Appendix Ai Job Control Language; Simple Jcl Execution; Simple Jcl Compiling - Radio Shack TRS-80 Model 4 Owner's Manual

Appendix AI Job Control Language
The TRSDOS Job Control Language (JCL) is one of the most
powerful features of TRSDOS. It consists of:
• TRSDOS commands
• Macros
• Special symbols
You can use JCL to make your computer more "user friendly." That
is, you can write JCL programs that perform a variety of functions,
such as FORMAT and BACKUP, and have TRSDOS execute these
functions when the user types in one command line.
If you have read the entries on the BUILD and DO commands, you
know how to create a JCL file composed of TRSDOS commands.
You can make this file more powerful by utilizing macros and other
features of JCL. This section describes how.
The steps for creating and using a JCL file are:
1. Create a JCL file consisting of TRSDOS commands, macros, or
special symbols. You can do this with the BUILD command,
SCRIPSIT, or a BASIC program.
2. Execute the JCL file with the DO command. This causes the JCL
processor to:
• Take control of the keyboard (for line input)
• Read a line in the DO file exactly as if it came from the
keyboard
• Return control of the keyboard to the user when it reaches the
last line.
The following sections give complete information on all the JCL
features:
• Simple JCL Execution
• Simple JCL Compiling
• Advanced JCL Compiling
A-3