CompTIA A+® Complete Deluxe Study Guide:Exams 220-701 (Essentials) and 220-702 (Practical Application)

D

daisy-wheel printer

An impact printer that uses a plastic or metal print mechanism with a different character on the end of each spoke of the wheel. As the print mechanism rotates to the correct letter, a small hammer strikes the character against the ribbon, transferring the image onto the paper.

Data Over Cable Service Internet Specification (DOCSIS)

The standard used by most cable systems for transmitting Internet traffic to a subscriber via television cable.

D channel

The signaling channel of an ISDN circuit; also referred to as the Delta channel.

DDR

A type of SDRAM that doubles the data rate of standard SDRAM by transmitting a single bit on both edges of each FSB clock cycle.

DDR2

A type of SDRAM that uses both edges of each ...