This Hacker News discussion celebrates the 50th anniversary of BitBLT, a fundamental image manipulation routine. The initial post links to a Mastodon post about the anniversary and an interview with its inventor, Dan Ingalls. The conversation quickly branches out, with users sharing related resources like a Byte Magazine article from 1981 detailing BitBLT, and a link to XScreensaver’s “Blitspin” hack. A notable thread discusses jwz.org’s (the blog author) apparent dislike of Hacker News, with users noting a referral tracker on his site. Finally, a tangent emerges regarding software complexity, with a user proposing “43FF’s Law” – that complexity is measured by nested for-loop depth – and a brief correction about the origins of “FOR” loops versus DO loops in early programming languages. A final comment points out BitBLT’s potential for copyright infringement.