HP HP-67 - Page 256

252 Using the I-Register for Indirect Control
b. Now create and load a program immediately after the
first one that will recall and display the contents of each
storage register in reverse order (that is, display Rg first,
then Rp, etc.). The program should stop running after it has
displayed the contents of R,.
Run the program you loaded for Problem 1a, keying in a series
of 25 different values. Then run the program you loaded for 1b.
All 25 values should be shown, but the last one you keyed in
should be the first displayed, etc.,
Modify the Random Number Generator program on pages 242-
243 to use instead of [@ for control. Run the
program with the same seed numbers to ensure that it still
runs correctly.
One curious fact about the Fibonacci series is that the quotients
of successive terms converge to a common value. This value
was known to the ancient Greeks as the ‘‘golden ratio’’ because
it expressed the ideal ratio of width to length that gave the most
aesthetically appealing building or room.
Create, load, and run a program
that will yield this ideal ratio.
You should be able to calculate
and display each successive ratio
(for example, 2/3, 3/5, 5/8, 8/13,
etc.,) until the series converges to
the value of the golden ratio.
Create a loop by using the rapid
reverse branching power of the
{@ instruction with a nega-
tive number in the I-register. Use
the flowchart on page 253 to help
you.
When you run the program and are satisfied that the golden
ratio has been calculated, you can press from the keyboard
to stop the infinite loop. (The value of the golden ratio should be
0.618033989.)