Using the Debugger

When you run a program under the Tachyon Instruction Emulator, you can interact with the program through the debugger. The debugger allows you to display and alter storage and register contents. disassemble your code and set break points and watch points. At any time you can view the history of recently executed instructions.

You may use symbol names in address expressions. The debugger will also attempt to translate most addresses that it prints into offsets within known control sections. If the debugger cannot translate an address, it will display the offset as three question marks (???).

Your interface to this release of the Tachyon Instruction Emulator’s debugger is through the command-line. You can enter commands at the debugger’s prompt. The debugger prompt is normally displayed as tieX> where X is the architecture level. If the program is waiting on one or more ECBs, the prompt is displayed as wait>. Once the program has terminated, the prompt is displayed as stop>.

If the step was marked for debugging via the j390 -debug command line parameter, then the debugger prompt is displayed just before the first instruction of your program is executed. This will be at the program’s entry point. Even if you did not specify that the step was to be debugged, you can enter the debugger by hitting control-C, unless the step was specified with the -nodebug option. You can also interrupt the run command by hitting control-C. You will usually need to hit control-C to get the prompt in order to enter operator console commands through the debugger’s console command. Just before the debugger prompt is displayed for the first time in the job step, the COMMNDxx.ini command files will be processed.

If you do not enter a command at the debugger prompt but instead just hit the Enter key, the Tachyon Instruction Emulator will reexecute the commands from the last line entered. This is especially useful when using the step command. You can also assign frequently used commands to keyboard function keys.

More than one debugger command can be entered on one line. Each command must be separated by a semicolon (;), Since a semicolon at the start of a command indicates the start of a comment, two consecutive semicolons can be used to add a comment to a debugger command line. For example:

To see more debugger lines, you can increase the size of your command line window. For Windows NT, Windows 2000 and Windows XP, you can change the window properties to set the size to be thousands of lines and then use the scroll bar to see any lines that have scrolled out of the viewable area. For Windows 95 and Windows 98 you can enter the following DOS command to increase the window size to 43 lines:

At any time you can issue the help or ? command to see a list of the debugger commands or to get help on an individual command. There are groups of debugger commands for the following tasks:

Frames No Frames Previous Next Contents
Introduction Setup Programs Files Running Testing Compatibility Customization Messages Codes

© Copyright 1998-2002, Tachyon Software® LLC.
Last modified on May 12, 2002