Internet Architecture Board. The coordinating committee for the management of the Internet. They are a group of people responsible for research intot he direction of the Internet and the development of TCP/IP. They also create task forces to research Internet issues. Previously, the abbreviation IAB stood for Internet Activities Board.
IBM Cabling System
IBM has specified a wide variety of cables for its Token-Ring network. The most common cable types follow:
Type1. Includes two data-grade, twisted pairs consisting of solid copper conductors. Both pairs are enclosed by a single shield.
Type2. Includes two solid-conductor, data-grade, twisted pairs enclosed by the same shield. In addition, the cable incorporates two voice-grade cables, enabling the same cable to be used for voice and data.
Type3. An unshielded twisted-pair cable similar to Category 3 UTP. IBM specifications originally limited use of Type3 cable to 4-Mbps token ring.
Type6. Includes two data-grade twisted pairs constructed with stranded wires. The stranded wires make Type6 cables more flexible and, therefore, better suited for cables that frequently are moved. Stranded cables, however, cannot carry signals as far as cables with solid conductors.
See also Token Ring, Twisted Pair Ethernet(10BaseT), UTP, IBM data connector, IBM MSAU, 8228,RI,RO.
Originally, any personal computer compatible with the IBM line of personal computers.
With the launch of IBM's proprietary microchannel architecture in the PS/2 line of computers, which replaced the aT bus, two incompatible standards emerged, and so the term became misleading. Now, it is becoming more common to use the term"industry-standard computer" when referring to a computer that uses the AT or ISA bus, and the term "DOS computer" to describe any PC that runs DOS and is based on one of the Intel family of chips.
IBM data connector
A fairly bulky connector that has several interesting features. When disconnected, it shorts pairs of conductors together, enabling you to disconnect devices from the network without introducing a break into the ring wiring of a token-ring network.
IBM Multistation Access Unit. IBM's Token-Ring cabling uses MSAUs. MSAUs are a type of hub and the more modern ones often have 16 or more ports to which devices can be connected. Each MSAU has two special ports called Ring In(RI) and Ring Out(RO). A ring network is created by connecting the RO port of each MSAU to the RI port of the next MSAU in the ring. Each device on the network is connected to an MSAU by an individual cable. There are relays in the MSAUs that operate to configure the network as a logical ring. These relays normally are closed, permitting signals to flow around the ring. When a device connects to the network, the relay for that station opens, forcing signals to flow out tot he device. The device returns the signal to the MSAU, and the signal continues around the logical ring.
A series of personal computers based on the Intel 8088 processor, introduced by IBM in mid-1981.
The specifications for the IBM PC seem puny in comparison to current computer systems; the PC was released containing 16K of memory, expandable to 64K on the motherboard, and a monochrome video adapter incapable of displaying bit-mapped graphics. The floppy disk drive held 160K of data and programs. There was no hard disk on the original IBM PC; that came later with the release of the IBM PC/XT.
In 1983, IBM released an improved version of the PC, the IBM PC-2, which came with 64K of memory, expandable to 256K on the motherboard, and a double-density floppy disk drive capable of storing 360K fo programs and data. The Color/Graphics Adapter (CGA) and an RGB color monitor were also introduced at the same time.
A series of personal computers based on the Intel 80286 processor, introduced by IBM in 1984.
The AT represented a significant performance increase over previous computers, up to 75 percent faster than the PC/XT, and the AT bus standard is used in many clones or IBM compatible computers.
A series of personal computers based on the Intel 8088 processor, introduced by IBM in 1983.
The PC/XT was the first IBM personal computer to offer a built-in hard disk and the capability to expand memory up to a whopping 640K on the motherboard. The original PC/XT used an Intel8088 running at a clock speed of 4.77 MHz- very slow when compared with today's 66 and 100 MHz clock speeds. (Wow, to think we have clock speeds 800MHz and above now!!!!)
A series of personal computers using several different Intel processors, introduced by IBM in 1987.
The main difference between the PS/2 line and earlier IBM personal computers was a major change to the internal bus. Previous computers used the AT bus, also known as industry-standard architecture, but IBM used the proprietary micro channel architecture in the PS/2 line instead. Micro channel architecture expanison boards will not work in a computer using ISA.
A set of seven or nine separate 32-bit chips used in IBM's line of RISC workstations. With up to 7.4 million transistors depending on configuration, the RS/6000 uses a superscalar design with 4 separate 16K data cache units and an 8K instruction cache. There is a single-chip version called the PowerPC.
A series of innovative and popular notebook computers from IBM
A general name for a family of IBM system components-printers,terminals, and terminal cluster controllers--that can be used with a mainframe computer by an SNA link. Terminal emulation software that emulates a 3270 terminal is available for both DOS and Microsoft Windows, as well as for OS/2.
