4. Hercules Operations

4.1 Starting the Emulator

When the Hercules Emulator is started it expects a configuration file to build the hardware configuration.
The name of this file can be provided in different ways.

If Hercules is started with option “-f configfile”, where configfile specifies the name (and optionally
the path) of the desired configuration, then this file is used to build the configuration. If there is an environment variable called “HERCULES_CNF” defined, which contains the name
(and optionally the path) of a configuration file, then this file is used to build the configuration. Finally Hercules looks for a file with the default name “HERCULES.CNF” in the current directory
where Hercules was run from.

If a valid configuration file could be found then Hercules builds the hardware configuration based on this
file. If however no valid configuration file could be found then message HHC01432S is issued and Her-
cules is immediately terminated.

4.2 The Console Panel

After starting the emulator you are presented with the Hercules console panel. This panel displays the log
and some status information and is used to enter Hercules console commands.

Figure 1: Hercules Console Panel

The console panel can be divided into four different areas:

Window title Log area

Command line Status line

Each of these areas is described in more detail in the following sections.

4.2.1 Window Title

The default window title is a string consisting of the following information:

“LPARNAME – SYSTYPE * SYSNAME * SYSPLEX – System Status: colour”

LPARNAME is the value taken from the correspondent system parameter or console command. SYS-
TYPE, SYSNAME and SYSPLEX are populated by the system call SCLP Control Program Identification.
If any of these values is blank, then that field is not presented in the window title. The system status can
either be green, amber or red and has the following meanings:

GREEN Everything is working correctly. AMBER One or more CPUs are not running. RED One or more CPUs are in wait state.

Figure 2: Console Panel - Window Title

The title of the Hercules window can be customized through the PANTITLE system parameter or console
command. To create the window title shown in the figure above the following PANTITLE system para-
meter was used:

PANTITLE "Hercules Emulator HMC - MVS V3.8J"

The window title can also dynamically be changed through the PANTITLE console command which looks
the same as the system parameter shown above.

4.2.2 Log Area

The log area displays Hercules’ log output. This output can also be written to a log file, if requested. In the
log area all Hercules messages are displayed, as well as every command entered and the response re-
turned from Hercules.

This area may also show the system console output of the operating system running under Hercules, if
there is no system console defined in the configuration file and the operating system console output is
routed to the Hercules console instead.