Operating instructions

LUNs (logical unit numbers) A specialized SCSI configuration that allows for
multiple devices to share a single SCSI ID. This type of arrangement is found
most commonly in high-end servers that have large hard disk arrays.
LVD (low voltage differential) A type of differential SCSI. LVD SCSI requires
less power than HVD and is compatible with existing SE SCSI controllers and
devices. LVD devices can sense the type of SCSI and then work accordingly. If
you plug an LVD device into an SE chain, it will act as an SE device. If you plug
an LVD device into LVD, it will run as LVD. LVD SCSI chains can be up to 12
meters in length.
Mac Also Macintosh. Apple Computers’ flagship operating system, cur
-
rently up to OS X and running on Intel-based hardware.
MAC (Media Access Control) address Unique 48-bit address assigned to
each network card. IEEE assigns blocks of possible addresses to various NIC
manufacturers to help ensure that the address is always unique. The Data Link
layer of the OSI model uses MAC addresses for locating machines.
machine language The binary instruction code that is understood by the CPU.
mass storage Hard drives, CD-ROMs, removable media drives, etc.
math coprocessor Also called math unit or floating-point unit (FPU). A sec-
ondary microprocessor whose function is the handling of floating-point arith-
metic. Although originally a physically separate chip, math coprocessors are
now built into today’s CPUs.
MB (megabyte) 1,048,576 bytes.
MBR (master boot record) A tiny bit of code that takes control of the boot
process from the system BIOS.
MCA (Micro Channel architecture) Expansion bus architecture developed
by IBM as the (unsuccessful) successor to ISA. MCA had a full 32-bit design as
well as being self-configuring.
MCC (memory controller chip) The chip that handles memory requests from
the CPU. Although once a special chip, it has been integrated into the chipset on
all PCs today.
GLOSSARY 41
Passport / Mike Meyers‘ A+ Certification Passport / Meyers / 226308-3 / Glossary
P:\010Comp\Passport\308-3\gloss.vp
Monday, April 09, 2007 10:24:45 PM
Color profile: Generic CMYK printer profile
Composite Default screen