drive 88 and enables a user to select the address of each drive of expansion stack 28 without having to locate and select jumpers on the disk drive board it also enables the user of a disk drive to easily set the address required without forcing the user to examine the internal workings of a module or computer peripheral system something which is still feared by many in this day of u201c computerization u201d a computer interconnection cable such as a scsi interface cable is attached to connectors j 4 and j 5 as shown in fig4 connectors j 4 and j 5 route the computer signal to disk drive 88 and allow interconnection of one module 30 to additional modules 30 through the use of the second connector a drive activity light omitting diode led d 2 is connected to drive 88 the drive activity led d 2 is activated by drive 88 to indicate to a user when the drive is enabled and data is being accessed or written referring to fig5 the relative locations of power supply 86 fan 90 and the connector and switch assemblies as they are mounted in base 80 is shown disk drive 88 is located in area 100 and is not shown for clarity.