Introduction - IBM System 360 User Manual

Introduction
TSO is the time sharing option of the IBM System/360 Operating system.
TSO le~ you use the facilities of a computer at a terminal. A terminal
is a typewriter-like device connected through telephone or other
communication lines to the computer. A terminal can be at any distance
from the computer -- in the same room or in another city. Because the
system processes instructions much faster than you can enter them
through the terminal, it can process input from many terminals at the
same time it is processing work entered in the conventional manner in
the computer room. However
I
due
to
the speed of the system,· you will be
able to work as though you had almost exclusive use of the system.
You can tell the system what work you want done by typing in one or
more of the commands that form the TSO command language.. The command
language can be used to:
• Enter", store, modify, and retrieve data at the terminal.
• Solve mathematical problems.
• Develop programs written in Assembler, FORTRAN, COBOL, PLlI, or
other languages.
• Execute programs.
• Control the operation of a system with TSO from the terminal.
Your installation determines which of the facilities of the system
you can use. That is, the installation determines which commands are
available to you.
When you enter a command in the system, the system performs the work
requested by that command and sends messages back to your terminal. The
messages tell you the status of your program and whether the system is
ready to accept another command. You can interrupt the processing of a
command at any time and enter a new one.
If you make a mistake typing in a command, or if you fail to include
some necessary information with the command, the system sends you a
message prompting you for the necessary information. You may then
respond by typing in the information requested.
If you receive a message you don't understand, you can type in a
question mark to request more information. The system will then send
you a more detailed message, if available.
Whenever you are not sure which command to use or how to use a
particular command, you can type HELP. HELP is a command that provides
you with information on all other TSO commands.
This manual explains how to use the command language. The manual is
divided into the following sections:
1. What you must know to use TSO.
2. Starting and ending a terminal session.
3. Entering and manipul"ating data.
4. Programming at the terminal.
S. Testing a program.
6. Using and writing command procedures.
7. Controlling a system with TSO.
Introduction 9