Aaeon SBC-357 Manual page 21

You can attach two Enhanced Integrated Device Electronics hard
disk drives to the SBC-357's internal controller. The card comes
with a 40-pin flat piggyback cable. This cable has three identical
40-pin flat-cable connectors.
Wire number 1 on the cable is red or blue, and the other wires are
gray.
1. Connect one end of the cable to the IDE connector. Make
sure that the red (or blue) wire corresponds to pin 1 on the
connector, which is labeled on the board (on the right side).
2. Plug the other end of the cable to the Enhanced IDE hard
drive, with pin 1 on the cable corresponding to pin 1 on the
hard drive. See your hard drive's documentation for the
location of the connector.
Unlike floppy drives, you can make the connections with any of
the connectors on the cable. If you install two drives, you will
need to set one as the master and one as the slave. You do this
using jumpers on the drives. If you install just one drive, set it as
the master.
Chapter 2 Hardware Configuration 13