Started by Callie Sutherland (@bytebard) ·
finally watched the 'parallel universes' video
The A Button Challenge: collect stars pressing A as few times as possible. The explanation for one 'half an A press' route involves building up speed for hours so Mario can reach copies of the level that only exist because of how positions get stored. Understood maybe 60% of it and loved all of it.
5 sources · 1h 23m down the hole
How I got here
- Started with
- “watch for rolling rocks 0.5 a presses”
- Ended at
- Floating-point arithmetic
The Trail
- “watch for rolling rocks 0.5 a presses” (youtube.com)
the whole thing. twice
- Super Mario 64 (en.wikipedia.org)
- “super mario 64 a button challenge explained” (google.com)
- “super mario 64 backwards long jump why it works” (google.com)
- Floating-point arithmetic (en.wikipedia.org)
What I came away with
Mario's position is stored as floats, but floor collision works on 16-bit integer versions of it, so the level's floors effectively repeat every 65,536 units. Go fast enough and you can land on those 'parallel universe' copies. And the backwards long jump, until a later Japanese re-release patched it, let Mario build up basically unlimited speed on stairs.
Keep going
- did Apple really steal the GUI from Xerox? · Callie Sutherland · 7 sources
- phone phreaks whistled into the phone network · Callie Sutherland · 5 sources
- Flash stopped on January 12, 2021, and people saved 160,000 games · Ayodele Bankole · 7 sources
- the four color theorem was the first big proof nobody could check by hand · Henrik Larsen · 5 sources