Personal Computer Maintenance & Service Guide

Compaq Deskpro EP Series of Personal Computers 4-13
When installing additional drives, follow these guidelines:
! For optimal performance, connect hard drives to the primary controller. Connect
expansion devices, such as CD-ROM, IDE tape, and diskette drives to the
secondary controller.
! You may install either a third-height or a half-height drive into a half-height bay.
! You must install guide screws to ensure that the drive lines up correctly in the
drive cage. Compaq has provided extra guide screws, which are installed in the
front of the computer chassis, behind the front bezel. Some options require metric
hardware. Compaq-supplied metric screws are black.
Using the Cable-Select Feature with Ultra ATA Devices
Optional drives are available from Compaq in kits that include a special drive cable. The
configuration of the drives employs a cable-select feature that identifies the drives as
device 0 (primary drive) or device 1 (secondary drive). The system board determines
which drive is device 0 or device 1, based on the way the drives are connected to the
special drive cable. The device 0 drive is the drive connected to the short segment of the
drive cable (or that connector closest to the system board); the device 1 drive is the drive
connected to the long segment of the drive cable.
Drive installation requires no jumper setting changes on the existing or optional drives.
All Compaq drives have the jumpers preset for cable-select installation.
✎
If installing a second device on the primary controller, you must use an
80-conductor Ultra ATA cable for optimal performance. This cable is
available as a Compaq option.