The Free On-line Dictionary of Computing (19 January 2023):

Single Connection Attach
SCA
Single Connector Attachment

    (SCA, "Single Connector Attachment") A non-standard
   type of SCSI connector, used mostly by OEMs, which carries
   both power and data on one 80-pin connector.  SCA SCSI drives
   tend to be cheaper but use with standard SCSI cables requires
   an adapter and external termination.

   (http://pcmech.com/show/harddrive/152/).

   (2003-06-21)