The external drive bays at the front of your system hold up to three user-accessible, half-height 5.25-inch devices (typically CD-ROM or tape drives). A small computer system interface (SCSI) CD-ROM drive is standard in the first external drive bay, while two additional devices of your choice can be installed in the next two external drive bays. SCSI devices in the external drive bays may be connected to the Ultra/Narrow or Ultra3 (Ultra160) SCSI controller on the system board, or a SCSI controller on an expansion card. A fourth drive bay accommodates a standard 3.5-inch diskette drive, which is controlled by the diskette drive controller on the system board. See Figure 1 for a general view of the various drives, connector cables, and power cables in the external drive bays.
Figure 1. External Drive Bay Hardware
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This section describes how to install the following options:
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NOTE: If you are installing a SCSI hard-disk drive, see "Installing Hard-Disk Drives." |
To remove or install drives in the external bays, you must remove
the computer covers.
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WARNING: Before you perform the procedures in this section, you must turn off the computer and disconnect it from its AC power source. For more information, see "Safety First—For You and Your Computer." |
To protect the inside of the computer from foreign particles, a plastic insert covers each empty external drive bay. Additionally, each empty external drive bay is covered by a metal insert to maintain the necessary electromagnetic interference (EMI) shielding for the chassis. Before you install a drive in an empty bay, you must first remove the plastic and metal inserts. Whenever you remove a drive, be sure to replace the metal insert on the chassis and then replace the plastic insert in the front bezel to cover the empty bay.
To remove the plastic insert for a drive bay that you intend to use, perform the following steps:
To remove the metal insert from a drive bay, perform the following steps:
This section describes the interface cables and power cables used with the drives in your system.
Most interface connectors are keyed for correct insertion; that is, a notch or a raised tab on one connector matches a tab or a notch on the other connector. Keying ensures that the pin-1 wire in the cable goes to the pin-1 ends of the connectors on both ends.
When you disconnect an interface cable, take care to grasp the cable connector, rather than the cable itself, to avoid stress on the cable.
Each drive in the external drive bays must connect to a four-wire DC power cable from the system power supply. The connectors on these cables are labeled "FD1," "FD2," "FD3," "FD4," and "FD5." Connectors FD1 through FD4 are used for 5.25-inch devices; connector FD5 is used for the 3.5-inch diskette drive.
Although SCSI devices are installed essentially the same way as other devices, their configuration requirements are different. To configure SCSI devices installed in the external bays, follow the guidelines in the following subsections.
Each device attached to the Ultra/Narrow SCSI host adapter must have a unique SCSI ID number from 0 to 7.
When SCSI devices are shipped from Dell, the default SCSI ID numbers are assigned as follows:
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NOTE: There is no requirement that SCSI ID numbers be assigned sequentially or that devices be attached to the cable in order by ID number. |
SCSI logic requires that the two devices at opposite ends of the SCSI chain be terminated and that all devices in between be unterminated. The SCSI cable included in your system has an active terminator installed at the end of the cable. Therefore, you should disable the termination on all SCSI devices you attach to this cable.
To install a SCSI device in the external drive bays that uses the integrated Ultra/Narrow SCSI controller, perform the following steps:
NOTICE: See "Protecting Against Electrostatic Discharge."
Ground yourself by touching an unpainted metal surface on the back of the computer, unpack the drive, and compare the jumper and switch settings with those in the drive documentation. (See "SCSI Configuration Information" for information on setting the drive's SCSI ID number and enabling termination [if required].) Change any settings necessary for this system's configuration.
If the drive does not already have drive rails attached, attach a drive rail to each side of the drive and secure each drive rail to the drive with a screw in each of the lower slotted screw holes on the drive rail.
Tape drives, autoloaders, and other SCSI devices that require their own separate controller cards are shipped with the controller card and an interface cable.
To install the tape drive or other device in an external drive bay, perform the following steps:
NOTICE: See "Protecting Against Electrostatic Discharge."
To connect a stand-alone tape drive that connects to the computer using a controller card and shielded interface/power cable, perform the following steps:
NOTICE: See "Protecting Against Electrostatic Discharge."