IBM 220, Hardware Maintenance Manual

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Installing options
91
SCSI port
The server has an integrated small computer system interface (SCSI) controller with
an internal connector (J41) on the system board. This controller supports an Ultra160
SCSI internal channel. This channel supports up to 15 SCSI devices. In addition, this
controller uses:
• Double-transition clocking to achieve high transfer rates
• Domain name validation to negotiate compatible data transfer speeds with each
device
• Cyclic-redundancy checking (CRC), instead of the usual parity checking, to
significantly improve data reliability
• An active terminator on the system board for SCSI bus termination
If you install a SCSI adapter in the server, you can use its SCSI connector to connect
different types of small computer system interface (SCSI) devices.
Note: If you install a PCI redundant array of independent disks (RAID) adapter, you
can move the SCSI cable from the system-board SCSI connector to an internal
channel connector on the RAID adapter if you want to control the internal
drives from the adapter.
SCSI cabling requirements
A SCSI cable comes with the server so that you can connect internal SCSI devices to
the SCSI controller on the system board. A 2-drop SCSI cable comes with the models
that have the hot-swap drive cage option. A 5-drop SCSI cable comes with the models
that have the standard non-hot-swap drive cage. If you plan to use the SCSI cable to
connect internal SCSI devices to another SCSI or ServeRAID controller (for example,
an optional PCI adapter), you must purchase and install an optional SCSI cable to
connect other SCSI devices (for example, a tape drive) to the SCSI connector on the
system board. If you plan to attach external SCSI devices, you must install an optional
SCSI adapter and order additional SCSI cables.
For information about the maximum length of SCSI cable between the terminated
ends of the cable, refer to the ANSI SCSI standards. Adhering to these standards will
help ensure that the server operates properly.
Setting SCSI IDs
Each SCSI device that is connected to a SCSI controller or adapter must have a unique
SCSI ID. This ID enables the SCSI controller or adapter 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.
To install external SCSI devices, you must first install an optional SCSI PCI adapter.
Refer to the information that is provided with the device for instructions to set its SCSI
ID.
4 Not connected 9 PIN 14 Vertical synchronization
(Vsync)
5 Digital return 10 Digital return 15 DDC SCL
Pin Signal Pin Signal Pin Signal
Table 14. Video-port connector pin-number assignments.