Single Connection Attach SCA Single Connector Attachment <hardware> (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 adaptor and external termination. (http://pcmech.com/show/harddrive/152/). (2003-06-21)