Feersum miSim DE 2.0 Manual

Chapter 3 - User Guide Continued

Updating MiSim DE

miSim DE supports Web Update which allows new components to be downloaded and installed automatically, as well as upgrading the core software. To be able to use Web Update, you will need your computer connected to the Internet. Web Update uses HTTP transfers to exchange information with the Feersum Technology Server, so it should be possible to upgrade the software from behind a firewall. A proxy server may also be specified (see the preferences section earlier in this Chapter).

Updates may include new Plugins to use, source code packages, documentation, tools and newer versions of the files that were installed with miSim DE. To check for available updates, simply click the 'Update' menu item in the File menu. miSim DE will contact the server for a list of currently available updates. If there are any announcements, they will be displayed in a simple dialog before the main update dialog is displayed:

The Update dialog displays a list of new updates that have not yet been downloaded and installed. Selecting an update will display more information on what it provides immediately below the list box. By clicking the 'Select Multiple' checkbox, it is possible to select more than one Update, so that a number of Updates can be installed in one go.

Once the required Updates are selected, clicking the 'Update' button will start to download them. Each Update is downloaded, decompressed and installed in turn. Once all of the updates have been installed, a summary of the changes made will be displayed. Where possible, miSim DE will make the updates immediately available. However, if the update replaces a file that is in use (for instance upgrading a Plugin, or the core software) then it will be necessary to re-start miSim DE. If a restart is necessary, a dialog will be displayed explaining that the user should quit and restart the software.

Pressing Cancel will stop the current download and install no more files. Note that it can take a short time before the update stops.

All actions taken during the Update process are displayed in the main Log window, so that it is possible to see exactly which files have been installed.

Update Security

To ensure that updates are safe, miSim DE takes a number of precautions. However, installing any new software on your computer will always carry a small element of risk. To minimise this risk, Feersum Technology will check updates with recent virus-scanning software before making them available. The update is then compressed and encrypted with a secure key. This protects the update from being tampered with in any way - and ensures that Updates can only be provided by servers trusted by Feersum Technology.

When an update is installed, the Log window displays the names of all files that are stored on the user's machine. Updates may not contain files that are stored anywhere other than within the miSim install directory.

Update cannot replace any files that are currently in use. If a java archive (.jar) file is on the system CLASSPATH, it cannot be replaced by the Update facility. miSim DE uses its own classloader to identify recently updated java files and install them as necessary when it starts up. To ensure that Web Update works correctly, miSim DE should always be started through the 'misim.bat' or 'start_misim' script files. The system CLASSPATH should not be changed to run miSim DE.