Epson Endeavor - Manual (Page 107)

2. Locate the hard disk drive ribbon cable that came with the
computer. It is a flat cable with three connectors: one on
each end and one in the middle, as shown below.
3. Select the connector on the end of the longest part of the cable
(the main system board connector). Notice the small tab in
the middle of the cable connector, as shown in the
illustration above. Align the connector so that the tab faces
the back of the computer (toward the option slots), as
shown below. (The option card connector board and
diskette drive ribbon cable are removed from the
illustration for clarity.)
3-34 Installing and Removing Drives