E
* ECC Memory: Error-Correcting Code Memory
* Edge Device
* EDID: Extended Display Identification Data
* EDO DRAM
* EEPROM: Electrically Erasable Programmable Read-Only Memory
* EGA: Enhanced Graphics Adapter
* EIA-232
* EIA-422
* EIA-423
* EIA-449
* EIA-530
* EIDE: Enhanced IDE
* EISA: Extended Industry Standard Architecture
* ELD: Electroluminescent Display
* ELF Emission
* EM64T: Extended Memory 64-bit Technology
* Embedded System
* Energy Star
* Enhanced Keyboard
* EPLD: Electrically Programmable Logic Device
* EPROM: Erasable Programmable Read-Only Memory
* Erasable Optical Disk
* Error Correcting Memory
* eSATA: External Serial ATA
* Expanded Memory
* Expansion Board
* Expansion Bus
* Expansion Slot
* Extended Memory
* External Bus
* External Data Bus
* External Hard Drive
* External Modem
ECC memory: Error-Correcting Code memory
Error-Correcting Code memory (ECC memory) is a type of memory that includes special circuitry for testing the accuracy of data as it passes in and out of memory. ECC memory is capable of detecting and correcting RAM errors due to environmental influence such as RF interference, power fluctuations, radiation etc.
Edge device
Edge devices are switches, routers, routing switches, IADs and a variety of MAN/WAN devices which are installed in the edge network to pass packets between the access devices and core/backbone network devices. An edge device does not participate in the running of any network layer routing protocol but it obtains forwarding descriptions using the route distribution protocol. It is a physical device using Data Link layer (layer 2) and Network layer (layer 3) technologies.
EDID: Extended Display Identification Data
Extended Display Identification Data (EDID) is a VESA standard data format that contains basic information about a monitor and its capabilities, including vendor information, maximum image size, color characteristics, factory pre-set timings, frequency range limits, and character strings for the monitor name and serial number.
EDO DRAM
Extended Data Out Dynamic Random Access Memory (EDO DRAM) is faster than conventional DRAM, because EDO DRAM can start fetching the next block of memory at the same time that it sends the previous block to the CPU. With EDO, a microprocessor is able to output an address and then change to another address without waiting for the data to come back, be absorbed and then read by the microprocessor, as FPM DRAM requires.
EEPROM: Electrically Erasable Programmable Read-Only Memory
Electrically Erasable Programmable Read-Only Memory (EEPROM), a special type of PROM, is a non-volatile storage chip used in computers and other devices. EEPROM can be erased by exposing it to an electrical charge. Like other types of PROM, EEPROM retains its contents even when the power is turned off.
EGA: Enhanced Graphics Adapter
Enhanced Graphics Adapter (EGA)is an IBM PC display standard with a resolution of 640 x 350 pixels of 16 colours. Introduced in 1984 by IBM for its PC-AT, the EGA card included a 16 kilobyte ROM to extend the system BIOS for additional graphics functions and included the Motorola MC6845 video address generator.
EIA-232
EIA-232, a popular physical layer interface also known as RS-232 or TIA-232, is a standard for serial binary data interconnection between a DTE (Data terminal equipment) and a DCE (Data communication equipment). It is commonly used in computer serial ports. A similar ITU-T standard is V.24.
EIA-422
EIA-422, also known as RS-422 or TIA-422, is the balanced electrical implementation of EIA/TIA-449 for high-speed data transmission. Now referred to collectively with EIA-423 as EIA-530, it provides for data transmission, using balanced or differential signaling, with unidirectional/non-reversible, terminated or non-terminated transmission lines, point-to-point, or multi-drop.
EIA-423
EIA-423, also known as RS-423 or TIA-423, is the unbalanced electrical implementation of EIA/TIA-449 for EIA/TIA-232 compatibility.
EIA-449
EIA-449, also known as RS-449 or TIA-449, specifiecs the functional and mechanical characteristics of the interface between data terminal equipment and data communications equipment. The electrical signalling standards intended for use with RS 449 are RS-422 for balanced signals, and RS-423 for the unbalanced signals, with data rates up to 2,000,000 bits per second. The standard specified two D-subminiature connectors with 37 and 9 pins for the primary and secondary data circuits.
