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G
LOSSARY
7-7
checking has been surpassed by more reliable and
efficient forms of error checking, including
V.42
and MNP 2-4 protocols . Either the same type of
parity must be used by two communicating
computers, or both may omit parity.
protocol
A system of rules and procedures governing
communications between two or more devices.
Protocols vary, but communicating devices must
follow the same protocol in order to exchange data.
The format of the data, readiness to receive or send,
error detection and error correction are some of the
operations that may be defined in protocols.
RAM
Random Access Memory. Memory that is available
for use when the modem is turned on, but that
clears of all information when the power is turned
off. The modem's RAM holds the current
operational settings, a
flow control buffer , and a
command buffer .
remote digital loopback
A test that checks the phone link and a remote
modem's transmitter and receiver.
remote echo
A copy of the data received by the remote system,
returned to the sending system, and displayed on
the screen. Remote echoing is a function of the
remote system.
ROM
Read Only Memory. Permanent memory, not user-
programmable.
serial transmission
The consecutive flow of data in a single channel.
Compare to parallel transmissions where data flows
simultaneously in multiple channels.
start/stop bits
The signaling bits attached to a character before
and after the character is transmitted during
asynchronous transmission .
terminal
A device whose keyboard and display are used for
sending and receiving data over a communications
link. Differs from a microcomputer or a mainframe
in that it has little or no internal processing
capabilities.