Multitech MMH900 User Manual page 189

of a graphical document and, therefore,
cannot be accurately interpreted according to
any character code.
Firmware: A category of memory chips that
hold their content without electrical power,
they include ROM, PROM, EPROM and
EEPROM technologies. Firmware becomes
"hard software" when holding program code.
Flash Memory: A memory chip that holds its
content without power, but must be erased in
bulk. The term comes from its ability to be
erased "in a flash". Flash memory is derived
from EEPROM, but are less expensive and
provide higher bit densities.
Flow control: The process of regulating the
speed at which data enters or leaves a serial
port. Software flow control is implemented by
communications software or by the user
sending predefined characters or packets
which are recognized as "pause" and
"resume" indicators. Hardware flow control is
achieved by using the RTS (request to send)
and the CTS (clear to send) control lines of
the RS232 interface.
G
H
(LAP-M) 256 characters (MNP)
The factory default
setting is &BS1.
being sent and received are accurately
interpreted. With software, an interface is a
module created to be "written to". That is, if
two programs are written to the same
interface, then they can be successfully linked
together.
I
Initialize
Interface
IRQ Level (Interrupt Request Level): The
notification a processor receives when
another portion of the computer's hardware
requires its attention. IRQs are numbered so
that the device issuing the IRQ can be
identified, and so IRQs can be prioritized.
J
K
Kilobit: One thousand bits. A unit of
measure for digital data rates.
Kilobyte: One thousand bytes. A unit of
measure for digital data rates. Not to be
confused with "K", which stands for z
of storage space, either in memory or on disk.
1K of disk space is actually 1024 bytes, 16K is
65,536 bytes and 1M (meg) is 1,048,576
bytes.
L
Leased Line: A private, dedicated communi-
cations channel that connects two locations.
This connection lasts for the duration of the
subscription. Leased lines may be condi-
tioned to improve line quality over that of dial-
up lines.
Line Conditioning: An additional cost option
offered by the telephone company for their
leased, voice-grade lines. The service
provides a careful balance of line enhance-
ments to improve the frequency response and
to reduce distortion.
LRC (Longitudinal Redundancy Check):
Error checking method that generates a parity
bit from a specified string of bits on a
longitudinal track. In a row and column format
such as on magnetic tape, LRC is often used
with VRC, which creates a parity bit for each
character.
M
Mainframe: A large, powerful computer used
to centralize a data processing environment. It
has hundreds of gigabytes of disk storage
space. It uses a front end processor to
connect directly to the communications
channels that interconnect terminals and
computers.
Megabyte: One million bytes when describ-
ing a data rate. 1M of disk space may
actually mean 1,048,576 bytes.
10
bytes