Read-Only

Memory from which information can be read but not changed. The contents of ROM are not

Memory (ROM)erased when the computer is turned off.
ReducedThe HP A7173A adapter’s SCSI chips contain a RISC processor.
Instruction Set

 

Computer (RISC)

 

core

 

S

 

SCSI bus

A host bus adapter and one or more SCSI peripherals connected by cables in a linear chain

 

configuration. The host bus adapter can exist anywhere on the chain, allowing connection of

 

both internal and external SCSI devices.
SCSI device

Any device conforming to the SCSI standard that attaches to the SCSI bus by means of a SCSI

 

cable. This includes SCSI host bus adapters and SCSI peripherals.
SCSI ID

A unique identification for each SCSI device on the SCSI bus. Each SCSI bus has fifteen available

 

SCSI IDs numbered 0 through 15 for Wide SCSI or 0-7 for 8-bit SCSI. The host bus adapter is

 

usually assigned ID 7, which gives it priority to control the bus.
SCSI-3

The current SCSI specification that defines the command formats used in the SCSI protocol.

SE

See Single-Ended.
Single-Ended

A hardware specification for connecting SCSI devices. It references each SCSI signal to a common

 

ground, as opposed to differential SCSI and low-voltage differential SCSI, which use a separate

 

return for each signal.
small computer

A specification for a high-performance peripheral bus and command set. The original standard

system interfaceis now referred to as SCSI-1.
(SCSI)

 

SPI-4The SCSI Parallel Interface Specification for ultra320 SCSI componenets.
synchronous data

One of the ways data is transferred over the SCSI bus. Transfers are clocked with fixed-frequency

transferpulses.
system firmware

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

 

system.

T

 

termination

The electrical connection required at each end of the SCSI bus, composed of a set of resistors.

U

 

Ultra SCSI

A standard for SCSI data transfers. It allows a transfer rate of up to 20 MBytes/sec over an 8-bit

 

SCSI bus, and up to 40 MBytes/sec over a 16-bit SCSI bus. The STA (SCSI Trade Association)

 

supports using the term “Ultra SCSI” over the older term “Fast-20.”
Ultra160 SCSI

(Also called Ultra3 SCSI) A standard for SCSI data transfers. It allows a data transfer rate of up

 

to 160 MBytes/second over a 16-bit SCSI bus. The bus width is always 16 bits.
Ultra2 SCSI

A standard for SCSI data transfers. It allows a transfer rate of up to 40 MBytes/sec over an 8-bit

 

SCSI bus, and up to 80 MBytes/sec over a 16-bit SCSI bus. The STA (SCSI Trade Association)

 

supports using the term “Ultra2 SCSI” over the older term “Fast-40.”
Ultra320 SCSI

A standard for SCSI data transfers. It allows a data transfer rate of up to 320 MBytes/second

 

over a 16-bit SCSI bus. The bus width is always 16 bits.

V

 

VCCIVoluntary Control Council for Interference.
VHDCIVery High Density Cable Interconnect.

80 Glossary