Device Termination

SCSI logic requires that termination be enabled for the two devices at opposite ends of the SCSI chain and disabled for all devices in between. However, because both SCSI controllers are self-terminating and because all internal SCSI cables provided by Dell have active termination at the end of the cables, any SCSI devices you install should have termination disabled on the devices.

Furthermore, when attaching external SCSI devices, you should use only external SCSI cables with active termination on the cable at one end. When used with this type of cable, all external SCSI devices also need to have termination disabled on the devices and be connected toward termination.

See the documentation provided with any optional SCSI device you purchase for information on disabling termination on the device.

SCSI Cables

The 68-pin (internal) SCSI cable in your Precision 610 system connects SCSI devices (normally SCSI hard-disk drives) to the 7890 Ultra2/Wide LVD controller.

The connector at the end of the cable attaches to the Ultra2/Wide LVD primary SCSI controller connector labeled "SCSI_ULTRA2" on the system board.

The other connectors on the cable are used for attaching up to four SCSI hard-disk drives in the internal drive bays (see Figure 10-14).

The 50-pin (internal) Narrow SCSI cable connects SCSI devices to the 7880 Ultra/Wide controller.

The narrow connector at the end of the cable attaches to the secondary SCSI controller connector labeled "SCSI_NARROW" on the system board.

The other connectors on the cable are used for attaching SCSI devices installed in the externally accessible drive bays (see Figure 10-14).

An optional shielded external cable with a 68-pin connector is used for attaching an external SCSI device to the 7880 external SCSI connector on the system back panel.

Refer to the documentation that came with the external SCSI device for information on how to connect the device, set its SCSI ID, and disable termination.

Figure 10-14. Internal SCSI Cable

General Procedure for Installing SCSI Devices

Configure and install one or more SCSI devices in your computer as follows:

1.Determine which connector on the internal SCSI cable you will attach to each SCSI device. See "SCSI Configuration Guidelines" found earlier in this section.

2.Unpack each SCSI device and prepare it for installation.

CAUTIONS: Ground yourself by touching an unpainted metal surface on the back of the computer.

When you unpack the drive, do not set it on a hard surface, which may damage the drive. Instead, set the drive on a