HP HP-67 - Page 185

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To run the program, slide the Program Mode switch wrram Il run
to RUN and press §. The program will begin displaying a table of
integers and their square roots and will continue until you press
from the keyboard or until the calculator overflows.
How it works: When you press I3, the calculator searches through
program memory until it encounters the 3 instruction that
begins the program. It executes that instruction and each subsequent
instruction in order until it reaches step 011, the 7 instruction.
The 7 instruction causes the calculator to search once again,
this time for a 7 instruction in the program. When it encounters
the 7 instruction loaded in step 004, execution begins again from
that 7. (Notice that the address after a instruction in a pro-
gram is a label, not a step number.)
001 a
002 ([
003 1
j—— > 004 [ 7
| 005
! 006 1
! 007 1
| 08 @
| 009
| 010 [ (Pause
l——— o 7
012 0
Since execution is transferred to the 7 instruction in step 004
each time the calculator executes the 7 instruction in step 011, the
calculator will remain in this “‘loop,’” continually adding one to the
number
in
storage
register
R, and
displaying
the
new
number
and
its
square
root.