IBM OS/390 manual O s s a r y

T

task. (1) In a multiprogramming or multiprocessing environment, one or more sequences of instructions treated by a control program as an element of work to be accomplished by a computer. (2) In VSE, the basic unit of synchronous program execution. A task competes with other tasks for computer system resources such as processing time and I/O channels.

Telnet. In TCP/IP, an application protocol that allows a user at one site to access a remote system as if the user′ s display station were locally attached. Telnet uses the Transmission Control Protocol as the underlying protocol.

temporary data set. A data set that is created and deleted in the same job. Contrast with nontemporary data set.

temporary storage. In computer programming, storage locations reserved for intermediate results. Synonymous with working storage.

test plan. A plan that establishes detailed requirements, criteria, general methodology, responsibilities, and general planning for test and evaluation of a system.

Time Sharing Option (TSO). An operating system option; for the System/370 system, the option provides interactive time sharing from remote terminals.

token-ring network. A network that uses a ring topology, in which tokens are passed in a circuit from node to node. A node that is ready to send can capture the token and insert data for transmission.

transaction processing. A sequence of operations on a database that is viewed by the user as a single, individual operation.

transient. Pertaining to a program or subroutine that does not reside in main storage or to a temporary storage area for such a program.

transparent. (1) Pertaining to operations or data that are of no significance to the user. (2) In data transmission, pertaining to information not recognized by the receiving program or device as transmission control characters.

transportability. Synonym for portability.

TSCF. Target System Control Facility. Part of System Automation OS/390 which uses NetView to allow a host OS/390 system to automate operations at target systems.

TSO/E. time sharing option/extended. An option on the operating system; for System/370, the option provides interactive time sharing from remote terminals.

U

unit address. The three-character address of a device, specified at the time a system is installed; for example, 191 or 293.

unit of work. In advanced program-to-program communications, the amount of processing that is started directly or indirectly by a program on the source system.

update authority. The ability to add, change, or cancel items.

upward compatibility. The capability of a computer to execute programs written for another computer without major alteration, but not vice versa.

user catalog. See VSAM user catalog.

user exit. A programming service provided by an IBM software product that may be requested during the execution of an application program for the service of transferring control back to the application program upon the later occurrence of a user-specified event.

user identification (user ID). (1) A string of characters that uniquely identifies a user to a system.

(2)The name used to associate the user profile with a user when a user signs on the system.

user interface. (1) Hardware, software, or both that allows a user to interact with and perform operations on a system, program, or device. (2) In SAA usage, any of the actions or items defined by Common User Access (CUA) architecture that allow a user to interact with and perform operations on a computer.

user profile. In computer security, a description of a user that includes such information as user ID, user name, password, access authority, and other attributes obtained at logon.

user program. A user-written program.

user-defined word. In COBOL, a word that must be supplied by the user to satisfy the format of a clause or statement.

utility program. A computer program in general support of computer processes; for example, a diagnostic program, a trace program, a sort program. Synonymous with service program.

G l o s s a r y 581