LSI Ultra320 Host, SCSI, Device, Device, SCSI ID, SCSI Bus, Peripheral, SCSI Device, Host Adapter, Single-Ended, Internal SCSI, PCI and PCI-X

Host	The computer system in which a SCSI host adapter is installed. It uses
	the SCSI host adapter to transfer information to and from devices
	attached to the SCSI bus.
Host Adapter	A circuit board or integrated circuit that provides a device connection to
	the host.
Internal SCSI	A SCSI device installed inside the computer cabinet. These devices are
Device	connected to one another with an unshielded ribbon cable.
PCI and PCI-X	Peripheral Component Interconnect. A high performance local bus
	speciﬁcation that allows connection of devices directly to computer
	memory. The PCI Local Bus allows transparent upgrades from a 32-bit
	data path at 33 MHz to a 64-bit data path at 33 MHz; from a 32-bit data
	path at 66 MHz to a 64-bit data path at 66 MHz; and from a 32-bit data
	path at 133 MHz to a 64-bit data path at 133 MHz (1064 Mbytes/s peak).
Peripheral	A piece of hardware (such as a disk drive, printer, or CD-ROM) used with
Device	a computer and under the computer’s control. SCSI peripheral devices
	are controlled through a SCSI host adapter.
SCSI Bus	A host adapter and one or more SCSI devices connected by cables in a
	linear conﬁguration. The host adapter may exist anywhere on the bus,
	allowing connection of both internal and external SCSI devices. A system
	may have more than one SCSI bus by using a multichannel host adapter
	or by using multiple host adapters.
SCSI Device	Any device that conforms to the SCSI standard and is attached to the
	SCSI bus by a SCSI cable. This includes SCSI host adapters, SCSI disk
	drives, SCSI CD-ROMS drives, and so on.
SCSI ID	An identiﬁer that addresses speciﬁc devices on the SCSI bus and
	determines device selection when multiple devices contend for
	ownership of the SCSI bus. Wide SCSI buses support SCSI IDs 0
	through 15, and narrow SCSI buses support SCSI IDs 0 through 7. A
	device gains ownership of the bus according to the priority of its SCSI
	ID. The order of priority, from highest to lowest, is: 7, 6, 5, 4, 3, 2, 1, 0,
	15, 14, 13, 12, 11, 10, 9. The host adapter is usually set to the highest
	priority SCSI ID, which is SCSI ID 7.
Single-Ended	A hardware speciﬁcation for connecting SCSI devices. It references each
SCSI	SCSI signal to a common ground. In contrast, differential SCSI uses a
	separate ground for each signal.

A-2	Glossary of Terms

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