HP HP-67 - Page 244

240 Using the I-Register for Indirect Control
{3 are addressed, while positive 15 through 19 address @
through (€. Label addressing is illustrated below.
If the number @ or @
inIis: transfers execution to:
0
N
O
WN
=
O
=)
(=)
[
JBE0H
=)
D)
of ||
2|
=] 5]
[=
1Tl
- o -~
10
11
12
13
14
15
16
17
18
19
BEE
NERDCEERAREEEEE
— o -
| @]
@
~l|~
|
=
B
E
- @ -
-
©
oooooSOcSa0ooDEEaEes
Remember that the numbers in the I-register must be positive or
zero (negative numbers cause rapid reverse branching, which we will
discuss later), and that the calculator looks at only the integer portion
of the number in I when using it for an address.
Example: One method of generating pseudo random numbers in a
program is to take a number (called a ‘‘seed’’), square it, and then
remove the center of the resulting square and square that, etc. Thus,
a seed of 5182 when squared yields 26853124. A random number
generator could then extract the four center digits, 8531, and square
that value. Continuing for several iterations through a loop would
generate several random numbers.