Dell PowerEdge 2500SC User Manual
Page 44

HMA
Abbreviation for high memory area. The first 64 KB of extended memory above 1 MB. A memory manager that conforms to the XMS can make the HMA a direct
extension of conventional memory. See also upper memory area and XMM.
host adapter
A host adapter implements communication between the system's bus and the controller for a peripheral device. (Hard-disk drive controller subsystems include
integrated host adapter circuitry.) To add a SCSI expansion bus to your system, you must install or connect the appropriate host adapter.
HPFS
Abbreviation for the High Performance File System option in the OS/2 and Windows NT operating systems.
Hz
Abbreviation for hertz.
ICES
Abbreviation for Interface-Causing Equipment Standard (in Canada).
ICU
Abbreviation for ISA Configuration Utility.
I/O
Abbreviation for input/output. The keyboard is an input device, and a printer is an output device. In general, I/O activity can be differentiated from computational
activity. For example, when a program sends a document to the printer, it is engaging in output activity; when the program sorts a list of terms, it is engaging in
computational activity.
ID
Abbreviation for identification.
interlacing
A technique for increasing video resolution by only up-dating alternate horizontal lines on the screen. Because interlacing can result in noticeable screen flicker, most
users prefer noninterlaced video adapter resolutions.
internal microprocessor cache
An instruction and data cache built in to the microprocessor. The Intel Pentium microprocessor includes a 16-KB internal cache, which is set up as an 8-KB read-only
instruction cache and an 8-KB read/write data cache.
IPX
Acronym for internetwork packet exchange.
IRQ
Abbreviation for interrupt request. A signal that data is about to be sent to or received by a peripheral device travels by an IRQ line to the microprocessor. Each
peripheral connection must be assigned an IRQ number. For example, the first serial port in your system (COM1) is assigned to IRQ4 by default. Two devices can
share the same IRQ assignment, but you cannot operate both devices simultaneously.
ISA
Acronym for Industry-Standard Architecture. A 16-bit expansion bus design. The expansion-card connectors in an ISA system are also compatible with 8-bit ISA
expansion cards.
ITE
Abbreviation for information technology equipment.
jumper
Jumpers are small blocks on a circuit board with two or more pins emerging from them. Plastic plugs containing a wire fit down over the pins. The wire connects the
pins and creates a circuit. Jumpers provide a simple and reversible method of changing the circuitry in a printed circuit board.
K
Abbreviation for kilo-, indicating 1,000.
KB