> "Maximum operating altitude: 10,000 feet (3000 m)"
The iPod's hard disc is the reason for the elevation limit.=20
The read/write heads of any hard disc fly over the surface of the
rotating disc, supported on a cushion of air called an air bearing.
Under normal operating conditions, the heads float only a few
nanometers above the surface of the spinning disc.=20
Hard discs used in iPods (and almost all computers) are not sealed.
The air pressure and humidity inside the disc is the same as the
outside air. Since air density decreases with altitude, the higher
you go, the more likely the air bearing will not be able to keep the
head at the proper distance from the disc surface. In the extreme
case, the head will "crash" against the surface of the rotating disc,
destroying the disc.
Does this mean the iPod won't work above 3000 meters? No, it just
means the manufacturer is warning you that the machine is likely to
fail above that elevation. You can help your iPod survive if you
operate it while standing still (to minimize shock).
Flash memory, on the other hand, has no rotating parts, can be used at
any altitude, and is considerably more tolerant of shock, dirt and
high humidity than hard discs are.=20
--oryoki
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