Specifications

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Appendix A Glossary
mean time between failure See MTBF.
mean time to repair See MTTR.
MEB Stands for Mid-Level Electronics Bay, an SSI
form factor originally developed for use with slot-
based server processors, now used for four-way and
larger designs. Sometimes erroneously referred to as
EEB 3.5.
mebi A multiplier indicating 1,048,576 of a unit
of measurement.
mebibyte (Mi) A unit of information storage
equal to 1,048,576 bytes (1,024×1,024 equals 1Mi).
This value was previously called a binary megabyte.
See also megabyte and kilobyte.
medium The magnetic coating or plating that
covers a disk or tape.
mega A multiplier indicating one million
(1,000,000) of some unit. Abbreviated as m or M.
Traditionally, mega has also been defined as
1,048,576 (1,024 kilobytes, where kilobyte equals
1,024) in applications such as memory sizing and
disk storage (as defined by many BIOSs and by
FDISK and other disk preparation programs). The
term mebi is now used for 1,048,576. See also mebi.
megabyte (MB) A unit of information storage
equal to 1,000,000 bytes. Also called a decimal
megabyte. The value 1,048,576 bytes has been called
a binary megabyte but is now known as a
mebibyte. See also mebibyte.
megapixel A unit of digital camera resolution
equal to approximately 1,000,000 pixels. A 1-
megapixel camera has a resolution of approxi-
mately 1,152×864; a 2-megapixel camera has a
resolution of approximately 1,760×1,168. Finally, a
3-megapixel camera has a resolution of approxi-
mately 2,160×1,440. One-megapixel or lower-
resolution cameras are suitable for 4"×6" or smaller
snapshots only, whereas 2-megapixel cameras pro-
duce excellent 5"×7" enlargements and acceptable
8"×10" enlargements. Three-megapixel or higher-
resolution cameras produce excellent 8"×10" and
11"×14" enlargements. The higher the megapixel
rating, the more flash memory space is used by
each picture and the longer it takes each picture to
be recorded to flash memory.
memory Any component in a computer system
that stores information for future use.
memory caching A service provided by
extremely fast memory chips that keeps copies of
the most recent memory accesses. When the CPU
makes a subsequent access, the value is supplied by
the fast memory rather than by the relatively slow
system memory. L1 and L2 caches are memory
caches found on most recent processors. See also L1
cache, L2 cache, and L3 cache.
memory scrubbing A task performed by many
servers that repeatedly reads memory contents dur-
ing idle time and corrects errors when possible.
Noncorrectable errors are reported to the server
management software so the defective module can
be replaced.
Memory Stick A Sony-developed flash memory
device that’s about the size of a stick of gum. It is
used by digital cameras, camcorders, digital music
players, and voice recorders—primarily those made
by Sony.
memory-resident program A program that
remains in memory after it has been loaded, con-
suming memory that otherwise might be used by
application software.
menu software Utility software that makes a
computer running DOS easier to use by replacing
DOS commands with a series of menu selections.
MESI Short for modified exclusive shared invalid
,
it’s a cache coherency protocol used by Intel
processors.
MFM encoding (modified frequency modula-
tion encoding) A method of encoding data on
the surface of a disk. The coding of a bit of data
varies by the coding of the preceding bit to pre-
serve clocking information. Used only by floppy
drives today because it stores less data than other
types of encoding, such as RLL. See also RLL.
MHz An abbreviation for megahertz, a unit of
measurement indicating the frequency of one mil-
lion cycles per second. One hertz (Hz) is equal to
one cycle per second. Named after Heinrich R.
Hertz, a German physicist who first detected elec-
tromagnetic waves in 1883.
MI/MIC (mode indicate/mode indicate com-
mon) Also called forced or manual originate.
Provided for installations in which equipment
other than the modem does the dialing. In such
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