HP HP-15C - Page 44

44 Section 3: The Memory Stack, LAST X, and Data Storage
The number in the register is determined as follows:
For storage arithmetic,
new contents
of register
=
old contents
of register


×

number in
display
R
0
r
T
t
R
0
r-x
T
t
Z
z
Z
z
Y
y
Y
y
X
x
X
x
Keys:
O-0
Recall Arithmetic. Recall arithmetic allows you to perform arithmetic with
the displayed value and a stored value without lifting the stack, that is,
without losing any values from the Y-, Z, and T-registers. The keystroke
sequence is the same as for storage arithmetic using l in place of
O.
For recall arithmetic,
new display
=
old display


×

contents of
register
R
0
r
T
t
R
0
r
T
t
Z
z
Z
z
Y
y
Y
y
X
x
X
x-r
Keys:
l-0