User Guide

Ampex 1308911-02 A-11
Glossary and Acronyms Glossary
Tape Drive Buffer A temporary storage area that the DST drive uses to hold data being
transferred to or from the tape. In write mode, the drive uses the buffer
to store data that the DST Driver has written to the drive, but which the
drive has not yet transferred to the tape itself. In read mode, the drive
uses the buffer to read in data from the tape in anticipation of future
read requests by the DST Driver.
Terabyte (TB) 2
40
(1024*1024*1024*1024 or 1,099,511,627,776) bytes.
Token Position A form of storing the current position in a packed byte array. The token
position is portable across all host architectures and I/O protocols
because it is not subject to byte-swapping.
Trace Log A log maintained by the DST tape drive that records drive events. This
log can be retrieved for diagnostic purposes.
Transport Control Function (TCF)
The part of the DST tape drive that controls tape motion hardware,
servos, read/write electronics, and related support equipment.
Communicates with the PCF. On the DST310, the TCF is
implemented on the AST/CTRL board. Also sometimes called
Transport Module.
UID User ID. A number that uniquely identifies a user on a host system.
Often paired with the user’s uname. See user, uname.
Uname User name. A name that uniquely identifies a user on a host system.
Often paired with the user’s UID. See UID, user.
Unbuffered Mode An I/O mode in which every application write request results in an
immediate physical I/O operation. In this mode the tape drive data
buffer is synchronized for every request.
Unload Disables the DST drive from accepting any more medium access
commands. Sometimes synonymous with Eject. See Eject.
User A person or process using a service. A given user can have certain
privileges for accessing a particular resource. For example, the root
user can perform operations that are forbidden to other users.
User Interface The means by which a user interacts with a system. In the DST Device
Driver context, refers to the mechanism by which client applications
interact with the DST Device Driver. This user interface can be
conditioned by the user’s access rights and the nature of the device
special file in use.
Volume A tape partition. A DD-2 tape may consist of one or more volumes.