The PLASMA effect is essentially a sin wave test I wrote first, using a look up table and plotting colors to every pixel on the screen. FLOOR (also called MODE7 on SNES) is an old effect again using look up tables to determine the texture step size when drawing scan lines on the screen. The SOLID duck is rendered using a scanline rasteriser, which turns triangles into lots of horizontal lines ready for rendering, very easy to write, but quite difficult to get running as fast as the hardware can do."
71M went on to write more great apps like FileAssistant and FileAssistant++