Dallas Computer Repair | Computer Repair Terms "D"

Data- Raw facts and figures assembled as information in small units.

Data Bus- The microprocessor is connected to the memory and I/O devices through a bidirectional pathway and its size usually corresponds to the word size of the computer.

Data Communication Equipment (DCE)- Usually a modem, it is a communication device that establishes, maintains and terminates data-transfer sessions and serves as a data converter when connecting different media.

Data Compression- Complex algorithms remove redundant bits like successive 0s or 1s from data streams and the decompression circuitry reinserts the missing bits to return the data to its original state.

Data Encryption Standard- A U.S. government encryption standard method that turns data into unbreakable, secret code.

Data Set Ready (DSR)- The message sent from the modem to its own computer telling it is ready to accept data and is an RS-232 handshaking signal.

Data Terminal Ready- The message sent to a modem by its own computer telling it is ready to accept data and is an RS-232 handshaking signal.

Default- A normal setting or action of the hardware or software without the user's other specification.

Defragmentation- A disk operation maintenance that moves scattered file fragnemts into optimized, continuous chains of data to speed up retrieval from the drive.

Demodulator- A device that takes data from a carrier frequency and converts it back into its original, unmodulated form.

DEVICE= Commands from CONFIG.SYS that load device drivers into memory at bootup. DEVICEHIGH= moves the drivers into the upper memory block freeing up conventional memory space.

Device Driver- A program that resides in the memory and allows the operating system to communicate with a particular type of device like a keyboard or mouse.

Device Manager- A Windows Control Panel utility that gives users a graphical interface indicating devices in the system. The graphic interface can be used to identify and resolve conflicts between system devices, view resource allocations and set hardware configurations properties for the devices. It can be accessed under the System icon and the tab named "Hardware" on Windows XP. An often used utility in the computer repair field.

Diagnostics- Software and hardware that can indicate problems within the system or with the computer hardware. Errors can be reported by beep codes or visual reports. There are software diagnostic programs written on floppies, CDs and DVDs. There also specific hardware that plugs directly into the mainboard and gives digital codes that are cross-referenced to manuals written for that diagnostic hardware to indicate specific problems. A must have in the computer repair field.

Dial-up Networking- Methods where computers access data networks through public telephone systems and includes modems, ISDN and DSL.

DIMMs- Dual in-line memory modules with 168-pin plug-in units that are similar to SIMMs. Replaced rather than repaired in the computer repair field.

Direct I/O- An addressing method of I/O that uses extra control lines without address allocations.

Direct Memory Access (DMA)- The capability of I/O devices to perform intelligent, high-speed data transfers themself with particular IC devices known as DMA controllers.

Directory- (1) A hiearchy of files organized under a heading and organized like a file cabinet. (2) An organizational table on a disk that holds information of all files under the location such as filename, size, time and date of last changes and its beginning location on the disk.