LSI 8751D User Manual
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Glossary of Terms and Abbreviations
Configuration
Refers to the way a computer is set up; the combined hardware
components (computer, monitor, keyboard, and peripheral devices) that
make up a computer system; or the software settings that allow the
hardware components to communicate with each other.
CPU
Central Processing Unit. The “brain” of the computer that performs the
actual computations. The term Microprocessor Unit (MPU) is also used.
DMA
Direct Memory Access.
DMA Bus
Master
A feature that allows a peripheral to control the flow of data to and from
system memory by blocks, as opposed to PIO (Programmed I/O) where
the processor is in control and the flow is by byte.
Device Driver
A program that allows a microprocessor (through the operating system)
to direct the operation of a peripheral device.
Differential SCSI
A hardware configuration for connecting SCSI devices. It uses a pair of
lines for each signal transfer (as opposed to single-ended SCSI which
references each SCSI signal to a common ground). Two types of
differential signals in the industry are High Voltage Differential (HVD) and
Low Voltage Differential (LVD).
Dword
A double word is a group of four consecutive bytes or characters that are
stored, addressed, transmitted, and operated on as a unit. The lower two
address bits of the least significant byte must equal zero in order to be
Dword aligned.
EEPROM
Electronically Erasable Programmable Read Only Memory. A memory
chip typically used to store configuration information. See NVRAM.
EISA
Extended Industry Standard Architecture. An extension of the 16-bit ISA
bus standard. It allows devices to perform 32-bit data transfers.
External SCSI
Device
A SCSI device installed outside the computer cabinet. These devices are
connected in a continuous chain using specific types of shielded cables.
Fast-20
The SCSI Trade Association (STA) supports the use of “Ultra SCSI” over
the term “Fast-20”. Please see Ultra SCSI.
Fast-40
The SCSI trade association (STA) supports the use of “Ultra2 SCSI” over
the term “Fast-40”. Please see Ultra2 SCSI.