TellStar was the first graphical astronomy program ever available for personal computers. It was sold from 1980-1986 by Scharf Software Services, and was available for the Apple II and IBM PC computers. It came in two versions; Level 1, which only plotted the northern hemisphere, and Level 2, which was able to plot the entire sky.TellStar could predict the position of celestial objects on any point of the earth at any time between 0 and 3000AD.