IBM XT 5160 Technical Reference page 393

mode. (1) A method of operation; for example, the binary
mode, the interpretive mode, the alphanumeric mode. (2) The
most frequent value in the statistical sense.
modeling transformation. Operations on the coordinates of an
object (usually matrix multiplications) that cause the object to be
rotated about any axis, translated (moved without rotating),
and/or scaled (changed in size along any or all dimensions). See
also viewing transformation.
modem (modulator-demodulator). A device that converts serial
(bit by bit) digital signals from a business machine (or data
communication equipment) to analog signals that are suitable for
transmission in a telephone network. The inverse function is also
performed by the modem on reception of analog signals.
modified frequency modulation (MFM). The process of varying
the amplitude and frequency of the 'write' signal. MFM pertains
to the number of bytes of storage that can be stored on the
recording media. The number of bytes is twice the number
contained in the same unit area of recording media at single
density.
modulation. The process by which some characteristic of one
wave (usually high frequency) is varied in accordance with
another wave or signal (usually low frequency). This technique is
used in modems to make business-machine signals compatible
with communication facilities.
modulation rate. The reciprocal of the measure of the shortest
nominal time interval between successive significant instants of
the modulated signal. If this measure is expressed in seconds, the
modulation rate is expressed in baud.
module. ( 1) A program unit that is discrete and identifiable with
respect to compiling, combining with other units, and loading.
(2) A packaged functional hardware unit designed for use with
other components.
modulo check. A calculation performed on values entered into a
system. This calculation is designed to detect errors.
modulo-N check. A check in which an operand is divided by a
number N (the modulus) to generate a remainder (check digit)
Glossary-22