your computer has an integrated scsi controller. this dual-channel controller supports two independent, ultra320 scsi channels that support up to 15 scsi devices each. the scsi connectors for the channels are on the system board. the controller has the following features:

    1 double-transition clocking to achieve up to 320 mbps (megabytes per second) data-transfer rates

    2 domain name validation to negotiate compatible data-transfer speeds with each device

    3 cyclic-redundancy checking (crc) to improve data reliability

    4 an active terminator for scsi bus termination

    the following illustration shows a scsi connector.

   

    scsi cabling requirements

    you can install four internal scsi devices using the scsi signal cable that comes with some computer models. if you plan to attach external scsi devices, you can order an additional scsi cable, remove the scsi knockout from the rear of the computer, and connect the new cable from the scsi channel b connector on 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. see “system-board internal connectors” on page 36 for the locations of the scsi connectors.

    if you want to attach external scsi devices to the computer without using the internal scsi channel b, you must install an optional scsi adapter.

    setting scsi ids

    each scsi device that is 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 comes with the device for instructions for setting its scsi id.