Before you assemble your program

When you debug an assembler program, you can use most of the z/OS® Debugger commands. There are three differences between debugging an assembler program and debugging programs written in other programming languages supported by z/OS Debugger:

• After you assemble your program, you must create a debug information file, also called the EQALANGX file. z/OS Debugger uses this file to obtain information about your assembler program.
• z/OS Debugger assumes all compile units are written in some high-level language (HLL). You must inform z/OS Debugger that a compile unit is an assembler compile unit and instruct z/OS Debugger to load the assembler compile unit's debug information. Do this by entering the LOADDEBUGDATA (or LDD) command.
• Assembler does not have language elements you can use to write expressions. z/OS Debugger provides assembler-like language elements you can use to write expressions for z/OS Debugger commands that require an expression. See IBM z/OS Debugger Reference and Messages for a description of the syntax of the assembler-like language.

After you verify that your assembler program meets these requirements, prepare your assembler program by doing the following tasks:

1. Assembling your program.
2. Creating the EQALANGX file for an assembler program.

Assembling your program and creating EQALANGX describes how to prepare an assembler program by using IBM® z/OS Debugger Utilities.