.
No stack
lift.
*
Refer to footnote, page 36.
Summary of Contents for HP-15C
Page 1: ...HP 15C Owner s Handbook HP Part Number 00015 90001 Edition 2 4 Sep 2011 ...
Page 17: ...Part l HP 15C Fundamentals ...
Page 64: ......
Page 65: ...Part ll HP 15C Programming ...
Page 118: ...118 ...
