US Robotics COURIER HST User'smanual page 119

COURIER HST
Protocol
RAM
Remote Echo
ROM
Serial
Transmission
Start/Stop Bits
Synchronous
Transmission
Terminal
Terminal Mode
G-6
character even or odd, depending on which type of parity
is used.
A system of rules and procedures governing communications
between two or more devices. Protocols vary, but communi-
cating 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 handling are only a few
of the operations defined in a protocol.
Random Access Memory. Memory that is available for use
when the modem is turned on and clears of all information
when the power is turned off. The Courier HST's RAM
holds the current operational settings, a flow control buffer,
and a command buffer.
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.
Read Only Memory. Permanent memory, not user-program-
mable. The Courier HST's factory settings are stored in
ROM and can be read (loaded) into RAM as an operational
configuration.
The transfer of data characters one bit at a time, sequen-
tially, using a single electrical path.
:>-
See Parallel
Transmission.
The signaling bits attached to a character before the charac-
ter is transmitted during Asynchronous Transmission.
A form of transmission in which groups of data bits are
sent at regular intervals. Because the timing is uniform,
no Start or Stop bits are required.
:>-
See Asynchronous
Transmission.
A device whose keyboard and display are used for sending
and receiving data over a communications link. Differs
from a microcomputer in that it has no internal processing
capabilities. Used to enter data into or retrieve processed
data from a system or network.
An operational mode required for microcomputers to trans-
mit data. In Terminal Mode the computer acts as if it were
a standard terminal such as a teletypewriter, rather than a
data processor. Keyboard entries go directly to the modem,
whether the entry is a modem command or data to be