EIA-530
EIA-530, also known as RS-530 or TIA-530, is a balanced serial interface standard that generally uses a 25-pin connector. The specification defines the cable between the DTE and DCE devices. It is a replacement for EIA-449, which uses 37-pin connector. EIA-530 refers to two electrical implementations of EIA/TIA-449: RS-422 for balanced transmission and RS-423 for unbalanced transmission.
EIDE: Enhanced IDE
Enhanced IDE, also called EIDE, is set of extensions devised by Western Digital to the original AT Attachment standard. The name "Enhanced IDE" was presumably selected to build upon the common name for ATA then in popular use: IDE. Enhanced IDE (EIDE) supports data rates of between 4 and 16.6 MBps, about three to four times faster than the old IDE standard. In addition, it can support mass storage devices of up to 8.4 gigabytes, whereas the old standard was limited to 528 MB. Because of its lower cost, enhanced EIDE has replaced SCSI in many areas.
EISA: Extended Industry Standard Architecture
Extended Industry Standard Architecture (EISA) is a bus architecture designed for PCs using an Intel 80386, 80486, or Pentium microprocessor. EISA extends the ISA bus architecture to 32 bits and allows more than one CPU to share the bus. The bus mastering support is also enhanced to provide access to 4 GB of memory. Unlike MCA, EISA can accept older XT and ISA boards — the lines and slots for EISA are a superset of ISA.
ELD: Electroluminescent Display
Electroluminescent display (ELD) is a technology to produce a type of a flat-panel display, used in some portable computers. An ELD works by sandwiching a thin film of phosphorescent substance between two plates. One plate is coated with vertical wires and the other with horizontal wires, forming a grid. When an electrical current is passed through a horizontal and vertical wire, the phosphorescent film at the intersection glows, creating a point of light, or pixel.
ELF emission
Extremely Low Frequency (ELF) emission is radiation emitted by a computer monitor and other common electrical appliances. ELF emissions fall into the range of 5 to 2000 hertz and decline with the square of the distance from the source. Emissions are not constant around a monitor; they are higher from the sides and rear and weakest from the front of the screen. Low-emission models are available, and laptop computers with an LCD display do not emit any ELF fields. There is considerable debate about whether ELF emissions from computer monitors pose a threat. Some European countries have adopted regulations controlling the amount of allowable emission. The most well-know regulation is Sweden's MPR II standard. You can play it safe by buying MPR II-compliant monitors.
EM64T: Extended Memory 64-bit Technology
Extended Memory 64-bit Technology (EM64T) is Intel's implementation of AMD64, a 64-bit extension to the IA-32 architecture. Intel's first processor to actively implement the EM64T technology is the processor sold as Xeon. Intel is selling EM64T-enabled Pentium 4s on the market as the Pentium 4, model F.
embedded system
Embedded system is a combination of computer hardware and software, and perhaps additional mechanical or other parts, designed to perform a special function, contrast with general-purpose computer. An embedded system is a programmed hardware device. In some cases, embedded systems are part of a larger system or product, as in the case of an antilock braking system in a car.
Energy Star
A voluntary labeling program of the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy that identifies energy efficient products. Qualified products exceed minimum federal standards for energy consumption by a certain amount, or where no federal standards exist, have certain energy saving features. Such products may display the Energy Star label.
Enhanced Keyboard
Enhanced keyboard, designed by IBM, has 101- or 102-key. The major difference between this and previous XT/AT keyboards is the twelve function keys arranged in a line across the top of the keyboard as opposed to ten grouped on the left hand side of the keyboard. Nearly all PCs made today come with an Enhanced Keyboard.
EPLD: Electrically Programmable Logic Device
Electrically Programmable Logic Device (EPLD) is an integrated circuit that is comprised of an array of programmable logic devices that do not come pre-connected; the connections are programmed electrically by the user.
