Display a symbolic procedure stac k trace, optionally displa ying interleaved Native Mode (NM) and Compatibility Mode (CM) calls. Y ou can also temporarily set the curren t debug environment back to the environment that existed at an y marker in the stack.

Calculate the value of expressions to determine the correct v alues of variables at a giv en point in a program. Values can be custom formatted in sev eral bases.

Use full screen displa ys (windows) that allow you to inspect registers, program code, the current stack frame, and the top of stac k. Groups of custom user windo ws can be aimed at important data bloc ks to dynamically monitor c hanging values.

Display on-line help for all commands, prede￿ned functions, and en vironment variables.

Create and reference user-de￿ned v ariables.

De￿ne powerful, parameterized macros. Y ou can invoke macros as new commands to perform sequences of commands or as functions within expressions that return single v alues.

De￿ne aliases for command and macro names.

Execute commands from a ￿le, record all user input to a log￿le, and record all DEBUG output to a list￿le.

MPE/iX User Interface

MPE/iX has a user in terface that includes a command language, on-line HELP facility , user-de￿ned commands (UDCs), and command ￿les.

The MPE/iX command language is processed b y the Command Interpreter. It con tains all necessary commands to direct and con trol the system.

You can enter identical MPE/iX commands during a session or through a job; MPE/iX has no separate control language for jobs. Y ou can also issue MPE/iX commands in a command ￿le.

Actions MPE/iX commands can perform include: Initiate and terminate jobs and sessions.

Run system programs and utilities.

Compile, link, load, run, and debug programs.

Create, maintain, and delete ￿les.

Display ￿le information.

Display job, session, or device status.

Transmit messages.

Establish comm unication with local and remote computers.

Control and manage system resources.

If the command in terpreter (CI) detects an error in command syn tax in interactive mode (during a session), it pro vides a descriptiv e error message specifying the erroneous parameter and prompts you to correctly reen ter the command. If it detects a syn tax error while running, it lists the error on the output device and halts the job.

1-12 OVERVIEW