MITSUBISHI ELECTRIC MOTHERBOARD DIVISION
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Accelerated Graphics Port (AGP). A bus specification that enables 3-D graphics to display
quickly. The interface uses the computer’s main memory for refreshing the monitor image and to
support the processing required for 3-D image display. When not being used for accelerated
graphics, main memory is restored to use by the operating system or other applications.
ACPI (Advanced Configuration & Power Interface). ACPI defines a flexible and abstract
hardware interface that provides a standard way to integrate power management features
throughout a computer system, including hardware, operating system, and application software.
In addition, ACPI provides a generic system event mechanism for Plug and Play (q.v.) and an
operating-system-independent interface for configuration control. Windows 98 is an example of
an ACPI-aware operating system.
ATAPI (Advanced Technology Attachment Packet Interface). An interface for removable-
media drives. ATAPI is part of the Enhanced Integrated Drive Electronics (EIDE) interface, also
known as ATA-2.
ATX. ATX is an industry-wide open specification for motherboard layout and placement. ATX
improves motherboard design by allowing space for more full-length expansion cards. A double-
height aperture is specified for the rear of the chassis, allowing a greater variety of peripheral
ports. ATX-based computers are also easier to cool.
codec (coder/decoder). In this context, an audio signal analogue-to-digital, digital-to-analogue
coder/decoder.
DIMM (Dual In-line Memory Module). A DIMM is a circuit board containing memory chips
which plugs into a computer’s motherboard by a row of contacts on the DIMM’s lower edge.
DMA (Direct Memory Access). A way of moving data between devices without using the
processor core logic to do it.
DMI (Desktop Management Interface). DMI is an industry-standard interface for keeping
track of and monitoring the status of components in a network of computers.
EIDE (Enhanced Integrated Drive Electronics). A standard electronic interface for mass
storage drives. EIDE’s enhancements to the earlier IDE interface made it possible to address
hard disks larger than 528 Mbytes. EIDE also provides faster access to the hard drive, support
for Direct Memory Access (DMA), and support for removable-media drives (see ATAPI).
ECC (Error Checking & Correcting). A method of detecting — and where possible correcting
automatically — errors in data that is being read or transmitted (in this context, to or from
memory).
EPP/ECP (Enhanced Parallel Port/Extended Capability Port). EPP/ECP is a standard
signalling method for bi-directional parallel communication between a computer and peripheral
devices, that offers the potential for much higher rates of data transfer than the original parallel
signalling methods. EPP is for non-printer peripherals. ECP is for printers and scanners.
EPP/ECP are part of IEEE Standard 1284.
IDE (Integrated Drive Electronics). A standard electronic interface for mass storage limited to
528 Mbytes.
ISA (Industry Standard Architecture). ISA is a standard bus architecture associated with the
original IBM AT motherboard. Although superseded technologically, many expansion cards
continue to use it.
logic-controlled Power Supply Unit (PSU). Also known as a “soft-switch” PSU. A PSU that is
controlled by a combination of firmware/software and which is capable of supplying current to a
+5 V standby rail. Such a PSU facilitates sophisticated power-saving modes, and features such as