EPROM: Erasable Programmable Read-Only Memory
Erasable Programmable Read-Only Memory (EPROM) is a type of computer memory chip that retains its data when its power supply is switched off. It is an array of floating gate transistors individually programmed by an electronic device that supplies higher voltages than those normally used in electronic circuits. Once programmed, a EPROM can be erased only by exposing it to strong ultraviolet light. EPROMs are easily recognisable by the transparent window on the top of the package, through which the silicon chip can be seen, and which admits UV light during erasing. To write to and erase a EPROM, you need a special device called a PROM programmer or PROM burner.
erasable optical disk
Erasable Optical Disk is a type of optical disk that can be erased and re-loaded with new data. In contrast, most optical disks such as CD-ROMs, are read-only.
error correcting memory
see ECC memory.
eSATA: External Serial ATA
External Serial ATA (eSATA) is an enhanced storage interface. The initial SATA was designed as an internal or inside-the-box interface technology. With eSATA, customers can utilize shielded cable lengths up to 2 meters outside the PC to take advantage of the benefits the SATA interface brings to storage. eSATA provides more performance than existing solutions and is hot pluggable. , bringing improved performance and new features to internal PC or consumer storage.
expanded memory
Expanded memory, also known as Expanded Memory Specification(EMS), is a technique for utilizing more than 1MB of main memory in DOS -based computers. The limit of 1MB is built into the DOS operating system. The upper 384K is reserved for special purposes, leaving just 640K of conventional memory for programs.
expansion board
Expansion board is a printed circuit board that you can insert into a computer to give it added capabilities to core controller boards. It is available to provide a number of different features and capabilities such as data acquisition, a complete user-interface solution, or mass-media storage.
expansion bus
The expansion bus, also known as external bus, is made up of the electronic pathways that connect the different external devices, such as monitor, printer etc, to the computer. These external devices connect to ports on the back of the computer. Those ports are actually part of a small circuit board or 'card' that fits into a connector on your motherboard inside the case. The connector is called an expansion slot. Traditionally, PCs have utilized an expansion bus called the ISA bus. All new PCs have a PCI bus for performance as well as an ISA bus for backward compatibility.
expansion slot
Expansion slot is the slot located inside a computer on the motherboard or riser board that allows additional boards to be connected to it. The main types of IBM compatible expansion slots found are ISA, EISA, VESA, PCI, AGP, AMR, and CNR. Expansion slot allows a circuit board to be inserted to add new capabilities to the computer. Nearly all personal computers except portables contain expansion slots for adding more memory, graphics capabilities, and support for special devices. The boards inserted into the expansion slots are called expansion boards, expansion cards, cards, add-ins, and add-ons.
extended memory
Extended memory refers to memory above the first megabyte of address space in an IBM PC with an 80286 or later processor. Two types of memory can be added to a PC to increase memory beyond 1MB: expanded memory and extended memory. Extended memory is not directly available in real mode, only through EMS, UMB, XMS, or HMA; only applications executing in protected mode can use extended memory directly. In this case, the extended memory is provided by a supervising protected-mode operating system such as Microsoft Windows.
external bus
The external bus, also known as expasion bus, is made up of the electronic pathways that connect the different external devices, such as monitor, printer etc, to the computer. These external devices connect to ports on the back of the computer. Those ports are actually part of a small circuit board or 'card' that fits into a connector on your motherboard inside the case. The connector is called an expansion slot. Traditionally, PCs have utilized an expansion bus called the ISA bus. All new PCs have a PCI bus for performance as well as an ISA bus for backward compatibility.
external data bus
External data bus connects a computer to peripheral devices externally, for example, the Universal Serial Bus (USB) and IEEE 1394.
external hard drive
An external hard drive is a hard disk placed outside of the computer case. This allows expandability even if a computer's drive bays are full, and also provides an easily removable form of mass storage with very large capacity. A variety of connections are used to connect external hard drives. SCSI and SATA connections are used when the corresponding type of hard drive is inside, with the case containing a simple pass through. USB and Firewire connections require circuitry to convert the hard disk's connection, which is usually IDE, to USB, firewire, or both.
external modem
External modem resides in a self-contained box outside the computer system, while an internal modem, which resides on a printed circuit board inserted into the computer. Exernal modem uses COM port to connect to the computer.