Computers and Astrology

Mark Pottenger

I am writing this article with my own biases strongly in evidence. I like computers and expect most people to feel that way soon if they don’t already.

The computer is a misnamed machine. A computer is a machine that follows instructions. Mathematical computation, while an important part of the power of computers, is still only a part. Given adequate hardware, a computer can do anything that can be described precisely enough. For example, our computer calculates charts, stores our mailing list, prints out mailing labels for subscribers, stores and manipulates text, and even prints out the camera-ready copy of the pages you are reading.

Computer technology is a new and rapidly changing field. The first generations of computers, starting in 1946, were vacuum tube monstrosities. The latest computers pack the same power into a fraction of the space for a fraction of the price. Modern computers are made from integrated circuits, in which there are no separate components or wires. If you are interested in the hardware, I recommend the September 1977 issue of Scientific American, which was entirely devoted to microelectronics.

Computers are often divided into three size categories (although there is no real agreement on the exact dividing lines). Regular, or mainframe, computers fill one or more rooms and cost millions of dollars. Minicomputers are in the same size range as refrigerators and cost tens of thousands of dollars. Microcomputers are suitcase size and cost hundreds of dollars. Peripheral equipment for each type of computer tends to be in the same size and price range, though there is overlap.

These distinctions are actually somewhat misleading. Today’s micros are as powerful as the first mainframes. A modern microcomputer is a very powerful machine, more than enough for the needs of most astrologers. And computer power is still increasing while price is decreasing. For an introduction to computers and the excitement of recent developments I recommend the book The Home Computer Revolution by Ted Nelson.

To give some idea of computer power, Neil Michelsen’s beautiful system (Astro Computing Services) is a minicomputer. If all you want is a system to do personal or client charts or perhaps a small research project, a microcomputer can do the job. (Also, for people who like to play, there are a tremendous lot of game programs available for micros.)

Microcomputers have only been around for four years, and the first two of those years you had to build them from kits. Our system was assembled by Rique Pottenger. Since 1977, pre-built (assembled) microcomputers have been available (with the Commodore “PET” leading by a few months). Now there are so many brands of microcomputer it is difficult to keep track. A few names are TRS-80, Apple II, Sorcerer, and Horizon, but there are about 50 brands available. The Radio Shack TRS-80 is the microcomputer with the most sales to date.


I have already said that a computer is a machine that follows instructions. Obviously, it won’t do anything until it receives those instructions, which are called programs or software (in contrast to the physical hardware). The instructions the machine follows are in a form quite different from ordinary human languages. Rock bottom level in a machine is two valued: current flowing or no current; one or zero. This rock bottom binary digit (bit) is grouped into units called bytes (8 bits) or words (16 bits) which can have many values. Writing programs at the byte level, however, calls for tremendous attention to detail. There are a number of “high level languages” available that permit programs to be written in forms much closer to normal speech or thought patterns. The language interpreter or compiler, which is itself a program, takes the high level program and puts it in a form the machine can use. Most of the microcomputers now available come with a BASIC interpreter. BASIC is a fairly easy to learn language, but it is not very standardized.

While developing programs can be easy, it can also be quite difficult at times, especially when you are unsure exactly how to do what you want. Since most astrologers are unfamiliar with celestial mechanics and spherical trigonometry it is better to let someone else work out the programs. A number of programs written by Rob Hand and other more technically inclined astrologers are now available. Michael and Margaret Erlewine (1041 N Main St; Ann Arbor, MI 48104) have started a software magazine (Matrix) and a service to sell software (Matrix Software). Matrix Magazine gives listings of programs for programmable calculators and for computers, plus articles on various technical aspects of astrology (astronomy) and computers. Matrix Software offers programs on cassette for the PET, the TRS-80, and probably other computers by now. They also sell PETs.

Even if you do buy ready to run tapes, you will probably need to learn some programming to use a normal microcomputer. If you absolutely don’t want to program there is an option available. The DR-70 from Digicomp Research Corp (Terrace Hill; Ithaca, NY 14850) is already programmed and can’t be changed. The price is somewhat more than an ordinary microcomputer, but it has a large selection of astrological programs available as soon as the power goes on. The programs are in permanent memory in the computer with no high level language needed. Included are planetary routines good for several thousand years and a wide variety of house systems and current pattern systems. It can even compare charts. If all you want is personal charts it is great—especially since it is portable. However, if you are interested in research, it is not as satisfactory because you can’t store large numbers of charts.

If you want a computer but aren’t quite sure exactly which one, contact ASI (ASI Computer Services Division; New York Astrology Center; 127 Madison Ave; New York, NY 10016). They have a questionnaire to clarify what you want, and they sell microcomputers and software. They offer to tailor a system to your needs.

In the past decade computers have done a lot for astrology. They have made possible a new generation of more accurate ephemerides, including ephemerides of asteroids previously unavailable. They have been instrumental in carrying out a number of research projects that would probably not have been attempted without them. They have provided charts we can trust to be free of mathematical blunders. They have provided many new ways of looking at charts that would be terribly time consuming to calculate by hand (e.g. midpoint sorts, harmonics, Jim Lewis’s Astro*Carto*Graphy). They have generally freed astrologers from computational chores and let them spend more time with their clients and charts.

One thing that has been tried on computers but not very successfully carried out is interpretation of charts. So far, interpretation programs have taken bits and pieces but failed to integrate them. What the future holds for computer interpretation, I don’t know.

In the next decade, I expect to see a tremendous increase in the number of computers owned by astrologers. As more people use computers, more uses for computers will be invented. I expect there will be techniques in common use ten years from now that haven’t even been invented yet. Computers will greatly expand the flexibility of astrologers. I also hope astrological research will be aided by the widespread use of computers. Unquestionably, home computers will continue to improve the accuracy of the charts astrologers use—no more dropped figures or hurried calculations. Some commercial services, such as the wheel (and other graphics) in Astro Computing Services charts or Jim Lewis’s Astro*Carto*Graphy maps will be hard to equal at reasonable prices, but many can be equaled.

I am looking forward to computer developments in the decade ahead, and hope my readers are too!

Copyright © 1979 Los Angeles Community Church of Religious Science, Inc.

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