sells individual songs relatively easily and cheaply the typical rates being US$0.99, EU€0.99, or GB£0.79 per song. iPods and specially licensed Motorola mobile phones are the only portable music players that can play the purchased music. The store became the market leader a few years after its launch [verification needed] and Apple announced the sale of videos through the iTunes Store on 12 October 2005. Full-length movies became available from 12 September 2006. [2] Purchased audio files use the AAC format with added encryption. The encryption is based on the controversial FairPlay digital rights management (DRM) system. Up to five authorized computers and an unlimited number of iPods can play the files. Burning the files onto an audio CD removes the DRM, at a cost of reduced quality when re-compressed from one lossy format to another. iPods cannot play music files from other competing music stores such as Napster or MSN Music which use rival DRM technologies like Microsoft's protected WMA or RealNetworks' Helix DRM. RealNetworks claims that Apple is creating problems for itself, [3] by using FairPlay to lock users into using the iTunes Store. Steve Jobs has stated that Apple makes very little profit from song sales, but Apple uses the store to promote iPod sales. [4] [edit] File storage All iPods can function as mass storage devices to store data files. If the iPod is formatted on a Mac OS X computer it uses the HFS Plus file system format. If it is formatted on Windows, the FAT32 format is used because Windows cannot access HFS filesystems. The user must still use iTunes or a compatible third-party software to load audio, videos, and photos in such a way that they are playable and viewable on the iPod. Unlike most MP3 players, simply copying files to the drive will not allow the iPod to properly access them, however, with the use of open-source software, it is possible. An iPod formatted as HFS Plus is able to serve as a boot disk for a Mac computer, allowing one to have a portable operating system installed. The older iPods with FireWire ports could additionally function in FireWire Disk Mode. With the advent of the Windows-compatible iPod, the iPod's default file system was switched from HFS Plus to FAT32, although they could be reformatted to either filesystem (excluding the iPod shuffle which is strictly FAT32). iTunes cannot transfer songs or videos from device to computer, unless they were purchased from the iTunes Store and authorized for use on that computer [citation needed] . The media files are stored in a hidden folder together with a proprietary database on the iPod. While the hidden content can be accessed through the host operating system, practical recovery of the audio with correct file names, tag meta-data, and playlists requires the use of third- party software. [edit] Additional features iPods also have limited PDA-like functionality and can display text files. Contacts and schedules can be viewed and synchronized with the host computer using either iSync, iTunes, Apple Mail, iCal, Outlook or Outlook Express. The larger models have some built-in games such as Brick, Parachute, Solitaire and Music Quiz. Brick was originally invented by Apple co-founder Steve Wozniak in the 1970s. A firmware update released in September 2006 brought several new features to 5th generation iPods including downloadable games, adjustable screen brightness, and rudimentary gapless playback. [edit] Open-source alternatives The iPodLinux project has ported an ARM version of the Linux kernel alongside an interface called "Podzilla" to run on all the iPods, although only the first, second and third generations are "officially" supported by the developers. The project is under continual development with new features popping up all the time. The iPod Shuffle will never be supported because Shuffles are based on a different architecture. An open-source firmware called Rockbox allows the iPod nano, mini, and all iPods after the 3 rd generation to play Ogg Vorbis, FLAC, Musepack, Wavpack, Shorten, MP1, MP2 and MIDI files, but not FairPlay-encrypted files from the iTunes Store. Rockbox also offers gapless playback and a more sophisticated equalizer but is in a testing stage as of September 2006. [edit] Connectivity Originally, a FireWire connection to the host computer was used to update songs or recharge the battery. The battery could also be charged with a power adapter that was included with the first 4 generations. The 3 rd generation included a dock connector allowing for FireWire or USB connectivity, although the device could not be charged via USB. The USB connectivity provided better compatibility with PCs, as most of them did not have FireWire ports at the time. The FireWire cables were nonetheless needed to connect to the AC adaptor. The dock connector also brought an opportunity to exchange data, sound and power with an iPod, which ultimately created a large market of accessories, manufactured by third parties such as Belkin and Griffin. The 4 th generation iPod allowed recharging via USB and eventually Apple started shipping iPods with USB cables instead of FireWire. Later generations dropped support for FireWire entirely. The iPod Nano and Shuffle never supported FireWire, while FireWire support was finally dropped entirely from the product line with the launch of the USB-only 5th generation iPod. The transition from FireWire to USB meant that older Macs were limited to slow data transfers, since FireWire was a standard feature on Apple Macs for many years, while USB 2.0 support was only added in October 2003. Previously, all Macs had USB 1.1 ports, which have a transfer speed of 12 Mbit/s, as opposed to FireWire's 400 Mbit/s or USB 2.0's 480 Mbit/s. [edit] Chipsets and electronics Some electronic components used in iPods Model Storage medium Microcontroller Audio chip iPod 1G, 2G, 3G 1.8 inch (46 mm) ATA hard drives (with proprietary connectors), made by Toshiba. Two ARM 7TDMI- derived CPUs running at 90 MHz. Various audio codecs manufactured by Wolfson Microelectronics iPod 4G, 5G Variable speed ARM 7TDMI CPUs, running at a peak of 80 MHz to save battery life. iPod mini 1G, 2G 1 inch Microdrives manufactured by Hitachi iPod nano 1G Flash memory from Samsung, Toshiba and others 2 ARM 7TDMI CPUs @ 80 MHz iPod nano 2G Flash memory from Samsung, Toshiba and others An Apple-branded ARM CPU [It's believed that these CPUs are from Samsung] An Apple-branded Sound chip [Appears to be from Samsung, as the CPU] iPod shuffle Flash memory SigmaTel STMP3550 chip that handles both the music decoding and the audio circuitry. [5] Each iPod has a 1 MB or 512 KB NOR flash ROM chip which contains a bootloader — a program that tells the device to load its operating system from its storage medium. Each iPod also has 32 MB of RAM, although the 60 and 80 GB 5 th generation have 64 MB. A portion of the RAM is used to hold the iPod OS loaded from firmware, but the majority of it serves to cache songs loaded from the storage medium. For example, an iPod could spin its hard disk up once and copy about 30 MB of upcoming songs into RAM, thus save power by not having the drive spin up for each song. The current iPod models use internal lithium-ion batteries batteries. The 1 st and 2 nd generations used lithium polymer batteries. The larger models use touch wheels provided by Synaptics. On April 26, 2006, EE Times reported that Samsung Electronics had won the contract to provide the media processor for a future model iPod, replacing Apple's previous design supplier PortalPlayer. [6] [edit] iPod models Apple has released different iPod models with different designs, colors, and storage capacities. Information about the current and discontinued models are available on Apple's website. [7] Model (and generation) Image Capacity Changes introduced Connection Original Release date Launch price (US$) iPod 1G 5, 10 GB First release. Wheel physically rotates and buttons are not part of wheel. FireWire 23 October 2001 $399, $499 . cannot transfer songs or videos from device to computer, unless they were purchased from the iTunes Store and authorized for use on that computer [citation needed] . The media files are stored. and others 2 ARM 7TDMI CPUs @ 80 MHz iPod nano 2G Flash memory from Samsung, Toshiba and others An Apple-branded ARM CPU [It's believed that these CPUs are from Samsung] An. Toshiba. Two ARM 7TDMI- derived CPUs running at 90 MHz. Various audio codecs manufactured by Wolfson Microelectronics iPod 4G, 5G Variable speed ARM 7TDMI CPUs, running at a peak of 80