Using FireWire Target Disk Mode
by Jamie Dresser

One of the most under utilized features of FireWire has to be Target Disk Mode. Target Disk Mode is an extremely useful tool that you may only use sporadically, or, if you have a fast desktop Mac and a portable Mac, you may even start hooking your portable up to your desktop to share files on a regular basis. As I personally found out, it's a great last-ditch possibility if the computer you're trying to transfer files to does not have drivers for a FireWire hard drive to be hooked up to it - Target Disk Mode does not require drivers and it's nearly foolproof. A Kinkos in San Francisco learned that when I transferred a critical file to them to print, when all other methods failed. Of course, an internal CD-RW drive would have worked also, but that was not an option unfortunately :>)

Before explaining how to use Target Disk Mode, a little background on FireWire is in order. Apple's Developer site has an excellent page about FireWire and IEE1394, it is located here.

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Using FireWire Target Disk Mode

FireWire target disk mode allows any Macintosh computer with a FireWire port (the target computer) to be used as an external hard disk connected to another computer (the host). Once a target computer is started up as a FireWire hard disk and is available to the host computer, you can copy files to or from that volume.

To Use FireWire Target Disk Mode, your target and host must meet these requirements:

Host computer Requirements:

The Host computer must meet the following requirements:

• FireWire Port, any of the following types:
  • Built in from the factory (such as any system in the following Target Device list)
  • FireWire port via a PC Card in a PowerBook
  • FireWire port via a PCI Card in a Power Macintosh
• FireWire 2.3.3 or later
• Mac OS 8.6 or later

Target Computer Requirements:

The following Apple Macintosh systems can be used as target computers:

• PowerBook (FireWire), aka "Pismo"
• PowerBook G4
• PowerBook G4 (Gigabit Ethernet)
• PowerBook G4 (DVI)

• iBook (FireWire)
• iBook SE (FireWire)
• iBook (Dual USB)
• iBook (Late 2001
• iBook (14.1 LCD)
• iBook (16 VRAM)
• iBook (14.1 LCD 16 VRAM)

• Power Mac G4 (AGP Graphics) with ATA drive
• Power Mac G4 Cube
• Power Mac G4 (Gigabit Ethernet)
• Power Mac G4 (Digital Audio)
• Power Mac G4 (QuickSilver)
• Power Mac G4 (QuickSilver 2002)
• Power Mac G4 (Mirrored Drive Doors)

• eMac

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Using FireWire target disk mode

Very Important! It is advisable to not use any other FireWire storage devices when using FireWire Target Disk Mode. Unmount and Unplug all other FireWire devices from both computers prior to using FireWire target disk mode. Do not plug in any FireWire devices until after you have disconnected the two computers from each other, or have stopped using target disk mode.

Step by step instructions to use FireWire target disk mode:

1. Make sure that the target computer is turned off. If you are using a PowerBook computer or iBook computer as the target computer, you should also plug in its AC power adapter to avoid the battery running out and causing possible data loss.
2. Use a FireWire cable (6-pin to 6-pin) to connect the target computer to a host computer. The host computer does not need to be turned off. Cables are available in lengths from 8" to 10' - if you are going to use FireWire Target Disk Mode frequently, you may find it handy to have a cable already run into position to allow for easy access to your systems.
3. Start up the target computer and immediately press and hold down the T key until the FireWire icon appears on the screen, it will move around, floating on the screen denoting the system is running in FireWire Target Disk Mode. The hard disk of the target computer should become available to the host computer and will appear on desktop. If the target disk's icon does not appear, restart the computer. This only seems to be necessary with Mac OS X 10.2 "Jaguar" and also under Mac OS X 10.2.1.
4. When you are finished copying files, drag the target computer's hard disk icon to the Trash or select Put Away from the File menu (Mac OS 9) or Eject from the File menu (Mac OS X). It is now safe to proceed to step 5.
5. Press the target computer's power button to turn it off.
6. Unplug the FireWire cable. You can now use the Target computer as a standalone system once again.