Dell Precision 420 - Manual (Page 65)

SCSI devices installed by Dell are configured correctly during the manufacturing process. You do not need to set the SCSI ID for these SCSI
devices.
If you attach additional optional SCSI devices, refer to the documentation for each device for information about setting the appropriate SCSI ID
number.
NOTICE: Dell recommends that you use only SCSI cables purchased from Dell. SCSI cables purchased elsewhere are not
guaranteed to work with Dell systems.
Device Termination
SCSI logic requires that either:
l Termination be enabled for the two devices at opposite ends of the SCSI chain and disabled for all devices in between.
l
Termination be enabled at the ends of the cable and disabled on all devices in the chain.
Dell recommends that you use terminated cables and that you disable termination on all devices. See the documentation provided with any
optional SCSI device you purchase for information on disabling termination on the device.
SCSI Cables
Ultra 160/m low-voltage differential (LVD) devices (hard-disk drives) use a 68-pin cable. One end of this cable should be attached to the SCSI
controller connector. The remaining connectors on the cable should be attached to the various LVD devices.
Narrow SCSI devices (tape drives, CD-ROM drives, and some hard-disk drives) use a 50-pin cable. One end of this cable should be attached to
the SCSI controller connector. The remaining connectors on the cable should be attached to the various Narrow SCSI devices.
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.
2. Unpack each SCSI device and prepare it for installation.
NOTICE: Ground yourself by touching an unpainted metal surface on the back of the computer.
NOTICE: When you unpack the drive, do not set it on a hard surface, which may damage the drive. Instead, set the drive on a
surface such as a foam pad that will sufficiently cushion it.
Configure the device for a SCSI ID number and disable termination, if necessary.
3. Install the SCSI devices as appropriate.
l To install a SCSI hard-disk drive, complete steps 3 through 7 of " Installing an EIDE Hard-Disk Drive in the Mini Tower Chassis "
or " Installing an EIDE Hard-Disk Drive in the Desktop Chassis ." Then continue with step 4 of this procedure.
l To install a SCSI tape drive, CD-ROM drive, or DAT drive, complete steps 3 through 7 of " Installing a Diskette, LS-120
SuperDisk, Tape, or CD-ROM Drive in a Mini Tower Chassis " or steps 3 through 6 of " Installing a Diskette, LS-120 SuperDisk,
Tape, or CD-ROM Drive in a Desktop Chassis ." Then continue with step 4 of this procedure.
l To install an external SCSI device, continue with step 4 of this procedure.
l To install a SCSI host adapter card, configure the card and install it in an empty expansion slot (see " Installing an Expansion
Card "). If you attach any SCSI hard-disk drives to the host adapter card, connect the hard-disk drive access cable to the SCSI
host adapter card and to the auxiliary hard-disk drive light-emitting diode (LED) connector on the system board (see Figure 1 in
"Installing System Board Options").
4. Attach the SCSI cable to each SCSI device.
NOTICE: You must match the colored strip on the cable with pin 1 on the drive's interface connector to avoid possible damage
to your system.
The connectors on Narrow SCSI cables are keyed for proper positioning —a raised area on the outside of the header connector fits into a
notch on the device connector. The connectors on LVD SCSI cables are shaped so that they can be attached one way only.
If you are installing an external SCSI device, connect one end of the external SCSI cable to the SCSI bus connector on the back of the
device. Attach the other end of the external SCSI cable to the SCSI connector on the system back panel.
5. Connect the SCSI device(s) to power.
l
If you are installing an internal SCSI device, connect a DC power cable to the power input connector on the SCSI device.
l
If you are installing an external SCSI device, connect the socket end of the power cable into the AC power receptacle on the back