HP 12C - Page 131

Section 9: Branching and Looping 131
File name: hp 12c pt_user's guide_English_HDPMF123E27 Page: 131 of 275
Printed Date: 2005/8/1 Dimension: 14.8 cm x 21 cm
RPN program notes:
We’ll key the income into the display before running the
program so that it will be in the X-register when the
:
0 instruction in program
line 001 is executed. This instruction will place the test value 20,000 in the
X-register and (as explained in Appendix A) move the income into the Y-register.
The
~
instruction in program line 002 will exchange the numbers in the X- and
Y-registers (as also explained in Appendix A): that is, it will place the income back
into the X-register and place the test value into the Y-register. This is necessary
because when either the
:
2 instruction in line 005 or the
:
1 instruction in
line 007 is executed, the number in the X-register is moved into the Y-register; if the
~
instruction were not included, the test value 20,000, rather than the income,
would be in the Y-register when the
b
instruction in line 008 is executed.
Keystrokes
(RPN mode)
Display
f]
fs
007,43, 33, 002
Sets calculator to Program mode.
(Display shows program line at
which execution was halted at
end of preceding example.)
f
CLEAR
Î
000,
Clears program memory.
:
0
001, 45 0
Recalls test value into X-register
and places income in Y-register.
~
002, 34
Places income in X-register and
test value in Y-register.