Maxtor manual Maxtor Atlas 10K V G-3

GLOSSARY

DATA SEPARATOR – The circuit that extracts data from timing information on drives that store a combined data and clock signal.

DEDICATED SERVO – A positioning mechanism using a dedicated surface of the disk that contains timing and positioning information only, as compared to surfaces that are also used for data. (See also embedded servo.)

DEFECT MANAGEMENT – A technique ensuring long-term data integrity. Consists of scanning disk drives both at the factory and during regular use, de-allocating defective sectors before purchase and compensating for new defective sectors afterward.

DIFFERENTIAL TERMINATION – One of two methods for terminating the SCSI bus, characterized by a two-line signal: a (+) signal and a (-) signal. Used to improve noise resistance when long bus cables are required. See also single-ended termination.

DISK – In general, any circular-shaped data- storage medium that stores data on the flat surface of the platter. The most common type of disk is the magnetic disk, which stores data as magnetic patterns in a metal or metal-oxide coating. Magnetic disks come in two forms: floppy and hard. Optical recording is a newer disk technology that gives higher capacity storage but at slower access times.

DISK CONTROLLER – A plug-in board, or embedded circuitry on the drive, that passes information to and from the disk. The Maxtor hard disk drives all have controllers embedded on the drive printed-circuit board. (See also controller.)

DMA – Direct Memory Access. A process for transferring data directly to and from main memory, without passing through the CPU. DMA improves the speed and efficiency by allowing the system to continue processing even while new data is being retrieved.

DOS – Disk Operating System. The most common operating system used in IBM PCs. Manages all access to data on the disk.

DRIVE – Short form of disk drive.

DRIVE GEOMETRY – The functional dimensions of a drive, including the number of heads, cylinders, and sectors per track. (See also logical format.)

E

ECC – Error Correction Code. The incorporation of extra parity bits in transmitted data in order to detect errors that can be corrected by the controller.

EDC – Abbreviation for error detection code. An end-to-end cyclic redundancy code that is used to protect data from errors that may be introduced by the connecting busses, the disk controller chip, the data cache, or the SCSI interface in a disk drive. See also, CRC.

ELECTRONICS MODULE – The printed circuit board containing the drive electronics.

EMBEDDED SERVO – A timing or location signal placed on tracks that store data. These signals allow the actuator to fine-tune the position of the read/write heads.

ENCODING – The conversion of data into a pattern of On/Off or 1/0 signals prior to being written on the disk surface. (See also RLL and MFM.)

EPROM – Erasable Programmable Read-Only Memory. An integrated circuit memory chip that can store programs and data in a non- volatile state. These devices can be erased by ultraviolet light and reprogrammed with new data.

EXTENDED CONTINGENT ALLEGIANCE – A condition generated by a target and announced with a INITIATE RECOVERY message. The mode is used when multi-step extended error recovery procedures are required to prevent interference as from other initiators in a multi-initiator system. See also contingent allegiance.

EXTERNAL DRIVE – A drive mounted in an enclosure separate from the computer system enclosure, with its own power supply and fan, and connected to the system by a cable.

Maxtor Atlas 10K V G-3