HP A6828A User Manual download pdf (Page 129)

Glossary 113

Glossary

A

address A speciﬁc location in memory,

designated either numerically or by a

symbolic name.

asynchronous data transfer One of the

ways data is transferred over the SCSI bus.

It is slower than synchronous data transfer.

B

bit A binary digit. The smallest unit of

information a computer uses. The value of a

bit (0 or 1) represents a two-way choice, such

as on or off, true or false.

Boot Console Handler (BCH) Provides,

among other things, the reading and setting

of SCSI parameters without the OS running.

bus A collection of wires in a cable or copper

traces on a circuit board used to transmit

data, status, and control signals. EISA, PCI,

and SCSI are examples of buses.

bus mastering A high-performance way to

transfer data. The host bus adapter controls

the transfer of data directly to and from

system memory without bothering the

computer’s microprocessor. This is the

fastest way for multi-tasking operating

systems to transfer data.

byte A unit of information consisting of

eight bits.

C

central processing unit (CPU) The

“brain” of the computer that performs the

actual computations. The term Micro

Processor Unit (MPU) is also used.

chain A topology in which every device is

connected to two others, except for two-end

devices that are connected to only one other.

Committee, International and Special,

for Protection in Radio (CISPR) An

international committee on radio frequency

interference.

conﬁguration Refers to the way a computer

is set up; the combined hardware

components (computer, monitor, key board,

and peripheral devices) that make up a

computer system; or the software settings

that allow the hardware components to

communicate with each other.

Cyclic Redundancy Check (CRC) 32-bit

scheme (referred to as CRC-32) included in

Ultra160 that ensures complete integrity of

the transferred data. CRC is guaranteed to

detect all single bit errors, any two bits in

error, or any combination of errors within a

single 32-bit range.

D

device driver A program that allows a

microprocessor (through the operating

system) to direct the operation of a

peripheral device.

differential 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).

direct memory access (DMA) A method of

moving data from a storage device directly to

RAM, without using the CPU’s resources.

1 2 ... 124 125 126 127 128 129 130 131 132 133 134 ... 137 138

Comments to this Manuals

No comments