Compaq Deskpro 2000, Service & Reference Manual

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Compaq Service Reference Guide C-1
appendix C
H
ARD
D
RIVES
Device 0/Device 1 Relationship
A device 0/device 1 relationship exists when there are two hard drives connected to a single port.
In this situation, one drive must be designated as the device 0, and the other as the device 1 by the
proper use of the drive jumpers. This designation is necessary because both drives cannot work
simultaneously.
When the computer supports cable-select, the device 0/device 1 designations are determined by
each drive’s connector location on the data cable. Device 0 is attached to the data cable connector
at the farthest distance from the system board while device 1 is attached to the connector closest
to the system board. When only a single drive is used, the drive should be connected to the device
0 connector. The user must set each drive’s jumpers to the cable-select setting for the computer to
properly set the drive designation.
SMART
The SMART IDE and SCSI hard drives for the Compaq Deskpro Personal Computers and
Workstations have built-in drive failure prediction that warns the user or the network
administrator of an impending failure or crash of the hard drive. The SMART drives track fault
prediction and failure indication parameters such as re-allocated sector count, spin retry count,
and calibration retry count. If the drive determines that a failure is imminent, it generates a fault
alert.
Device Cabling
Newer, Ultra ATA-66 (Ultra DMA-66) drives require 40-pin, 80-conductor cables to maintain the
higher data transfer rates possible with the improved technology. The computer system must
support Ultra ATA-66 logic for it to take advantage of the higher data transfer rates.
When using both Ultra ATA-66 and slower Ultra ATA-33 drives in the same system, the drives
will operate at their respective data transfer rates.
Drive Capacities
The combination of the file system and the operating system used in the computer determines the
maximum usable size of a drive partition. A drive partition is the largest segment of a drive that
may be properly accessed by the operating system. A single hard drive may therefore be
subdivided into a number of unique drive partition in order to make use of all of its space.
The table that follows identifies the capabilities and restrictions imposed on the computer by the
combinations of file and operating systems.