Single Connector Attachment (SCA)

There are two different versions of the connector:

• SCA-1: Outmoded; used a regular 68-pin data connector, 4-pin power connector and several configuration jumpers on a hard disk
• SCA-2: Currently in use; has a single unified 80-pin connector with hot plugging

There are also two types of the SCA, which are single-ended (SE) and low voltage differential (LVD), that run at very high speeds over inexpensive twisted-pair copper cables.

The SCA uses the SCSI standards consisting of a standard port between peripheral devices and the computer. Although many SCSI connector types use separate cables, the SCA connects the drives directly into the system. Only one connector is used for power and data input/output (I/O) as well as signaling as opposed to using two cables for power and data with specific parameters to be set using jumpers on every drive. Likewise, the SCA allows the drives to configure parameters from the SCSI backplane.