Seagate ST9144 manual Drive configuration

8 ST9144 Family Installation Guide, Rev. B

Drive configuration

∙Master/Slave configuration. Refer to the table below to con- figure up to two drives on a single AT bus.

System Configuration	Pins A-B	Pins C-D
Drive is Master, no Slave present	Removed	Removed
Drive is Master,	Removed	Installed
Seagate Slave present*
Drive is Slave to another	Installed	Removed
ST9144 Family AT Drive
Reserved Positions (Do Not Use)	Installed	Installed

*Includes ST125A, ST138A, ST157A, ST1102A, ST1144A, ST351A, ST3096A, ST3120A, ST3144A, ST9051A, ST9052A, ST9077A, ST9096A, and ST9144A.

∙Power connection. The ST9144 family drives use +5 Volts DC power supplied to the drive through the interface connector. Refer to the “44-Pin AT Interface Connector Assign- ment” table for specific pin assignments.

Caution. The drive does not use +12 Volts DC power. Make sure only +5 Volts DC is being supplied to the drive, as specified in the “44-Pin AT Interface Connector Assignment” table.

∙Attach AT interface cable. Use a 44-pin AT interface connec- tor cable with two rows of 22 female contacts on 0.079 inch (2 mm) centers. Pin 20 has been removed on the connector for keying purposes. A dual-drive system requires a 44-pin AT interface daisy-chain cable. Most cables have a stripe down one side to designate Pin 1.

Make sure Pin 1 on the interface cable connector is aligned to Pin 1 on the drive interface connector and Pin 1 on the host connector. The maximum cable length is 18 inches (457 mm).