Editing Apple PowerBook cables (section)

=== Using SCSI Disk Mode ===
# Set the PowerBook's SCSI ID in the PowerBook control panel (the Portable control panel on the PowerBook 100). The default is 1. Make sure the PowerBook's disk does not have the same name as the desktop machine's disk.<ref name="til13611" /><ref name="til09301" />
# Shut down the PowerBook, the desktop Macintosh and every other device on the chain. The PowerBook must be shut down, not asleep.<ref name="til09301" />
# Fit the disk adapter to the PowerBook and a terminator to its other end, then connect it to the desktop's SCSI cable or to the last device on the chain. With a Macintosh IIfx, use the black terminator between the adapter and the SCSI system cable. Leave the terminator out when the host is a Macintosh Plus, a Macintosh SE without an internal hard disk or another PowerBook.<ref name="til13611" /><ref name="til09301" /> Apple adds that the terminator may not be needed, and says to remove it and restart both machines if the desktop Macintosh has trouble starting.<ref name="til13611" />
# Switch on the PowerBook. A diamond-shaped SCSI symbol with the ID number moves across its screen.<ref name="til13611" />
# Switch on the desktop Macintosh. The PowerBook's disk appears on its desktop.<ref name="til13611" />
# To finish, shut down the desktop Macintosh, turn off the PowerBook with its power button, turn off any other SCSI devices, and only then disconnect the adapter and the cables.<ref name="til13865">Apple Computer, Tech Info Library article 13865, ''SCSI Disk Mode: Quitting SCSI Disk Mode (11/93)'', [http://absurdengineering.org/library/MASTER%20Tech%20Info%20Library/Macintosh%20Hardware/Macintosh%20PowerBook%20Family/TIL13865%20-%20SCSI%20Disk%20Mode%20-%20Quitting%20SCSI%20Disk%20Mode%20%2811-93%29.pdf absurdengineering.org library]. Correct order for quitting SCSI Disk Mode; adapter left attached; dragging the PowerBook's icon to the Trash can damage directories.</ref>

The ROM checks the battery voltage before it enters disk mode, and it runs the disk-mode code only from a cold start.<ref name="til09301" /> Do not drag the PowerBook's disk icon to the Trash to unmount it. Apple says this can lock up the host and damage the directory of any mounted disk badly enough to need a reformat.<ref name="til13865" />