system menu icon. The term for the symbol found in
the top left-hand corner of some windows that is used to
control the presence and appearance of those windows.
See

system menu

.
T
TCP. Transmissioncontrol protocol. A form of LAN
communications protocol.
TCP. TelecommunicationsCarrier Products. A form of
LAN communications protocol.
tape drive. Adevice that is used for moving magnetic
tape and includes the mechanisms for writing and
reading data to and from tape. See also

tape unit

and

transport

.
tape library. Aterm used to refer to the customer’s
collection of tapes. Within the IBM 3494 TapeLibrary,
this simply means the set of cartridges contained within
the enclosure.
tape library dataserver. Anautomated tape library
consisting of mechanical components, cartridge storage
frames, IBM tape subsystems, and controlling hardware
and software. The tape library dataserver performs tape
cartridge mounts and demounts without operator
intervention.
tape management software. Aprogram that controls
the scratch status of tape volumes.
tape unit. Adevice that contains tape drives and their
associated power supplies and electronics.
tape volume cache. The Tape Volume Cache is a
major component of a Virtual TapeServer and is a
combination of RAID DASD, RAM buffering and internal
licensed code that stores and manages virtual volumes.
teach. The process that allows the library manager,
using the cartridge accessor,to

learn

the exact physical
locations of each major unit within the tape library.
telecommunications carrier products (TCP). A form
of LAN communications protocol.
title bar. The area at the top of each window that
contains the window title and system-menu icon. When
appropriate, it also contains the minimize, maximize,
and restore icons.
token-ring network. A local area network (LAN) that
uses ring topology,where tokens are passed from node
to node.A node that is ready to send can capture a
token and insert data for transmission.
transient cartridges. Cartridges that reside in a
customer’s library that are not stored within the confines
of the automated tape library and are not recorded as
part of the automated library’s inventory.
transient mount. See

mount from input station

.
transmission control protocol (TCP). A form of LAN
communications protocol.
transport. The mechanism inside a tape drive that
moves tape media. It is comprised of loading, threading
and guiding mechanisms and motors.
U
unavailable. Aterm used to indicate that a component
in the tape library (for example, the cartridge accessor)
is unavailable for use by the library manager.Compare
with

Offline

. Contrast with

available

.
unit. (1)An entity capable of accomplishing a specific
purpose; for example, a 3490E tape drive. (2)An
individual piece of the tape library that can be added or
deleted from a tape library configuration, for example,
3490E control unit, 3490E tape unit, storage frame, or
Convenience Input⁄Output Station.
unit emergency power off (UEPO). The 3494 switch
that, when operated in an emergency,cause the 3494
to be disconnected from the ac power source.
unit power off (UPO). A switch that removes all power
from a specific units of the tape library.
unload. Toremove cartridges from a 3490E drive.
V
VTAM. VirtualTelecommunications Access Method. A
form of LAN communication protocol.
VTS. AVirtual Tape Server is comprised of a Virtual
TapeServer controller, 3590 tape devices and the 3494
TapeLibrary. Together they manage the utilization of the
cartridge storage capacity and performance capabilities
of the 3590 tape technology transparently to host
software and applications.
virtual tape drive. A virtual tape drive is a
representation of the functionality of a 3490E class tape
drive as viewed by the host control program. The data
from/to the drive is directed to the TapeVolume Cache
and all drive related commands are emulated through
the internal licensed code in the Virtual TapeServer
controller.
virtual tape server (VTS). A Virtual Tape Server is
comprised of a Virtual TapeServer controller, 3590 tape
devices and the 3494 TapeLibrary. Together they
manage the utilization of the cartridge storage capacity
and performance capabilities of the 3590 tape
technology transparently to host software and
applications.
virtual volume. Avirtual volume is a customer
accessible volume that exists in the TapeVolume Cache
Glossary 345