This PSP program is a Maze Generator routine written in a few lines. The readme says:
Yes folks, this is the world’s smallest and simplest maze generator. The algorithm is only 3-5 lines of code! I originally invented the algorithm when I was in elementary school and I thought maybe someone out there can appreciate how simple algorithms can actually create complex patterns. Think of it as fractal for mazes or mandelbrot for mazes, where a simple formula can generate complex patterns.
Note that the font affects the look of the maze, so get a font that has slashes that extends to the corners. The default PSP one leaves gaps. Tilt your PSP slightly for common viewing angle. Re-runthe program for another maze. Source is included.