When the moon is in the seventh hour and Jupiter aligns with Mars, when you are tired of the animated toilets and bored with beating up Gandalf, try your hand at 'serious' astrology with Astrocalc.

Whether you think it's a load of moonshine or not, serious practitioners will tell you there is a lot more to astrology than meeting tall dark handsome strangers on the cartoon page of the Daily Mail. What puts most people off is the sheer volume of calculations to be done to construct a complete birth-chart. Astrocalc provides a program aimed at beginners with a booklet outlining the principles of interpretation.

You need to know the time, date and place of birth. Once those are entered, the calculations are a matter of seconds. The program produces positions for the sun, moon and planets, plus the mid-heaven and Ascendant, the sign on the eastern horizon.

The program also lists the main aspects formed between planets, with their degree of exactitude. Astrocalc produces suites of programs for professional astrologers with those and other features.

The accuracy of the calculations varies. Fast-moving features such as the Ascendant or moon may be as much as 1' out, but most features are accurate to about 4' of arc.

The booklet provides an explanation of the principles behind astrology, and does explore some of the more feckless criticisms levelled against it. It is not a very readable piece, and becomes quite turgid when discussing interpretation.

Nevertheless, Astrocalc does provide, albeit unattractively presented, an easy introduction to the arcane secrets of the stars. Interested people should therefore be able to judge astrology's claims for themselves. As Newton once remarked to the astronomer Halley in defence of the subject, "I, sir, have studied it. You have not."