HP HP-67 - Indirect Display Control

Using the I-Register for Indirect Control 225
You can already see that using the I-register and [0, (5z(), and
in conjunction with these other functions gives you a tremen-
dous amount of computing power and exceptional programming
control. Now let’s have a closer look at these operations.
Indirect Display Control
You can use the current number in the I-register in conjunction
with the EE3 key to control the number of decimal places to which a
number is displayed and printed. When 53 (@ is performed, the
display is seen rounded to the number of decimal places specified by
the current value contained in the I-register. (The display is seen
rounded, but of course, the calculator maintains its full accuracy, 10
digits multiplied by 10 raised to a two-digit exponent, internally.)
The number in the I-register can be any value, positive or negative,
from O through 9. The CE@ [@ operation is most useful as part of
a program, but it can also be executed manually from the keyboard.
For example:
Slide the W/PRGM-RUN switch werem [lIMIRuN to RUN.
Press Display
50
o Normal FIX 2 display.
@ 0.00000 FIX 5 display specified
because of the number 5
that is stored in the
I-register.
o0 (st 9.00000
R @ 9.000000000 FIX 9 display selected by
the number in the
I-register.
Thus,
by
controlling
the
number
in
the
I-register,
you
can
control
many
different
display
options
with
very
few
instructions
in
a
program.