This appendix contains the following sections:
If your Silicon Graphics 320 visual workstation has a SCSI PCI option card installed, you can attach external SCSI devices to the system. Here are some tips to keep in mind when attaching SCSI devices:
You can mix Ultra and Fast devices on the same bus. You can also mix 16-bit and 8-bit devices on the same bus. The overall performance of a mixed bus can vary widely.
To daisy-chain a mix of wide and narrow devices, place the wide devices (as a group) closest to the Silicon Graphics 320 workstation where the bus is wide, and place the narrow devices (as a group) at the end of the chain.
Note: Be sure to use an adapter or other special cable that terminates the upper half of the SCSI bus when converting from the final wide device to the first narrow device. Silicon Graphics supplied cables have this integrated into the cable, but not all third-party cables have the terminator integrated into the cable. Unsupported devices may not work with the Silicon Graphics 320 workstation and may cause problems with supported devices.
To attach SCSI devices:
Assign a unique SCSI ID number to each device. Set an ID by moving the jumpers, switch, or dial on the device to the assigned number. You can assign any numbers from 0 to 15, excluding number 7, which is reserved for the SCSI PCI option card.
If you have internal SCSI hard drives installed, the system drive must be set to SCSI ID 0.
If you already have external devices attached and want to add a device, you can check the SCSI ID numbers of the current devices by doing the following:
Select Start > Control Panels from the Windows NT task bar.
Double-click the SCSI Adapters icon to open the SCSI Adapters panel.
Click the + next to PCI SCSI Card to see a list of the devices.
Click a device name, then click the Properties button to open the device Properties panel.
Click the Settings tab. The assigned SCSI ID number for the device appears next to the Target ID label.
Shut down the system and turn off the power. For detailed instructions, see “Shutting Down the System”.
Attach the device to the SCSI connector on the back of the system.
If you are attaching multiple devices, chain them together using the cables that shipped with the devices, making sure not to exceed the maximum cable length of 3 meters. If all devices are Ultra2 SCSI, the maximum cable length is 12 meters.
Caution: Using a cable without controlled impedance may cause your device to not function. For any external device, it is extremely important that you use a cable of controlled impedance which meets Ultra SCSI cable specifications. Not all cables with the correct connector work. This is particularly important if you have more than one external device. Terminate the last device in the chain with an LVD/SE terminator.
Power on the system. For detailed instructions, see “Turning On the System”.
Use the SCSI Adapters panel to verify that the system recognizes the devices you installed.
Select Start > Control Panels.
Double-click the SCSI Adapters icon.
Click the + next to PCI SCSI Card to see a list of installed SCSI devices.
If the system does not recognize one or more of the devices:
Make sure each device is set to a unique SCSI ID number.
Check all the cable connections and verify the last device is terminated. Shut down and reboot the system.
If the system still does not recognize a device, shut down and open up the system. Check to make sure the SCSI PCI card is installed correctly (see “Installing a PCI Card”). If you have internal SCSI hard drives installed, make sure the internal SCSI cable is securely attached to the drives and to the card (see “Attaching the SCSI PCI Option Card Internal Cable”).
Close and reboot the system. If the system still does not recognize the device, there may be a problem with one of the devices, one of the cables, the terminator, or the PCI card. Contact your support representative.