Some Power Mac G4 computer configurations come with an Ultra160 Dual Channel SCSI card installed in a PCI slot with one or more internal SCSI hard disks connected to it. You
can install additional internal SCSI hard disk drives, up to a maximum of three drives. It's recommended that you only connect SCSI Ultra160 LVD hard disk drives to the internal port
of the Dual Channel SCSI card.
You can connect external SCSI devices, including older drives with slower data transfer rates, to the external port of the Ultra160 Dual Channel SCSI card.
Because the card has two channels, one connected to the internal port and another connected to the external port, connecting older devices to the external port doesn't slow down the transfer rate of the internal hard disk drives.
Apple recommends that you use only SCSI Ultra160 LVD devices as internal hard disk drives.
To connect older SCSI devices that use a 25-pin or a 50-pin connector-such as Zip drives, scanners, or DAT drives-you need to purchase SCSI adapters, or purchase and install an additional "legacy" SCSI PCI card (one that supports older devices). See document 42667 "
Power Mac G4 (QuickSilver 2002): About the Ultra SCSI PCI Card" for information on the configure-to-order Ultra SCSI card Apple offers.