Integrated Drive Electronics. In 1986, Compaq started work to integrate Western Digital controller technology with Control Data Corporation hard drives, IDE is the result of this work. IDE had several advantages. Besides a power cable, only a single cable was required. More important, however, close integration of controller and hard drive has resulted in dramatic performance improvements, even while drive costs have been plummeting. IDE drives now offer outstanding performance at costs of less than 40 percent per megabyte.
IDE drives do not require an elaborate controller on the motherboard, just a simple, inexpensive interface is all that is required. Virtually all motherboards now have built-in IDE controllers, but inexpensive IDE expansion boards also are available.
A PC can support two IDE controllers, each of which can support two drives. A PC, therefore, can support four IDE drives.IDE drives are excellent for workstations, but poor choices for servers and disk mirroring.
Note:As of 1997, Standard IDE drives allow for only 512 MB of disk space to be accessed without special drivers. This is dure to a 1,024 cylinder limit in the original IDE specification. EIDE allows newer systems to access sizes aboe 512MB on one drive, up to 2 GB.
The International Electrical and Electronics Engineers organization. It is the largest professional organization in the world. The IEEE has a well-established standardization process that is open to a broad range of input. As a result, standards developed by the IEEE generally receive universal industry support. IEEE LAN standards are grouped under the heading 802. A wide variety of 802 standards have been or are in the process of being defined.
A serial protocol that runs at speeds ranging from 100 to 400 megabits per second, depending upon the implementation. Devices that are prime candidates for IEEE 1394 include digital camcorders and VCRs, digital audio amplifiers, and video teleconferencing.
Defines a network layer called the logical link control(LLC) layer.
A web server that comes with BackOffice, which runs on WinNT Server; or in a more limited way on NT Workstation as a Peer Web service. IIS can support 3 different Internet data transfer protocols: FTP,Gopher, and HTTP. It can communicate with data sources to display web pages that are created "on demand." It functions as either as an Internet or intranet service provider, can be configured as a virtual server etc
A large, professional-quality typesetter capable of high-resolution output on paper or film.
An electrical property of a cable that combines capcitance, inductance, and resistance. Impedance can be described as the apparent resistance to the flow of alternating current at a given frequency; mismatches in impedance along a cable cause distortions and reflections.
In terms of data flow, indicates consumption of data. An in pin is compatible with an out pin.
INF file Information file
A file created for a particular adapter that provides the operating system with information required to set up a device, such as a list of valid logical configurations for the device, the names of driver files associated with the device, and so on. An INF file is typically provided on a disk by the device manufacturer or may be included in the operating system.
INI file Initialization file
Commonly used under Windows 3.x and earlier, INI files have been used by both the operating system and individual applications to store persistent settings related to an application, driver, or piece of hardware. In Windows 32-bit operating systems, INI files are supported for backward compatibility, but the registry is the preferred location for storing such settings.
The class of filters that provide an interface for HID hardware, including USB and legacy devices, plus proprietary and other HID hardware, under the WDM HID architecture.
An OpenGL driver model in which the driver is responsible for implementing the entire OpenGL pipeline. Intended for high-end graphics cards that implement most of the OpenGL pipeline in hardware.
A string that distinguishes a device from other devices of the same type on a computer. An instance ID is a string without any path-separator characters that contains serial-number information if supported by the underlying bus or some kind of location information. The format of the string is bus-specific.
In object-oriented programming, to create an instance of a class.
A mechanism for reporting information about the state of PC hardware and software to enable management applications to ascertain and change the state of a PC and to be notified of state changes.
A whole number one in which there is no decimal portion.
Abbreiviated IC. A small semiconductor circuit that contains many electronic components.
Any device--such as a parallel port, graphics adapter, and so on--that is designed on the system board rather than on an expansion card.
Integrated drive electronics Interface
IDE. A popular hard-disk interface standard, used for disks in the range of 40MB to 1.2GB, requiring medium to fast data transfer rates. IDE gets its name from the fact that the clectronic control circuitry needed is actually located on the drive itself, thus eliminating the need for a separate hard-disk controller card.
An international standard-making body, based in Geneva, that establishes global standards for communications and information exchange. ANSI is the U.S. member of ISO.
Abbreviation for internetwork. A set of computer networks, made up of a large number of smaller networks, using different networking protocols.
World's largest computer network.
An IP or domain address which identifies a specific node on the Internet.
Providing a level playing field for incompatible networks to work together.
The process of averaging pixel information when scaling an image. When reducing the size of an image, pixels are averaged to create a single new pixel; when an image is scaled up in size, additional pixels are created by averaging pixels of the smaller image.
