<P> Target Disk Mode (sometimes referred to as TDM or Target Mode) is a boot mode unique to Macintosh computers . </P> <P> When a Mac that supports Target Disk Mode is started with the' T' key held down, its operating system does not boot . Instead, the Mac's firmware enables its drives to behave as a SCSI, FireWire, Thunderbolt and / or USB - C external mass storage device . </P>

What is target disk mode on a mac