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Internet Control Message Protocol, a protocol primarily for testing and error message.

ISA configuration utility. A configuration database utility that stores most popular ISA cards' configuration including the valid IRQs, DMAs, I/O addresses and memory addressed.   It's just like the ECU for EISA bus system, the ICU will report the resources conflicts before users insert their ISA adapter.

IDE (Integrated Drive Electronics)
Integrated Drive Electronics. One type of hard drive specification for IBM PC and compatible computers, also used in some Macintoshes.  A hard disk technology that puts the communication control and related circuitry on the drive itself (integrated). Older technologies such as MFM had some of the electronics on the  drive and the rest on the interface card. See also EIDE.

Institute of Electrical and Electronics Engineers. An organization that promotes electrical and electronics standards. For more information you can visit

IEEE 1394
Called Firewire by Apple, IEEE 1394 is a serial bus that runs at 100/200/400 Mbit/sec and doesn't require any terminators. A special feature of IEEE 1394 is isochronous transfer mode. For more information you can visit

A measure of a material's resistance to the transfer of electricity.

Incremental Multisession
Incremental Multisession uses pointers in each session to link all the sessions together. These links enable you to access the latest information, starting from the last session on a disc.

A device that is in control of the bus and sends commands to a target.

Maker of the 80x86 and Pentium lines of processors which are used in IBM PC and compatible computers.

Part of a computer, program, or peripheral that communicates with other components. Interface also refers to the user interface.

Internal SCSI Device
A SCSI device installed inside the computer cabinet. These devices are connected in a continuous chain using an unshielded ribbon cable.

The world's leading computer netwwork. The name comes from the concept of routing, seen as an Interconnection of Networks.

On IBM PC and compatible computers. A signal that a device sends to the computer when the device is ready to accept or send information. See interrupt request (IRQ).

Interrupt Request
On IBM PC and compatible computers. Hardware lines over which devices can send interrupts. Typically each device connected to the computer uses a separate IRQ. It is a good idea to know which IRQ each device on your computer is using (the IRQ for the mouse and keyboard should be found in your manuals). Expansion cards such as Ethernet cards or token ring adapters also use IRQs. Setting the IRQ so that it does not conflict with (use the same IRQ as) other devices is an essential part of installing expansion cards and new devices.


I/O Address
Locations within the input/output address space of an IBM PC or compatible computer used by a device, such as a printer or modem. The address is used for communication between software and the device.

Internet Protocol - the basic protocol on the Internet.

Infrared, the most potential wireless media, is more and more popular for today's modern mobile or portable applications. Because there were many incompatible IR systems in the market, the IrDA standard was released in summer 1994 and is now having more than 70 members and companies including HP, IBM, Intel, Microsoft, Apple to support this standard. The transfer rate of the irDA is 115.2kbps maximum now, and higher speed (1.15& 4Mbps) standards are scheduled to be reached.

Interrupt Request Channel. A signal used by devices to indicate that thy need attention from the CPU.  Computers have several IRQ channels so that many devices can be attached, each one to its own IRQ, and serviced by the CPU.

Industry Standard Architecture. An 8-bit computer bus introduced by IBM(International Business Machines) in 1983 and later expanded to 16-bit for the IBM AT computer.  The ISA bus is also known as the AT bus.

ISA Plug and Play
The introduction of the Plug-and-Play ISA specification on May 28, 1993, a joint development by Intel and Microsoft, alters the way expansion boards work in conjunction with the bus.  Plug-and-Play ISA is designed to give ISA systems the same, if not better, self-configuration capabilities enjoyed by more recent expansion bus designs. In fully compliant systems, you can plug in any combination of expansion boards and never have to worry about such things as DIP switch settings, jumper positions, interrupts, DMA channels, ports, or ROM ranges. Each Plug-and-Play ISA card can tell its computer host exactly what resource it requires. If the resource requests of two or more cards conflict, the Plug-and-Play system automatically straightens things out.

Plug and play acts as a configuration technician inside your computer, it actually takes over and handles configuration process internally. It automatically assigns resources such as IRQs, I/O addresses and DMA channels. This makes installing add-on cards simple, eliminating the trial-and error guesswork.

See Scatter/Gather. Hardware Integrated Scatter/Gather Engine. The SCSI feature of Scatter/Gather were implemented by hardware and integrated into the SCSI controller, this will minimizes interrupts and transfer overhead (without CPU intervention).

The International Standards Organization.

Isochronous transfer
A method of sending data that guarantees that the data will arrive at its destination at a specified period of time. Isochronous transfers are important for sending data such as video and audio, since they are dependent on time.

ISO 9660
File layout standard (formerly called High Sierra).  The ISO-9660 file system format is a standard CD format that lets you read CD-R discs on many platforms.  The names of files and directories that you plan to write to the CD-R disc should be ISO-9660 compliant; otherwise, you may not be able to read the CD from non-DOS systems. ISO-9660 compliant names may include any uppercase character from A to Z, digit from 0 to 9, and underscores symbol ( _ ).

Each ISO-9660 file system includes a set of information referred to as the primary volume descriptor which provides information about the files stored on the CD.  The primary volume descriptor includes the following identifiers and fields :

Volume set identifier - provides a volume name just as a volume name identifies a
set of books. The volume set identifier is used by the primary volume descriptor
only; it's different than the label displayed by the DOS DIR command.

Publisher identifier - names the publisher of the information.

Preparer identifier - names the author of the information.

Application identifier - specifies the application that understands the files on
the CD.

Copyright file name field - names the file that contains copyright information.

Bibliographic field - names the file that contains bibliographic information.

Abstract file name field - names the file that contains an abstract for the

ISO 9660 Format
An internationally accepted standard specifying the logical format for files and directories on a CD-ROM. The steandard allows different computers with different operating systems to access the same data format.

ISO 9660 Image
Or CD-ROM image, image, disc image. A single large file which is an exact representation of the whole set of data and programs as it will appear on a CD, in terms of both content and logical format.

ISO 9660 Interchange Levels
These are three methods of recording and naming files on disc under the ISO 9660 standard. There are three nested, downward-compatible Levels.   In Level 1 (the most restrictive):

Each file must be written on disc as a single, continuous stream of bytes --files may not be  fragmented or interleaved. A filename may not contain more than eight d-characters. A Filename Extension may not contain more than three d-characters. A directory name may not contain more than eight d-characters. 

In Level 2, again, each file must be written on disc as a single, continuous stream of bytes. In Level 3 there are no restrictions.

International Standard Recording Code. Some recorders allow the ISRC to be recorded for each audio track on a disc. The code is made up of: Country Code (2 ASCIIcharacters), Owner Code (3 ASCII characters), Year of Recording (2 digits), Serial Number (5 digits).


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