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

A feature that allows a peripheral to control the flow of data to and from

Master

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

A SCSI device installed outside the computer cabinet. These devices are

Device

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.

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Glossary of Terms and Abbreviations