Rapid Reverse Branching - HP -67 Owner's Handbook Manual

244 Using the I-Register for Indirect Control
Were you to record this program on a magnetic card, you might wish
to mark your card so that it looked like this:
fiPse00 KANOom NumSER Geneedrar»
g
U008 20307 841L7:00a 2 2
Now run the program for seeds of 5182, .5182 and 51.82. To run the
program:
Slide the W/PRGM-RUN switch wereM [llMRUN to RUN.
Press Display
51828 Random number gen-
erated in the proper form.
5182
51.820
The program generates a random number of the same form as the
seed you keyed in. To use the random number as a new seed (simu-
lating the operation of an actual random number generator, in which a
loop would be used to decrease the apparent predictability of each
succeeding number), continue pressing the appropriate user-definable
key:
Press Display
Each succeeding number
51.28 appears to be more
29.63 random.
With a few slight modifications of the program, you could have used
an [ [@ instruction instead of the @ instruction.
Rapid Reverse Branching
Using @ and {@, with a negative number stored in I,
you can actually branch to any step number of program memory.