use this connector to connect external scsi devices. the following illustration shows the scsi standard 68-pin, female d-shell scsi connector.
your computer has an integrated scsi controller with raid capabilities. this dual-channel controller supports two independent, ultra320 scsi channels. the scsi connectors for both channels are on the system board. each channel supports up to 15 scsi devices. this controller uses:
1 double-transition clocking to achieve up to 320 mb-per-second data-transfer rates
2 domain name validation to negotiate compatible data-transfer speeds with each device
3 cyclic-redundancy checking (crc), instead of the usual parity checking, to improve data reliability
4 an active terminator for scsi bus termination
scsi cabling requirements
you can install three internal scsi devices using the scsi signal cable that comes with some computer models. if you plan to attach external scsi devices, you must order an additional scsi cable, remove the scsi knockout from the rear of the computer, and connect the new cable from the system board to this opening. to select and order the correct cables for use with external devices, contact your ibm reseller or ibm marketing representative. when using an optional scsi adapter, you must also connect the scsi adapter to the scsi led (j18) connector on the system board receive an indication of scsi hard-disk drive activity. see “system-board internal connectors” on page 29 for the location of the scsi connectors.
setting scsi ids
each scsi device connected to a scsi controller must have a unique scsi id.
this id enables the scsi controller to identify the device and ensure that different devices on the same scsi channel do not attempt to transfer data simultaneously.
scsi devices that are connected to different scsi channels can have duplicate scsi ids. see the information that is provided with the device for instructions about setting its scsi id.