Apple fixes Thunderbolt target disk mode in software updateApple on Thursday released a software update for its Thunderbolt firmware for Mac, adding a stability fix for Mac owners using the fast I/O protocol in Target Disk Mode.
The new Thunderbolt firmware version 1.2 comes over five months after Apple released v1.1, which fixed an issue causing some MacBook Pros to see malfunctions when using Thunderbolt cables with a bus-powered device.
From the release notes:
About Thunderbolt Firmware Update v1.2
This update provides stability fixes for Thunderbolt and Target Disk Mode.
When your computer restarts a gray screen will appear with a status bar to indicate the progress of the update.
Do not disturb or shut off the power on your computer during this update. Note: Your computer must be plugged into AC power for the update to install.
The latest Thunderbolt firmware comes in at 1.22MB and requires OS X Lion 10.8.3 or later to run. Users can download the update via Software Update or Apple's Support website.