IBM 3151 Manual To Operations page 144

local mode. A mode in which communications
with the host system are disabled.
LTA. Line. turnaround character.
main port. A port that is used to communicate
with the host system.
modem. (1)
*
(modulator-demodulator) A device
that modulates and demodulates signals
transmitted over data communication facilities.
(2) (TC97) A functional unit that modulates and
demodulates signals. One of the functions of a
modem is to enable digital data to be transmitted
over analog transmission facilities.
null character (NUL). (ISO) A control character
that is used to accomplish media-fill or time-fill,
and that may be inserted into or removed from, a
sequence of characters without affecting the
meaning of the sequence; however, the control of
equipment or the format may be affected by this
character.
numeric keypad. A set of keys, located at the
right side of the keyboard, that can be used to
enter numbers and line-drawing symbols.
NVM. Non-volatile memory.
Glossary
OIA. Operator information area.
online. Pertaining to a user's access to a
computer via a terminal or to terminal
equipm~nt
connected to a transmission line in direct
communication action over the line with another
terminal or with a computer.
operator information area. The Screen area on the
bottom line of the screen where messages are
displayed to define the status of the terminal or
system to the operator.
operator message. A message, displayed in the
operator information area, that informs an
operator of the operating status of the IBM 3151.
option. See setup parameter.
optional device. A device that is connected to the
auxiliary port.
pacing. A'technique by which a receiving station
controls the rate of transmission of a sending
station to prevent overrun.
page.
*
A block of data. The IBM· 3151 allows
only one page to be contained in each partition,
therefore, a partition and a page represent the
same thing. See partition.
parameter. (1)
*
(ISO) A variable that is given a
constant value for a specified application and that
may denote the application. (2) A variable that is
Glossary
X-5