IPC. A term that describes all the methods used to pass information between two programs running on the same computer running a multitasking operating system, or between two programs running on a network, including pipes, shared memory queues, the Clipboard,DDE(Dynamic Data Exchange) and OLE (Object Linking and Embedding)
A signal to the processor generated by a device under its control (such as the system clock) that interrupts normal processing.
An interrupt indicates that an event requiring the processor's attention has occurred, causing the processor to suspend and save its current activity, and then branch to an interrupt service routine. This service routine processes the interrupt, whether it was generated by the system clock, a keystroke, or a mouse click; and when it's complete, returns control to the suspended process. In the PC, interrupts are often divided into three classes; internal hardware, external hardware, and software interrupts. The Intel 80x86 family of processors supports 256 prioritized interrupts, of which the first 64 are reserved for use by the system hardware or by DOS.
A chip, used to process and prioritize hardware interrupts. In IBM-compatible computers, the Intel 8259A Programmable Interrupt Controller responds to each hardware interrupt, assigns a priority, and forwards it to the main processor.
Special software invoked when an interrupt occurs. Each type of interrupt, such as a clock tick or a keystroke, is processed by its own specific interrupt handler. A table, called the interrupt vector table, maintains a list of addresses for these specific interrupt handlers.
IRQ. Hardware lines that carry a signal from a device to the processor.
A hardware interrupt signals that an event has taken place that requires the processor's attention, and may come from the keyboard, the I/O ports, or the system's disk drives. In the PC, the main processor does not accept interrupts from hardware devices directly; instead interrupts are routed to an Intel 8259A Programmable Interrupt Controller. This chip responds to each hardware interrupt, assigns a priority, and forwards it to the main processor.
Interrupt vector table
A list of addresses for specific software routines known as interrupt handlers. In a DOS computer, the interrupt vector table conssits of 256 pointers located in the first megabyte of memory.
A network that resembles the Internet but is accessible only within a company or organization.
Novell's network operating system previously known as NetWare. IntranetWare is essentially NetWare 4.01 plus a bunch of added programs designed to make NetWare the ideal server for Internet and Intranet applications.
Input/output control. A custom class of IRPs available to user mode. Each WDM class driver has a set of IOCTLs that it uses to communicate with applications. The IOCTLs give the class driver information about intended usage by applications. The class driver performs all IOCTL parameter validation.
I/O port address
Every I/O device in a computer--including network interface cards(NICs)--must be assigned a unique address.
Internet Protocol. The underlying communications protocol on which the Internet is based. IP allows a data packet to travel across many networks before reaching its final destination. It is one of the two main parts of the TCP/IP protocol suite. Ip delivers TCP and UDP packets across a network. IP works at the network layer. Currently IP is either v4 or v6 (also called IPng). IPv6 also understands IPv4 addresses. IPv4 can not understand IPv6 addresses.
Internet Relay Chat. An Internet client/server application that allows large groups of users to communicate with each other interactively. Specific channels are devoted to one particular topic, from the sacred to the profane, and topics come and go regularly as interest levels change.
I/O request packet. Data structures that drivers use to communicate with each other. The basic method of communication between kernel-mode devices. An IRP is a key data structure for WDM, which features multiple layered drivers.
IRP_MJ_XXX IRP Major
One of a predefined class of IRPs that a device can accept.
Industry-Standard Architecture. The 16-bit bus design was first used in IBM's PC/AT computer in 1984. ISA has a bus speed of 8MHz, and a maximum throughput of 8 megabytes per second. EISA is a 32-bit extension to this standard bus.
Integrated Services Digital Network. A worldwide digital communications network emerging from existing telephone services, intended to replace all current systems with a completely digital transmission system.
Computers and other devices connect to ISDN via simple, standardized interfaces, and when complete, ISDN systems will be capable of transmitting voice, video, music, and data. In other words, its a high-speed digital telephone line for high-speed network communications.
An ISDN terminal adapter, often called an ISDN modem by those not in the know.
Refers to a communication protocol based on time slices rather than handshaking. For example, a process might have 20 percent of total bus bandwidth. During its time slice, the process can stream data.
The Plug and Play process by which cards on an ISA bus are distinguished from each other after system startup
International Standards Organization/Open System Interconnection. In networking, a reference model defined by the ISO that divides computer-to-computer communications into seven connected layers, known as a "protocol stack."
International Telecommunications Union. The United Nations umbrella organization that develops and standardizes ctelecommunications worldwide. The ITU also contains the CCITT, the International Frequency Registration Board (IFRB), and the Consultative Committee on International Radio (CCIR). Popular usage is starting to refer to the CCITT standards as ITU standards.