my feet are so heavy so is my head

Posted by Sardonicus @ 2005-12-17 21:36:43 EST

Sadly, that wasn't the case IIRC. The truth is far more disturbing.

I had a document on this topic from one of my journals when CDs were first coming out. It's a big myth that CD players read "pits" as 0's and peaks as 1's. If only it was that rational. What actually happens is that a transition from peak to pit signals a 1. I think it might way work the other way around (pit to peak) too. If I was warm enough to sit down with pencil and paper I could work it out in my head.

One would think it would require 2 bits to constitute a transition to generate a 1. That implies that to store 8 bits (one byte) you would need 16 bits. But they only use 14 its. Maybe the standard always assumes that the first bit-area on a sector is a peak (or untouched) and that any deviation constitutes a transition. So that gets us down to only needing 15 bits. If they make the same assumption about the last bit maybe they can get away with only needing 14 bits to store 8 bits. But I haven't sat down to figure this out to see if it would work.

I don't see wtf they don't just represent bits in a 1-for-1 fashion. The story behind that must be very interesting.
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