In 1977 and 1978, I studied the tile structures described by Doctor Heinrich Heesch and applied
that to computer graphics. The programs were written in FORTRAN. The images were black
and white line drawings. The computer output were vector graphics devices with hardware
limitations. The basic method to generate Escher tiles was published in 1979 in "Computer
Graphics and Image Processing" from pages 333 to 353. The entire publication is shown
here in GIF images.

Heech's explanation of 28 basic interlocking tiles

Use of tessellations in art and product design 1980

Product design with Solid Works