SATO Motif

HP-48 Calculator Compass Documentation


Table of Contents

General Issues
Overview
Program Operation
Warning
Program Algorithm
A Rhetorical Question
Compatibility Issues
About the Author
Correspondence
Version Release Dates


General Issues

The Calculator Compass program is freeware. It is not to be bought or sold. The program and documentation may be copied freely provided that the program and/or documentation are not altered in any way and that they are distributed as you received them (that is to say, in a single compressed file containing the program and documentation, and any other accompanying files). A service fee may be charged only for the distribution process. You may alter the program for your personal use but you may not distribute any altered version without prior written permission from the copyright owner.

The above privileges do not involve transfer of intellectual property rights such as copyright ownership. Copyright © 1991, 1992, 2000 by Junichi Steven Sato. All rights reserved.

THE PROGRAM AND DOCUMENTATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. SHOULD THE PROGRAM AND/OR DOCUMENTATION PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

IN NO EVENT SHALL THE COPYRIGHT OWNER OF THIS PROGRAM AND DOCUMENTATION BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM AND/OR DOCUMENTATION, EVEN IF THE COPYRIGHT OWNER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Return to the Table of Contents


Overview

Whether you're lost in the Sahara Desert in Africa, the Great Sandy Desert in Australia, or in an unknown city in the United States, you can use the HP-48 Calculator Compass program to determine approximately which way you're heading. To receive reasonable readings, though, you must:

  1. have an HP-48 with this Calculator Compass program
  2. have the correct time on the calculator
  3. know whether you're in the Northern or Southern Hemisphere, and
  4. have the sun shining.

Return to the Table of Contents


Program Operation

Start the program by evaluating 'COMPASS'. This program will not work properly if system flags -17, -18 and/or -55 are/is set. The program creates the reserved variable 'PPAR' if one does not exist already, and may modify it if there is one. 'COMPASS' does not require anything from the stack.

When the program prompts for the hemisphere, enter "S" if you're in the Southern Hemisphere and enter anything else if you're in the Northern Hemisphere. The screen will then display an arrow pointing to a certain direction. Position the calculator so that this arrow is pointing toward the sun. This can be done in many ways. One way is to take a pen or a similar object and stand it perpendicular to the earth. Position the calculator so that the object is casting a shadow over the arrow, which, in turn, should be pointing directly at the object. Do not look directly into the sun! Press the ATTN key.

The screen should then be displaying two arrows. The shorter one should still be pointing at the sun. The longer one should be pointing north. Press ATTN again to return to the stack.

Return to the Table of Contents


Warning

Sunlight is known to dissolve lead display. Do not keep your calculator exposed to direct sunlight for a prolonged period of time.

Return to the Table of Contents


Program Algorithm

As one may suspect, the program does not use magnets to find which way north is. Rather, it uses the time of day and the position of the sun. The program internally builds itself an analog clock. In the Northern Hemisphere, if the hour hand of an analog clock is pointing toward the sun, south is halfway between the "12" and the hour hand. North, needless to say, is the opposite way. In the Southern Hemisphere, if the "12" is pointing toward the sun, north is halfway between the "12" and the hour hand. Take a closer look at how the program works by using the DEBUG command.

Return to the Table of Contents


A Rhetorical Question

The next time you're lost in the Sahara Desert, this program will give you an answer to the question "Which way is north?"

...Which in turn leads to a second question: "What in the world am I doing in the Sahara Desert with an HP-48!?"

Return to the Table of Contents


Compatibility Issues

Because the Calculator Compass program was developed for and only tested on the HP-48SX, compatibility issues may arise if you are trying to use the program on anything other than the HP-48S series (the newer HP-48G series, for example). It is also possible that a library or add-on ROM card may cause conflicts with the program.

Return to the Table of Contents


About the Author

Junichi Steven Sato holds a Bachelor of Music Degree with Honors in Piano Performance from DePaul University and a Master of Music Degree in Piano Performance with a Cognate in Composition from Indiana University. Junichi has been the recipient of numerous musical awards and honors and is actively involved as a pianist, teacher, composer, arranger, and publisher.

Junichi's hobbies include computer and calculator programming. Some of his programs for the Hewlett-Packard HP-48S series are well-known and are widely distributed on the internet. The latest releases of these programs can be found at http://neecher.net/hp48/.

Return to the Table of Contents


Correspondence

Due to time limitations, not all submissions will be answered, but please feel free to submit correspondence regarding the Calculator Compass program by sending an e-mail to Junichi Steven Sato at junichi@neecher.net.

Return to the Table of Contents


Version Release Dates

Release Date Checksum Bytes
Version 1.0 August 1991 #44571d 488
Version 1.1 August 1991 #47093d 485.5
Version 1.2 June 1992 #28929d 531.5

Return to the Table of Contents


[ Main Page | Official Bio | What is Neecher? ]
[ Work Listing | Audio Clips | Photos ]
[ Beethoven Quiz | HP-48 Programs | Chess Games ]
[ Favorite Links | Terms of Use ]

Main Page

Use of this site indicates you accept the Terms of Use