1st Generation iPod
The 1st generation iPod is the first iPod model by Apple announced on October 23, 2001, the cost of the original iPod was $399 with a 5 GB hard drive. Critics panned the unit's price, but it proved an instant hit in the marketplace, quickly
overtaking earlier hard drive MP3 players such as the NOMAD Jukebox. In March 2002 Apple announced a 10 GB version priced at $499.
Apple designed a mechanical scroll wheel and outsourced the implementation and development to Synaptics, a firm which also developed the trackpad for Apple's PowerBooks.
The 1st generation iPod featured four buttons (Menu, Play/Pause, Back, and Forward) arranged
around the circumference of the scroll wheel, and one Select button in the center.
2nd Generation iPod
The 2nd generation iPod came in 10 GB and 20 GB capacities and was introduced on July 17, 2002, at Macworld, and the mechanical scroll wheel of the original was replaced with a touch-sensitive, non-mechanical one (manufactured by Synaptics), termed a "touch wheel".
Due to new Toshiba hard drives, the 20 GB iPod slightly exceeded its 1st generation counterpart in thickness and weight, while the 10 GB model was slimmer. It came with a carrying case and wired remote and it was the first one that was compatible with Windows.
In December 2002 Apple released 4 limited-edition, laser-engraved, autographed iPods from Beck, Tony Hawk, Madonna, and No Doubt. They sold for $50 over the normal retail price in each capacity until it was discontinued.
3rd Generation iPod
The 3rd generation iPod featured the four buttons above the touch wheel with "select" in the center and slightly smaller than its predecessors and was introduced by Apple CEO Steve Jobs on April 28, 2003. They had more distinctively beveled edges and Apple produced 10 GB, 15 GB, 20 GB, 30 GB, and 40 GB versions.
These iPods use a 30-pin connector called the Dock Connector (longer and flatter than a FireWire connector). The iPod Dock came bundled with all but the least expensive iPod and also retailed separately. It featured touch-sensitive buttons located between the display and touch wheel. The new buttons featured red backlighting, allowing easier use in darkness.
The touch-sensitive buttons, which was built upon the touch-sensitive scroll wheel introduced in the 2nd generation iPod, makes it unique in that it has no external moving parts (other than the hold slider on the top of the unit) and is the only iPod that doesn't have its buttons surrounding the wheel.
Apple stopped shipping separate Mac and Windows versions of the unit and instead, all iPods were shipped with their hard drives formatted for Macintosh use; they included CD-ROM featuring a Windows utility which could be reformatted for use with a Windows PC.
4th Generation iPod
The 4th generation iPod integrated the four buttons into the scrollwheel and it's considered the model in
which sales greatly increased, thus starting the "iPod Craze". In the most obvious difference from its predecessors, the 4th generation iPod carries over the click-wheel design introduced on the iPod Mini and was introduced in July 2004.
Some users criticized the click wheel because it does not have the backlight that the 3rd generation iPod buttons had, but others noted that having the buttons on the compass points largely removed any need for backlighting.
Apple also claimed that updated software in the new iPod allows it to use the battery more efficiently and increase battery life to 12 hours.
Other minor changes included the addition of a "Shuffle Songs" option on the top-level menu to make it more convenient for users.
After many requests from users asking for these improvements to operate on earlier iPods as well, Apple on February 23, 2005, released a firmware update which brings the new menu items to 1st-3rd generation iPods.
Originally, the 4th generation iPod had a monochrome screen and no photo capabilities, like its predecessors. It came in 20 GB and 40 GB sizes.
In February 2005 Apple discontinued the 40 GB model and began solely selling a monochrome 20 GB version. The monochrome 4th generation iPod, slightly thinner (about one millimeter less) than the 3rd generation iPod, introduced the ability to charge the battery over a USB connection.
5th Generation iPod
The 5th generation iPod is often called the iPod video or the video iPod was released on October 12, 2005 and it's available in 30 GB and 60 GB capacity models. It has the ability to play MPEG-4 and H.264 video with resolutions of up to 480 x 480 (maximum macroblock (16x16 pixel) count of 900) and 320 x 240 (maximum macroblock (16x16 pixel) count of 300), respectively (videos purchased from the iTunes Music Store are limited to 320 x 240).
You can play widescreen resolutions up to 640x360 using MPEG-4 and 400 x 192 using H.264 (total macroblock count falls within the stated maximums).
5th generation models have a 65,536 colour (16-bit) screen, with a 320 x 240 QVGA transflective TFT display, and are able to display video on an external TV via the AV cable accessory, which plugs into the headphone minijack and splits into composite video and audio output connectors with RCA jacks.
It can also display video on an external TV using the iPod AV or S-video cables with the iPod Universal Dock. The dimensions are 103.5 x 61.8 x 11.0 mm for the 30 GB version, and 103.5 x 61.8 x 14.0 mm for the 60 GB version.
The screen size is now 2.5 inches (6.35 cm) diagonally, 0.5 inches (12.7 mm) larger than the previous iPod. It is 30% thinner than the previous full-size iPod. The battery life for the 30 GB is 14 hours and for the 60GB is around 20 hours. Watching movies reduces that amount to 2 and 3 hours respectively.
The click wheel design is the same as the previous generation, but is marginally smaller (1.5" diameter) than before. The new click wheel is completely flat, unlike older models where the center button is slightly rounded and raised.
Apple stopped producing iPods with the click wheels used in the 4th generation iPod and iPod Mini from their previous supplier, Synaptics, and now use an in-house solution.
Like the iPod Nano, the 5th generation iPod comes in two colors, white and black, and it features the World Clock, Stopwatch, and Screen Lock applications.
In addition, the earphone plug is smaller and comes with a thin slip case, most likely in response to many complaints concerning the iPod Nano's easily-scratched surface.
Apple also discontinued the inclusion of an AC adapter and FireWire cable and you must purchase these item separately in order to charge the iPod from a household outlet, or use an external, powered USB hub.
The 5th generation iPod no longer supports file transfers via FireWire, but still supports charging using FireWire. This is most likely due to the increased popularity of Hi-Speed USB 2.0 in the consumer market as well as decreasing manufacturing component costs by lowering the complexity of the circuit boards and removing unnecessary accessories.
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