SCSI Disk Jumpiter Definitions (IBM)

DS - Delay Spin

At power on or reset the drive motor starts to spin automatically and the drive prepares itself to perform read or write operations. With the Spin Delay feature enabled, at power on or reset the host [SCSI adapter] must send a START/STOP UNIT command to activate the drive motor for read or write operations. Spin Delay allows the drive to perform power sequencing to prevent an overload of the system power supply due to simultaneous, peak start-up current demands from multiple devices.

EP - Enable Parity

When enabled the drive generates parity information and performs parity checking of data across the SCSI bus. When disabled, parity information is still generated but not checked.

J13 - Termination Power

When enabled this jumper supplies +5vdc termination power from the drive to the SCSI bus. With this jumper removed the SCSI bus must supply termination power. This jumper was used in place of the Term Power jumper on earlier model drives that supported Term Power as an option. At the factory, Quantum configures the disk drive with the J13 jumper enabled; that is, with a jumper installed across the pins labeled J13. To disable Termination Power supply from the disk drive, remove the jumper across the pins labeled J13.

PF - Program Flash

This jumper is used on drives which support flash programming of drive firmware. This feature is found on early models only. This is not used in the field and should be open, ignore this jumper.

SCSI-Bus Device Identification

Used in combination, the jumper settings across the SCSI ID reference pins determine the disk drive's SCSI-bus device I.D.

SD - Spin Delay

At power on or reset the drive motor starts to spin automatically and the drive prepares itself to perform read or write operations. With the Spin Delay feature enabled, at power on or reset the host [SCSI adapter] must send a START/STOP UNIT command to activate the drive motor for read or write operations. Spin Delay allows the drive to perform power sequencing to prevent an overload of the system power supply due to simultaneous, peak start-up current demands from multiple devices.

SS - Self Seek

With the Self Seek jumper enabled the drive performs, at power on, a continuous seek diagnostic. This diagnostic will not terminate until: 1) Power is removed, 2) SS jumper removed. This feature performs no other function on the drive and should not be used.

SY - Spindle Sync

Used with disk drives that support synchronized spindle operation. Master or slave synchronized operation is set through a SCSI Mode Select Page. When the drive operates as a Master drive, it generates a spindle synchronization reference signal. When operating as a slave, the drive synchronizes its spindle according to the input reference. The drive always maintains local speed regulation when no reference signal is applied.

TE - Termination Enable

One of the requirements of the SCSI bus is that it be properly terminated. If more than one SCSI device is connected to the host, only the last device must be terminated. The Terminator Enable (TE) jumper, when installed, enables an active termination circuit, thereby terminating the SCSI bus. With the TE jumper removed, bus termination is disabled.

At the factory, Quantum configures the disk drive with termination enabled; that is, with a jumper installed across the termination pins on the corresponding jumper. To disable termination, the jumper must be removed.

TP - Termination Power

The Termination Power (TP) jumper, when installed, enables termination power to be provided by the disk drive. At the factory, Quantum configures the disk drive with termination power enabled; that is, with a jumper installed across the termination power pins on the corresponding jumper. To disable termination power, remove the jumper.

WP - Write Protect

This feature, when present, is used to enable write protection on the drive. Installing the WP jumper disables the write feature to the drive and makes the device read only. At the factory, Quantum configures the disk drive with the WP jumper disabled.

WS - Wait Spin

At power on or reset the drive motor starts to spin automatically and the drive prepares itself to perform read or write operations. With the Wait Spin feature enabled, at power on or reset the host [SCSI adapter] must send a START/STOP UNIT command to activate the drive motor for read or write operations. Wait Spin allows the drive to perform power sequencing to prevent an overload of the system power supply due to simultaneous, peak start-up current demands from multiple devices.