Q: What is the hareware in an iPod?

A: The iPod video uses a 30-GB Toshiba 1.8-inch hard drive (model MK3008GAL), featuring 4200 rpm and a USB interface. It weighs 1.7 ounces (48 grams) and fits 30 GB onto a single platter, squeezing in 93.5 gigabits per square inch. To fit so much into so little space, the drive uses smaller and lighter sliders (which keep the right spacing between the read/write heads and the recording surface) and a more sensitive thin-film technology on the heads and the platter. The increased sensitivity allows for a greater number of recorded bits per square inch.

The display is a 2.5-inch, 16-bit, TFT LCD. It has a 320x240-pixel resolution and a 0.156 dot pitch. The screen is incredibly thin -- just 0.125 inches (3.175 mm) deep. The connectors used in the iPod are miniscule. Instead of the plastic connectors you find in larger devices, the ends of the wires that connect the various components of the iPod are coated in a film that stiffens them to create a viable input. Here you can see where the LCD connects to the back side of the motherboard (with a U.S. dime for reference):

In the image above, you can see the Click Wheel controller. A "mixed-signal array" is a chip that can deal with both analog and digital data. In the case of the Click Wheel, the controller has to accept analog data generated by the movement of a finger over the surface of the wheel and turn it into digital data the microprocessor can understand. Let's find out how it does that.

iPod's battery is completely built-in -- you can't just pop in a couple of new AA batteries when it stops charging. This built-in battery has been a headache both for iPod owners and for Apple. Originally, the iPod battery was not only non-user-replaceable, but it was also very expensive to replace via Apple. When your battery died (sometimes within a year of buying the iPod), you had to send your iPod to Apple for a replacement, and the new battery cost $100. A lot of bad press and a class-action lawsuit later, Apple's iPod battery-replacement program costs $59. The class-action suit was settled, and iPod owners listed in the suit were compensated with $50 vouchers and partial refunds for their $100 battery replacement.