PATHHardware Documentation > PowerBook G3 Series 1999

External SCSI Port

The computer has a connector for adding external SCSI devices such as a hard disk drive or a removable media drive. The connector is an HDI-30 high-density 30-pin connector. The signal assignments are listed in Table 3-2 .

Table 3-2 Signals on the HD-30 SCSI connector

Pin	Signal name	Pin	Signal name
1	SCSI_LINK_SEL_L(2)	16	SCSI_DB(6)
2	SCSI_DB(0)	17	GND
3	GND	18	SCSI_DB(7)
4	SCSI_DB(1)	19	DBP_L
5	TERMPWR	20	GND
6	SCSI_DB(2)	21	REQ_L
7	SCSI_DB(3)	22	GND
8	GND	23	BSY_L
9	ACK_L	24	GND
10	GND	25	ATN_L
11	SCSI_DB(4)	26	CXD_L
12	GND	27	RST_L
13	GND	28	MSG_L
14	SCSI_DB(5)	29	SEL_L
15	GND	30	IXO_L

The computer can operate in SCSI disk mode (also called target disk mode) as long as there is a valid system image on the hard disk.