Option block

SCSI ID address pins (JP1 - JP4)

68 pin auxiliary connector

This jumper controls how the drive starts when power is applied. If the jumper is NOT installed then the file will spin up automatically after power-on reset. If the jumper IS installed the file will NOT spin up unless the host system issues a 'START UNIT' command to the file.

SCSI terminator on (JP6)

When this jumpers is installed, the on-card SCSI bus terminator is enabled. There is no terminator on the 80-pin model

Unit attention disable (JP7)

When this jumper is installed the drive will not generate a unit attention following a power on reset (POR) or SCSI bus reset. Any pending unit attention conditions will also be cleared at POR or SCSI bus reset.

Enable TI-SDTR/Enable TI-SDTR/WDTR (JP8)

When the jumper is installed the drive will initiate synchronous data transfer speed negotiation (50,68 & 80 pin) and initiate wide data transfer request (68 & 80 pin) following a SCSI bus reset or power on event.

Auto start delay and delay start (JP9,JP10)

The auto start delay and delay start pins control when and how the drive can spin up, with the combination of auto spin up option (JP5).

When in auto spin up and start delay mode the drive start will be delayed by a period of time multiplied by its own SCSI address. If auto spin up is disabled, these jumpers will be ignored.

Disable      Auto      Auto
auto         start     start
spin up      delay     delay
                       6/12
JP5          JP9       JP10      Option
-------------------------------------------------------
on           don't     don't     Drive will NOT spin up
             care      care      requires start command
-------------------------------------------------------
off          off       off       Spin up immediately
                                 after POR
-------------------------------------------------------
off          on        off       Spin up six seconds
                                 multiplied by SCSI
                                 address after POR
-------------------------------------------------------
off          on        on        Spin up twelve seconds
                                 multiplied by SCSI
                                 address after POR
-------------------------------------------------------

When this jumper is installed, the drive's SCSI parity checking is disabled.

External activity (LED) pins (JP12)

The LED pins can be used to drive an external light emitting diode. Up to 8mA of sink current capability is provided. The LED anode must be tied to the current limited +5V source provided on pin # 1 of the option jumper block. The LED cathode is then connected to the pin # 2 to complete the circuit.

Default setting

The default jumper setting at shipment is as follows.
Jumpers installed on 50 and 68 pin models.

          JP2 & JP3  SCSI address #6
          JP6        SCSI terminator enabled

SCSI signal connector

The SCSI signal connector is a 50 pin connector meeting the ANSI SCSI specification. The SCSI SCA-80 pin connector conforms to SFF 8046.

Note: It is intended that the hard disk drive should only be in electrical contact with the chassis of the system at a designated set of mounting holes. Other electrical contact may degrade error rate performance. As a result of this it is recommended the mounting holes or the side rails into which the mounting holes are tapped.