Glossary-12
GLOSSARY
SIO: Serial Input/Output. The
electronic methodology used in serial
data transmission.
soft key: Key combinations that
emulate keys on the IBM keyboard,
change some configuration options,
stop program execution, and access
the numeric keypad overlay.
software: The set of programs,
procedures and related documentation
associated with a computer system.
Specifically refers to computer
programs that direct and control the
computer system’s activities. See
also hardware.
stop bit: One or more bits of a byte
that follow the transmitted character
or group codes in asynchronous serial
communications.
subpixel: Three elements, one red,
one green and blue (RGB), that make
up a pixel on the color LCD. The
computer sets subpixels indepen-
dently, each may emit a different
degree of brightness. See also pixel.
synchronous: Having a constant time
interval between successive bits,
characters or events.
system disk: A disk that has been
formatted with an operating system.
For MS-DOS the operating system is
contained in two hidden files and the
COMMAND.COM file. You can boot
a computer using a system disk. Also
called an operating system disk.

RGB

RGB: Red, green, and blue. A device
that uses three input signals, each
activating an electron gun for a
primary additive color (red, green, and
blue) or port for using such a device.
See also CRT.
RJ11: A modular telephone jack.
RJ45: A modular LAN jack.
ROM: Read Only Memory: A
nonvolatile memory chip manufac-
tured to contain information that
controls the computer’s basic opera-
tion. You cannot access or change
information stored in ROM.
S
SCSI: Small Computer System
Interface is an industry standard
interface for connection of a variety of
peripheral devices.
SD cards: Secure Digital cards are
flash memory widely used in a variety
of digital devices such as digital
cameras and Personal Digital Assis-
tants.
serial communications: A communi-
cations technique that uses as few as
two interconnecting wires to send bits
one after another.
serial interface: Refers to a type of
information exchange that transmits
information sequentially, one bit at a
time. Contrast: Parallel interface.