Virtual Microscope Java Client Help Page

You have been directed to this page, because the Virtual Microscope Java Client (VM Client) is not working correctly.

To get around the security limitations of Java Applets, we have designed the VM Client to use Sun's Java Plugin. This is a piece of software that is used by the VM Client instead of the version of Java that was included with your web browser. Once the Plugin is successfully installed, the Plugin must be configured to relax the security restrictions and increase available memory for the VM Client to run.

1. Install Sun's Java Plugin

As with any plugin, you first use your web browser to display a page that tries to use a plugin. If the plugin is not currently installed on your machine, you will be prompted to install it. The next step is web browser specific. Go here to install the plugin, if needed.

Microsoft Internet Explorer: Current versions of IE will automatically download the plugin from Sun and start the installation process.

Netscape Navigator: Current versions of Navigator (including Communicator) will open new web browser window with Sun's page, but will not download the correct one automatically. You must manually start the download using the web site. Once it is downloaded, you must also find and execute the file you downloaded to start the installation process.

2. Configure the Java Plugin

The Java Plugin now needs to be configured to allow the VM Client to run. This depends on your operating system.

Windows 95/98/NT: The Java Plugin adds a new menu selection at Start -> Programs -> Java Plugin Control Panel.

Solaris: The Java Plugin creates a java/ directory under ~/.netscape to put its files. The Java Plugin Control Panel can be started in two ways. From the command line, execute ~/.netscape/java/ControlPanel. From a web browser you can load ~/.netscape/java/ControlPanel.html.

Two items will need to be changed:

1. The Network access option must be changed from Applet Host to Unrestricted. This allows the VM Client to open a network connection to the VM Server for requesting slide image data.
2. The Java Run Time Parameters option should have the following added: -mx100000000 -ms10000000. Note there are 8 zeros after mx and 7 zeros after ms. This forces Java to allocate more memory for use by applets. The VM Client uses a large amount of memory to store the thumbnail image and to hold high resolution image data returned by the VM Server.

After the changes are made, click on the Apply button. The Java Plugin Control Panel should now appear as shown below.

3. Use the VM Client

At this point, the Java Plugin should allow the VM Client to execute correctly. Reload the original page in your web browser. The status line should indicate the Java Plugin is being started, and then the VM Client should start.

There are still some potential problems which could keep the VM Client from executing:

1. The Java Plugin may need to be restarted for the Control Panel changes above to be seen. Exit, restart your browser, and try again.
2. The web page is incorrectly pointing to a VM Server that is not really running. Notify the person(s) responsible for the VM Server you are trying to connect to and have it started.

Last modified October 14, 1998