Intel SC450NX Product Guide - Page 97

Peripheral Drives Drive Cabling Considerations This section summarizes device cabling requirements and constraints. The number of devices you can install depends on: • The number supported by the bus • The number of physical drive bays available • The height of drives in the internal bays (1-inch or 1.6-inch high) • The combination of SCSI and IDE devices IDE Requirements An 18-inch long IDE cable that supports two drives is standard in the system. If you install an IDE hard drive, we recommend placing it in the lowest internal drive bay to make cabling easier, particularly if you also have an IDE device in the externally accessible bay. For proper IDE operation, note the cable length specified in Figure 29. If no drives are present on an IDE channel, the cable must be removed. If only one drive is installed, it must be connected at the end of the cable. 12" 6" Baseboard Drive 1 Drive 0 18" Figure 29. IDE Cable Dimensions OM05093  NOTE To disable the IDE controller: If you plan to disable the IDE controller to reuse the interrupt for that controller, you must physically unplug the IDE cable from the board connector if a cable is present. Simply disabling the drive by configuring the SSU option does not make the interrupt available. SCSI Requirements One narrow and two wide SCSI cables are standard in the system. All SCSI devices must be unterminated except the peripheral at the end of the SCSI cable. Hard drives usually provide an active termination, while CD-ROM drives do not. Because we recommend putting hard drives only in the internal bays, this means that you should route the SCSI cable so that the last device on the cable is a hard drive in the internal bay. 97