User Guide

ASUS PCI-SC875 User’s Manual 5
Maximum Cable Lengths
To assure reliable operation, the total length of the SCSI bus, including both internal
and external cabling, should not exceed 6meters (19.7 feet) for synchronous or asyn-
chronous data transfer rates, and 3meters (9.8 feet) for UltraSCSI data transfer rates.
WARNING: This SCSI controller support only single-ended SCSI devices.
Differential SCSI devices may be damaged if you connect them to the SCSI
bus. Read your SCSI device documentation if you are not sure whether a
device is single-ended or differential.
Connecting Internal SCSI Devices
Read the device documentation if you need to physically install a SCSI device in-
side your computer before attaching the cables. To connect internal SCSI devices to
an ASUS PCI-SC875 host adapter, you need the following:
• A 50pin internal SCSI ribbon cable.
• A 68pin internal SCSI ribbon cable.
There must be more connectors in the middle of the cable if you are attaching more
than one internal device. Make sure your cable has enough connectors. To connect
three or more internal SCSI devices to a SCSI bus, make a SCSI ribbon cable that
has enough connectors for all the SCSI devices.
You can connect both 8bit and 16-bit SCSI devices to an ASUS PCI-SC875 host
adapter. To attach 8bit internal devices to a wide SCSI bus, use a 68pin-to-50pin
converter.
You can buy this internal 68pin-to-50pin converter from any cable vendor.
Do not use this converter at the end of the cable; the converter does not provide
termination for the high data byte. To terminate a SCSI bus properly, you must put a
16-bit device at the end of the cable. If a converter with an 8-bit device is at the end
of the cable, the bus does not terminate properly.
To attach a converter, first plug the converter into the SCSI device and then connect
the converter to the internal Wide SCSI ribbon cable.
III. INSTALLATION
III. INSTALLATION
(Internal SCSI)