Index Register Arithmetic; Exchanging The X-Register; Indirect Branching With - HP -15C Owner's Handbook Manual

108 Section 10: The Index Register and Loop Control
If R
contains:
I
21
22
23
24
⋮
65
 0 only.
*For R
I

Index Register Arithmetic

Direct. O or l { + , -, *, ÷ } V. Storage or recall
arithmetic operates with the Index register in the same manner as upon
other data storage registers (page 43).
Indirect. O or l { + , -, *, ÷ } % carries out storage
or recall arithmetic with the contents of the data storage register addressed
by the integer portion of the number (0 to 65) in the Index register. See the
above table.

Exchanging the X-Register

Direct. ´ X V exchanges contents between the X-register and the
Index register. (Works the same as X n does with registers 0 through .9.)
Indirect. ´ X % exchanges contents between the X-register and the
data storage register addressed by the number (0 to 65) in the Index register.
See the above table.

Indirect Branching With

The V key—but not the % key—can be used for indirect branching
(tV) and subroutine calls (GV). (Only the integer portion of
the number in R
storage registers).
Indirect Addressing
% will address:
R
21
R
22
R
23
R
24
⋮
R
65
V
is used.) (% is only used for indirect addressing of
I
t V or GV will
transfer to:*
´ b B
C
" "
Á
" "
E
" "
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