E-F

ECC (Error Correction Code or Error Checking and Correction)

A technique used to test data for errors as it passes out of memory. If errors are found, ECC attempts to make the necessary corrections.

ECP (Extended Capabilities Port)

An IEEE 1284 bidirectional parallel port standard that offers faster transfer rates than traditional parallel port standards. ECP is most often used for communication between computer systems and printers or scanners.

EDO (Extended Data Output)

A type of DRAM that has the ability to read more information before needing to be refreshed. EDO is much faster than its predecessor, FPM DRAM.

EEPROM (Electrical Erasable Programmable Read-Only Memory)

A type of PROM chip whose

can be changed or erased with an electronic charge. EEPROM chips were very popular before the introduction of flash ROM chips.

EFS (Encrypting File System)

A feature first fully implemented with Windows 2000 that enables any file or folder to be stored in an encrypted format by making the encryption an attribute of that file or folder. Only an individual user or an authorized recovery agent can decrypt the file or folder. This feature is extremely useful for storing highly sensitive data.

EGA (Enhanced Graphics Adapter)

IBM introduced EGA in 1984. The EGA standard for video adapters offers a resolution of up to 640 350 and supports up to 16 colors. EGA has been replaced by VGA and is for the most part obsolete.

EIDE (Enhanced IDE)

An enhancement to the IDE hard drive standard that offers access to hard drives larger than 528MB through the use of LBA support. The EIDE standard also offers support for DMA, for up to four attached devices (including tape drives and CD devices), and for faster hard drive access time.

El Torito specification

A standard for CD-ROM drives that allows the computer to boot from a CD-ROM.

EMI (Electromagnetic Interference)

An electronic phenomenon that occurs when the signal from two or more electronic devices interferes with each other. EMI can occur when one data cable is placed too close to a second cable. If the electrical signals cross, the integrity of the information passing along the data cable may be affected.

EMS (Expanded Memory Specification)

A memory management tool used to gain access to memory above the 640K-memory limitation in an MS-DOS-based environment. Advances in the ways that Windows manages access to memory has for the most part eliminated the need for EMS.

environment variable

In Windows and DOS, the setting of the path that enables the system to locate certain Windows program files and commands when entered into the command prompt or Run dialog. Although the term environment variable technically means anything that can be changed in a computer, the aforementioned definition represents the most important and common use of the term. See path.

EPP (Enhanced Parallel Port)

An IEEE parallel port interface standard. Also known as IEEE 1284, EPP supports bidirectional or half-duplex data transmission methods.

EPROM (Erasable Programmable Read-Only Memory)

A ROM chip whose contents can be erased by shining an ultraviolet light through a hole in the top of the chip.

ESD (Electrostatic Discharge)

The movement or transfer of electrons from one location to another. Static electricity can be transferred from the human body to an electronic component, causing damage to the components. ESD can be avoided by wearing an ESD-protective wrist strap when working with components.

Ethernet

The most common network system, usually making use of unshielded twisted-pair cables with RJ-45 connectors.

expansion slots

Slot connectors on the motherboard for attaching various components. Motherboards typically have several expansion slots.

extension, filename

Character(s) after the final period in a filename. The extension tells the OS what type of file it is, and Windows associates certain programs with each known file extension so that the file can be opened with minimum delay. For example, in the file chapter1.txt, “txt” is the extension, and it indicates a text file that would normally be opened by a text editor such as Notepad. Most file extensions are hidden by default in Windows; change this setting by going to Control Panel > Folder Options > View tab and clearing the “Hide file extensions for known file types” check box.

FAT (File Allocation Table)

A table consisting of clusters that are logical units of information located on a hard drive and used by the operating system to identify the location of stored entries or files.

FIFO (First-In, First-Out)

A data storage method in which the oldest information is read or used first.

file system

System of storing data on a disk. File systems discussed in this book are FAT16, FAT32, NTFS, and various optical drive file systems. Not all versions of Windows can access all file systems.

firewall

A hardware- or software-based mechanism for blocking unwanted access to a computer over a network or the Internet.

FireWire

A high-throughput hardware interface standard that allows many devices to be connected to a single port with only the FireWire controller using any Device Manager resources. Synonym: IEEE 1394.

firmware

Flash memory that is used to manage the basic operation of hardware devices. The most well-known example of firmware is a computer’s BIOS. Other devices, such as optical drives, have firmware. Firmware can be updated via a process called flashing.

flash memory

Expensive memory that holds its data indefinitely after the power has been disconnected, but the data can be changed in a process called flashing. Flash memory chips are used for devices such as digital cameras, data storage devices on computers, and BIOSs.

flat panel monitor

A physically thin monitor, such as a laptop monitor, that uses light-emitting semiconductors rather than a glass picture tube. Contrast with CRT monitor.

flat screen monitor

A CRT monitor in which the viewable portion of the glass picture tube is flat, not curved. Not to be confused with a flat panel monitor.

floppy disk drives

Devices that store data on removable magnetic disks. Virtually all floppy drives sold since the mid-1990s have been of the 3.5-inch variety. These floppy disks are enclosed in a thin, hard, plastic shell. Because of this, they are sometimes confused with hard drives. Because of their limited capacity, their susceptibility to data loss, and other reasons, floppy disks have become much less useful in recent years. However, floppy disks can be indispensable for certain repairs. Synonyms: floppies, diskette drives, FDDs.

folder

A virtual container used by Windows to organize files. Formerly called directories.

form factor

A standard of shapes, sizes, and mounting designs of hardware devices such as cases, power supplies, motherboards, hard drives, and others.

FPM (Fast Page Mode)

A DRAM memory type that makes use of memory paging, which increases overall memory performance. Most DRAM memory types are FPM.

FPU (Floating-Point Unit)

A math coprocessor that is built into the CPU. An FPU is designed to handle higher-end mathematical equations that assist with today’s complex formulas and graphical calculations.

Front Side Bus (FSB)

The channel that connects the processor with main memory. The faster the FSB, the better the performance. As of this writing, this number will range between 33 and 800 MHz.

FRU (Field-Replaceable Unit)

An interchangeable or replaceable computer part or component that can be installed at a customer’s site or remote business location by a computer technician.

FTP (File Transport Protocol)

A transfer protocol primarily used on the Internet to transfer files from one location to another.