Patent US 4,490,789

Non-alphabetic characters are reproduced by feeding into a computer symbols defining the gross form of each character, then feeding in successive pairs of symbols, with one symbol in each pair defining an element of the character and another symbol defining the juxtaposition of each element relative to previous elements. The operation of the computer is fixed by a program to cause a plotter to draw the elements in accordance with their juxtaposition and thereby form the characters.