Compaq AP500 - Manual (Page 62)

3-42 Removal and Replacement Procedures
SCSI Guidelines for Installing SCSI Devices
■ If you are installing a narrow SCSI device, you will need to attach a 68- to 50-pin SCSI
adapter to the narrow SCSI device.
■ A maximum of seven SCSI devices may be installed on the integrated Wide-Ultra SCSI
controller.
■ A unique SCSI ID (0-6 and 8-15) must be set for each SCSI device installed.
■ Before you install a SCSI device, verify the SCSI ID of the drive, and if necessary, set the
SCSI ID to a unique ID number.
■ The controller identifies a SCSI device by its SCSI ID (SCSI ID 1) number rather than its
bay location (Bay 2). Therefore, moving a SCSI device from one bay location to another
or changing the position of the device on the SCSI chain does not affect the
communication between the controller and the SCSI device.
■ The reserved and available SCSI ID numbers for SCSI devices are as follows:
❏ SCSI ID 0 is reserved for the primary hard drive (bootable drive).
❏ SCSI ID 7 is reserved for the controller.
❏ SCSI IDs 1-6 and 8-15 are available. Do not use IDs 8-15 for narrow devices on the
same SCSI bus.
■ Bay 4 is reserved for the CD-ROM drive. Do not install a SCSI device in this bay.
■ If only one SCSI hard drive is used, it should be installed on the lowest numbered bay
(Bay 1).
■ Every SCSI chain must be terminated (closed) at both ends.
■ SCSI devices may not have terminating jumpers on the device. Determine if the device
ought to have termination enabled or disabled. Set the termination if necessary.
Termination on these devices must be achieved with a non-terminated cable.
■ Turn on an external SCSI device before turning on power to the workstation. This enables
the system board controller to recognize the external SCSI device.
■ When an external SCSI device is connected to the external SCSI connector on the rear
panel of the workstation, that device becomes the end of the SCSI chain and must be
terminated.
■ SCSI drives on the SCSI controller must be either internal or in an external storage
system, but not both.
SCSI Guidelines for Optimizing Performance
■ To maintain Ultra speeds, do not install more than four SCSI devices on a SCSI bus.
■ Do not mix Wide-Ultra and narrow SCSI devices on the same SCSI chain or the same
controller.
For additional information about optional SCSI devices, refer to the documentation included
with the device.