Zodiac constellations can be traced even further back, to Bronze Age (First Babylonian dynasty) sources, including Gemini "The Twins", from MAŠ.TAB.BA.GAL.GAL "The Great Twins", and Cancer "The Crab", from AL.LUL "The Crayfish", among others. Around the end of the 5th century BC, Babylonian astronomers divided the ecliptic into twelve equal "signs", by analogy to twelve schematic months of thirty days each. Each sign contained thirty degrees of celestial longitude, thus creating the first known celestial coordinate system. Unlike modern astronomers, who place the beginning of the sign of Aries at the place of the Sun at the vernal equinox; Babylonian astronomers
Tapwave Zodiac initially available in two models, Zodiac 1 (32MB), and Zodiac 2 (128MB). The Zodiac 2 was $100 more expensive than the original Zodiac. Games which utilized some or all of the Zodiac's hardware/software are incompatible with standard Palm OS devices. This does exclude platforms outside of Palm OS (e.g., Doom II is also out for PC, but the Zodiac version listed here won't run on standard Palm OS handhelds). This list also excludes standard Palm OS games which are also available for Zodiac handhelds, which were either identical or slightly improved on Zodiac, called "Zodiac tuned" (e.g. a game available