iPhone on multiple computers

The problem is that the iphone & the iPod Touch are in essence small computers. How do you mount a computer on another computer? As a network mount, not like an external hard drive.

However, Apple has implemented neither and the reason is probably pretty simple - do you think Apple really wants your average consumer to have direct access to the iphone or touch when the entire file system is then visible? The older iPods had a firmware that was not accessible via disk mode, hence the difference.

If they did, you're going to have consumers left and right trying to move and change things around. The last thing Apple wants is to have to deal with thousands of people every day crowding into Apple Stores and tying up their support because they decided that all these folders with .app extensions (like MobileMusicPlayer.app) are taking up space for their Spice Girls songs... Grandpa Joe does not need access to the file system where he can accidentally delete stuff.

Apple didn't disable disk mode because it's worthless - 1) it wouldn't support disk mode because of the changes to the operating system and 2) they really don't want people who have no business in a file system messing it up.

The iphone would have to support disk mode to do what you want. Your classic does support disk mode, which is why you can do what you want with that.

"I can connect my 80gig iPod to any of my Macs and move/add/manage media content via iTunes. But with the iPhone I'm limited to one computer."

This is true. You are limited to ONE computer with the iphone.

Maybe Earl is asking about something else. You can sync music to your iPhone from only one computer at a time. If you want to switch to another computer for syncing music, it will erase all the music from the first computer, then add the music from the new computer. So: decide which computer to sync from, then put all the music you want on your iPhone onto THAT computer.

Now you CAN sync music from one computer and calendar from another computer.

I'm curious when this started. Let me tell you my story.

I have an iPhone 3GS. Previously I had an iPod touch and prior to that I had an iPod Video 30gig. I've always managed my music manually, and I've always done it on multiple computers - usually 2: my work and home PC (running windows). EVEN when I got the iPhone 3GS (shortly after it launched.) I was managing my music manually and was able to do it on both PC's. I didn't do any hacks or hex editing or anything to make this work - it just worked. In fact, it worked on my iphone up until just recently. I updated to iOS 4 when it was available. I can't say for sure, but I'm fairly certain I was still able to do manage on multiple computers at that point. When 4.0.1 came out, I updated again. I know that now I can only manage on one computer, even though I have 3 authorized in iTunes.

What is the reason for this - I know it isn't a technical reason - certainly the hardware is capable of it.

If you look at this apple support doc:
http://docs.info.apple.com/article.html?path=iTunesMac/9.2/en/21673.html

It says this:
If you want more precise control over the content you add, or if you want to use your iPod with more than one computer, you can choose to manage your music and video manually. Your iPhone or iPad can be managed with only one computer, even if you manage your content manually.

Why? And why all of the sudden (at least for me?)

This is very inconvenient. I always thought apple products were supposed to "just work" without having to fiddle with them.

To be preciese the limitation is one library rather than one computer. Perhaps at some point you'd copied your library from one of your computers to the other. If so, even if the content of the different copies of the library then changes, they will contain the same LibraryPersistentID and iTunes won't issue warnings when you switch between different copies to manage the content. What you may not have noticed however is that any content manually added from one library will be removed if you update the iPhone or an iPad from another library that doesn't also contain that content. I don't know why Apple introduced this unnecessary restiction but it's nothing to do with disc mode whatever you might read elsewhere... It is however a limitation imposed via iTunes, not the iPhone firmware, as iTunes is in charge of all data transfers between the library and the device. Perhaps one of your libraries got corrupted and was rebuilt with a different, newly generated LibraryPersistentID.

To sync your iPhone using which ever computer you want simply move your entire library out to an external drive and connect to each computer as and when you want to use it. In practice I use SyncToy 2.1 to clone my library at home to a portable drive, take it to work and use SyncToy to clone the library to the local drive. Each computer opens the local copy rather than the one on the external. The upshot is that I have three copies of my library as security against data loss and the freedom to update any of my family's iPods & my iPhone from any of my computers.

tt2

Sorry, meant to mention that SyncToy is a Windows tool, but I've no doubt there are Mac equivalents. All you want is something that can compare two versions of the same set of folders and syncronise additions, updates & deletions in both directions without needing to overwrite all the unchanged files.

tt2

Seriously, this ****** me off. It used to work for me - I don't know if I did something tricky to make it work (if I did it was unintentional.) It is just ridiculous that it works on iPods including the iPod touch, but you can't manage your music from multiple computers on the iPhone. Stupid.

It is a little strange to me that this is only NOW becoming an issue to Apple. I have an iPod Touch, and I can add music from multiple libraries on different computers. So far I have added music from 4 computers onto my iPod Touch, all of which are different libraries with different music files.

Admittedly, I only actually sync the iPod with one laptop. However, the only reason I sync is to update applications.

As far as I can tell, the iPod Touch and the iPhone use, basically, the same operating system. So, why can I feel free to add music, movies and pictures from any computer I wish, while my sister with her iPhone 4 is limited to a single computer?

I highly doubt it has anything to do with allowing people access to the system files, since I am able to manage my iPod Touch with any computer in my household. I also highly doubt it's a security "feature" (are you really going to try arguing that adding data from multiple sources corrupts the drive? Have you never heard of USB drives?).

So, why now? Why all of a sudden? What happened to ease of use? Plug and play? Hotswapping?

I suppose this is the new era of limitations.