Asus TS300-PA4 - Manual (Page 46)

Chapter 2: Hardware setup 2-26
SATA backplane jumper settings and HDD ID assignments
The 6-pin jumper J3 allows you to define your desired SATA configuration. The
picture below shows the location of jumper J3 with pins 1-3 and 2-4 shorted.
Refer to the table for the jumper settings
and the appropriate ID# for each SATA
HDD bay.
J3 setting
(1-3 shorted, 2-4 shorted)
Device SATA ID#
Drive Bay 1 ID0
Drive Bay 2 ID1
Drive Bay 3 ID2
Drive Bay 4 ID3