HP Professional sp750 Compaq Professional Workstation SP750 Hardware Reference - Page 61

SCSI Devices and Guidelines Guidelines for SCSI Devices When installing and operating SCSI devices, you must follow these guidelines: s A single Ultra SCSI, Ultra-Wide SCSI, Wide-Ultra SCSI, Wide Ultra2 SCSI or Ultra3 SCSI, controller allows you to daisy-chain up to 15 additional SCSI devices. Counting the controller, that amounts to 16 total SCSI devices. s If two SCSI controllers are each connected to separate system board SCSI connectors, each controller may have seven SCSI devices attached. This will give a total of 16 SCSI devices on the system. s The SCSI controller requires a unique SCSI ID (0-7 or 8-15) for each SCSI device installed. The controller identifies a SCSI device by its SCSI ID number rather than its location. Moving a SCSI device from one position to another on the SCSI chain does not affect communication between the controller and the device. The reserved and availagle SCSI ID numbers for SCSI devices are: ❏ 0 is reserved for the primary hard drive. ❏ 7 is reserved for the controller. ❏ 1 through 6 and 8 through 15 are available for all other SCSI devices. s If only one SCSI hard drive is used, it should be installed in the lowest numbered bay (bay 1). s On a Compaq Professional Workstation SP750, Bay 4 is reserved for the CD-ROM or DVD-ROM drive. Do not install a SCSI device in this bay. s Every SCSI chain or circuit must be terminated (closed) at both ends. Some system boards have both ends of the SCSI cable connected to, and terminated by, the system board. Termination can be accomplished in one of several ways: ❏ Use a cable with a built-in terminator. ❏ Use a cable with a terminating resistor plug in the last connector. ❏ Connect a SCSI device with its termination enabled into the last connector. C-2 Hard Drive Installation Guidelines