Cronyms, Bbreviations – SimpleTech Zeus Ultra User Manual

Page 39

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Acronyms and Abbreviations

Zeus Ultra DMA Solid State Drives

33

A

CRONYMS

AND

A

BBREVIATIONS

A

ARM (Advanced RISC Machine) <processor> (ARM,
Originally Acorn RISC Machine). A series of low-

cost, power-efficient 32-bit RISC microprocessors for
embedded control, computing, digital signal
processing, games, consumer multimedia and

portable applications.
ATA (AT Attachment) The IDE interface is officially

known as the ATA specification. ATA-2 (Fast ATA)
defined the faster transfer rates used in Enhanced
IDE (EIDE). ATA-3 added interface improvements,

including the ability to report potential problems (see
S.M.A.R.T.). Starting with ATA-4, either the word
“Ultra” or the transfer rate was added to the name in

various combinations. For example, at 33 MBytes/
sec, terms such as Ultra ATA and ATA-33 have been
used. In addition, Ultra ATA-33, DMA-33 and Ultra

DMA-33 are also found.

C

CFA (Computer Fraud and Abuse Act of 1986) The
CFA was a significant step forward in criminalizing

unauthorized access to computer systems and
networks. The Act applies to “federal interest
computers” which include systems used by the U.S.

government, as well as most financial institutions.
The Act makes unauthorized penetration or other
damage to such systems a felony.
CHS Cylinder, Head, Sector A disc-drive system and
method for generating logical zones that each have
an approximate number of spare sectors, and that

are used to translate logical block addresses.
CISC (Complex Instruction Set Computer)
Pronounced “sisk.” The traditional architecture of a

computer which uses microcode to execute very
comprehensive instructions. Instructions may be
variable in length and use all addressing modes,

requiring complex circuitry to decode them.

D

DMA (Direct Memory Access) Specialized circuitry
or a dedicated microprocessor that transfers data

from memory to memory without using the CPU.
Although DMA may periodically steal cycles from the
CPU, data are transferred much faster than using the

CPU for every byte of transfer.
DoD (Department of Defense) The military branch of

the U.S. government, which is under the direction of
the Secretary of Defense, the primary defense policy
adviser to the President.
DSL (Digital Subscriber Line) A technology that
dramatically increases the digital capacity of ordinary
telephone lines (the local loops) into the home or

office. DSL speeds are tied to the distance between
the customer and the telco central office (CO). DSL
is geared to two types of usage. Asymmetric DSL

(ADSL) is for Internet access, where fast
downstream is required, but slow upstream is
acceptable. Symmetric DSL (SDSL, HDSL, etc.) is

designed for short haul connections that require high
speed in both directions.
DSLAM (DSL Access Multiplexer) A central office
(CO) device for ADSL service that combines voice
traffic and DSL traffic onto a customer's DSL line. It

also separates incoming phone and data signals and
directs them onto the appropriate carriers network.

E

EDC/ECC (Error Detection Code/Error Correction
Code) A memory system that tests for and corrects

errors automatically, very often without the operating
system being aware of it. When writing the data into
memory, ECC circuitry generates checksums from

the binary sequences in the bytes and stores them in
an additional seven bits of memory for 32-bit data
paths or eight bits for 64-bit paths. When data are

retrieved from memory, the checksum is recomputed
to determine if any data bits have been corrupted.
Such systems can typically detect and automatically

correct errors of one bit per word and can detect, but
not correct, errors greater than one bit.

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