Each of these views is explained in more detail in the following sections.

4.4.1 System Log

When accessing the web browser interface the system log is the first view displayed. It shows an excerpt
of the current Hercules log.

Per default the last 22 lines of the Hercules log are displayed. There is an entry field in the last line of the
log display to change number of lines. The number entered here specifies the number of log lines that are
displayed in a scrollable window. Specifying zero allows browsing through all log lines.

Figure 15: Web Browser Interface – System Log

Through clicking on the “Auto Refresh” button, the view is refreshed automatically. The refresh interval in
seconds can be specified in the entry field beneath the “Auto Refresh” button. Once auto refresh is turned
on you can stop it by clicking again on the same button, whose description meanwhile has changed to
“Stop Refreshing”.

The command entry field can be used to enter any Hercules command. Click on the “Send” button to sub-
mit the command in the entry field.

4.4.2 IPL

The IPL view is used to perform an Initial Program Load (IPL). You can select the CPU, the device to IPL
from and an optional IPL parameter. The IPL parameter is used for the IPL of the intended operating sys-
tem. The parameter is operating system dependent, consult the relevant operating system documentation
for details. Clicking on the “IPL” button performs the Initial Program Load with the chosen values.

Figure 16: Web Browser Interface – IPL

4.4.3 Registers

When displaying the registers view, the general purpose registers, the control registers and the access
registers are hided initially. To view the registers click on the according “Select xxxx Registers” button.

When the registers are displayed the button changes to “Hide xxxx Registers”. Click again on this button
to hide the selected registers view. Depending on the current architecture mode some of the register sec-
tions may not be available.

Figure 17: Web Browser Interface – Register Selection

On top there is a drop-down box to select the CPU for which the registers should be displayed. Click on
the “Select” button after choosing the CPU from the drop-down list.