Seagate CHEETAH 9 ST19101N/W/WC/WD/DC - Manual (Page 50)

48 Cheetah 9 Installation Guide, Rev. B
WC/DC drives
WC/DC drives section Setting the SCSI ID jumpers
The SCSI ID for “WC” and “DC” model drives is normally set
over the SCSI bus by the host system using connector contacts
39 (ID0), 40 (ID2), 79 (ID1), and 80 (ID3).
Terminating the drive
“WC” and “DC” model drives do not have internal terminators or
any other way of adding internal termination to the drive. You
must provide external termination to these drives when termina-
tion is required.