I just remembered it was mostly inline asm, like <a href="http:&#x2F;&#x2F;sh1.webring.com&#x2F;people&#x2F;gu&#x2F;um_3792&#x2F;demos.html" rel="nofollow">http:&#x2F;&#x2F;sh1.webring.com&#x2F;people&#x2F;gu&#x2F;um_3792&#x2F;demos.html</a><p>ps: here is the description in pseudo code (4 lines near bottom) <a href="http:&#x2F;&#x2F;pascal.sources.ru&#x2F;demo&#x2F;otfire.htm" rel="nofollow">http:&#x2F;&#x2F;pascal.sources.ru&#x2F;demo&#x2F;otfire.htm</a><p>tl;dr: it&#x27;s a very approximative diffusion process.