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Numberphile: 255 and Pac-Man

submitted by Skeeve

1 decade 3 years 4 weeks ago

From Brady Haran's new video series, Numberphile: explaining binary to understand why Pac-Man becomes unplayable after 255 levels.

5 Comments

But you can get a score much higher than 255. What gives?

Well, this explanation is what happens on the hardware level, i.e. in the wiring inside the CPU. On the software side you can emulate the carry-over by allocating several pieces of memory and checking bounds and doing carry-over manually. So you're manually programming around the hardware constraints.

Trouble here is, the programmer has to anticipate that the given constraint isn't sufficient for the use case and needs to be worked around. For scores this was obviously the case. For the levels, I'm pretty sure that noone ever really anticipated that someone would go through 255 levels of pacman.

It's basically the same expectation management on a human level that brought us the fear of the Y2K problem.

Moving this video to Skeeve's personal queue. It failed to receive enough votes to get sifted up to the front page within 2 days.

*learn

Adding video to channels (Learn) - requested by messenger.

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