Epson EQUITY 386SX/16 PLUS - Manual (Page 122)

Both the diskette drive and hard disk drive sockets are
located on the main system board on the left side of the
subassembly, as shown below.
diskette
drive socket
hard disk
drive socket
subassembly - - E l -
Both sockets have a notch on one side. Connect the
diskette drive cable first. As shown below, there is a tab
on one side of the connector.
diskette drive connector
-tab
diskette drive socket
notch
5-38 Installing and Removing Options