LSI 8751D User Manual

Page 50

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Glossary of Terms and Abbreviations

SCSI Bus

A host adapter and one or more SCSI peripherals connected by cables
in a linear chain configuration. The host adapter may exist anywhere on
the chain, allowing connection of both internal and external SCSI
devices. A system may have more than one SCSI bus 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 and SCSI
peripherals.

SCSI ID

A way to uniquely identify each SCSI device on the SCSI bus. Each
SCSI bus has eight available SCSI IDs numbered 0 through 7 (or 0
through 15 for Wide SCSI). The host adapter usually gets the highest ID,
(7 or 15) giving it priority to control the bus.

SDMS

Storage Device Management System. An LSI Logic software product that
manages SCSI system I/O.

Single-Ended
SCSI

A hardware specification for connecting SCSI devices. It references each
SCSI signal to a common ground. This is the most common method (as
opposed to differential SCSI which uses a separate ground for each
signal).

STA

SCSI Trade Association. A group of companies that cooperate to
promote SCSI parallel interface technology as a viable mainstream I/O
interconnect for commercial computing.

Synchronous
Data Transfer

One of the ways data is transferred over the SCSI bus. Transfers are
clocked with fixed-frequency pulses. This is faster than asynchronous
data transfer. Synchronous data transfers are negotiated between the
SCSI host adapter and each SCSI device.

System BIOS

Controls the low level POST (Power-On Self-Test), and basic operation
of the CPU and computer system.

Ultra SCSI

A standard for SCSI data transfers. It allows a transfer rate of up to
20 Mbytes/s over a 8-bit SCSI bus and up to 40 Mbytes/s over a 16-bit
SCSI bus. STA (SCSI Trade Association) supports using the term “Ultra
SCSI” over the older term “Fast-20”.

Ultra2 SCSI

A standard for SCSI data transfers. It allows a transfer rate of up to
40 Mbytes/s over an 8-bit SCSI bus, and up to 80 Mbytes/s over a

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