HP 98568A Installation Instruction page 266

HP 7936H/7937H Disk Drives
5. Connect the Power Cord.
Connect the female end of the power cord to the power socket on the back
of the disk drive, and connect the other end to your power outlet.
6. Record the Address.
Make a note that address 0 (or the alternate address you set in an earlier
step of this installation procedure) has been used and is no longer available
on the interface you selected. Use the "Address Record" form on the
Chapter 6, "Mass Storage" tab for this purpose.
6-40 Adding Mass Storage Devices