User Guide

ManualsBrandsAmpex Data Systems ManualsOtherDSTDIS TAPE DRIVE PROGRAMMER S GUIDE, PART NO. 1308911-02

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Ampex 1308911-02 A-3

Glossary and Acronyms Glossary

Current Position An indicator that speciﬁes the tape location at which the next I/O

operation is to occur. See also Position.

Data Block A series of consecutive bytes of a ﬁxed length that comprises the

logical unit in which an application transfers data to or from a device.

Any given ﬁle section on tape has only one data block size. Each data

block is followed by a two-byte checksum, unless the checksum

feature has been disabled. See also Physical Block.

Data Block Number (DBN)

Number identifying a logical data block, either within a ﬁle section or

a partition. See Logical Data Block Number and Cumulative Data

Block Number.

Data Block Size The number of bytes in a data block, excluding the checksum.

DD-2 (Data Digital-2) An ANSI format for helical scan digital storage magnetic tape.

Default Data Block Size

The data block size conﬁgured for a speciﬁc device special ﬁle. The

default data block size is in effect when the device is opened and

remains in effect until changed by program action.

Default Data Partition

The ﬁrst partition on a tape. The mtio-compatible interface sets the

partition context to the default data partition when the interface is

opened.

Density The amount of data that can be stored on a pre-deﬁned length of tape.

This is a ﬁxed non-conﬁgurable value for all DD-2 tapes, as described

in the ANSI DD-2 standard.

Device Driver An operating system module that provides a programmatic interface a

device. The DST Driver is a device driver installed as part of the Unix

kernel and provides access to a DST tape drive.

DD-2 interface A device interface tailored to the DD-2 tape format. This interfaces

allows full use of the DST tape drive capabilities. Sometimes called

Full-function interface.

Device Special File An operating system pseudo ﬁle that forms the interface to a device. A

single physical device can have multiple device special ﬁles, each with

speciﬁc attributes that condition the nature of the interface.

Double Frame (DF) A group of 32 consecutively recorded helical tracks that hold single

physical block of data on a tape.

Drive See Tape Drive.