An iPod is basically a Firewire (or USB in the case of newer units) hard drive. Only the latest versions of the iPod are USB-only; 3rd and 4th generation units support both, and the oldest ones are Firewire-only. If you've got the Windows version, it's formatted with the FAT32 file system, if you have the Mac version, it's formatted to HFS+. So you'll need hardware the supports either Firewire or USB, and a Linux kernel that both supports your chosen interface and has read/write support for the appropriate filesystem. FAT32 is no problem; HFS+ requires something relatively recent.
The music player portion of the iPod is all in a directory called iPod_Control (in the Mac version; I assume it is similar in the Windows edition but don't have a way of checking). Inside here is a binary file iPodPrefs, and directories Device, Music, and iTunes. Device contains two files, a binary file Preferneces that presumably contains your iPod settings, and a SysInfo file that contains hardware data in ASCII text. Music contains a series of sub-folders named F??, each of which contain the actual music (.mp3, .aac, .mp4, .m4p, etc.), presumably based on some sort of hash algorithm. Finally, the iTunes directory contains a set of binary files that contain the iTunes playlists and databases, and mapping data that connects these playlists to the music files in Music/F??/.
You can extract all of the music from an iPod by mounting it and copying Music/*/* to some other location. Loading music in is harder, since the files in iTunes/ need to be updated. You will need an application that understands the iTunes playlist and database file formats, since these can't be readily hand-edited. There is at least one GUI application for doing so - see gtkpod.sourceforge.net for more information.
There *is* a version of iTunes for Mac OS 9, but as I recall the last OS 9 edition was iTunes 2.x; I think this version supports iPods, but probably doesn't support the iTunes Music Store (and therefore can't transfer songs from the Music Store to an iPod because of the DRM issues involved). I don't know where you could download a copy - perhaps VersionTracker could help, but I doubt it's available from Apple's site.
(no subject)
The music player portion of the iPod is all in a directory called iPod_Control (in the Mac version; I assume it is similar in the Windows edition but don't have a way of checking). Inside here is a binary file iPodPrefs, and directories Device, Music, and iTunes. Device contains two files, a binary file Preferneces that presumably contains your iPod settings, and a SysInfo file that contains hardware data in ASCII text. Music contains a series of sub-folders named F??, each of which contain the actual music (.mp3, .aac, .mp4, .m4p, etc.), presumably based on some sort of hash algorithm. Finally, the iTunes directory contains a set of binary files that contain the iTunes playlists and databases, and mapping data that connects these playlists to the music files in Music/F??/.
You can extract all of the music from an iPod by mounting it and copying Music/*/* to some other location. Loading music in is harder, since the files in iTunes/ need to be updated. You will need an application that understands the iTunes playlist and database file formats, since these can't be readily hand-edited. There is at least one GUI application for doing so - see gtkpod.sourceforge.net for more information.
There *is* a version of iTunes for Mac OS 9, but as I recall the last OS 9 edition was iTunes 2.x; I think this version supports iPods, but probably doesn't support the iTunes Music Store (and therefore can't transfer songs from the Music Store to an iPod because of the DRM issues involved). I don't know where you could download a copy - perhaps VersionTracker could help, but I doubt it's available from Apple's site.