Epson EQUITY 386/33 PLUS - Manual (Page 100)

Follow these steps to install the hard disk drive in the vertical
mounting position:
1. Place the hard disk drive on the right side of the subassembly
with the mounting plate facing up and the ribbon cable and
power supply sockets facing the back of the subassembly.
cable sockets
2. Locate the hard disk drive ribbon cable that came with your
computer. It is a flat cable with three connectors, one on
each end and one in the middle. (If you are installing a
second hard disk drive, the cable may be attached to the
other drive.)
5-12 Installing and Removing Drives