Our Computing Environment

In this document, we discuss our computing environment for this course. Our goal is first and foremost, to make sure that you have a consistent and working environment, and secondly, to allow you to use this environment from varying locations both on and off campus.

To this end, each of you has been given an account on our department server, patel2.slu.edu, for use in this class. We strongly recommend that you use this machine for all of your coursework, as it will be our supported environment. All of the software and documentation that we use in the course will be installed on this machine and maintained by our staff, and you will be able to access the machine from any remote location with an Internet connection (though slower connections will be less pleasant).

At the same time, it is possible for students to install the necessary software on their personal computers. We have intentionally chosen to use software for this course which is freely available for public use and reasonably easy to install. Unfortunately, due to the many varieties of hardware, operating systems, and configurations on individuals' computers, we cannot offer official support to this end.


Using patel2.slu.edu

Each of you has been given an account on our department server, patel2.slu.edu, for use in this class. Your username and passwords were set based upon your questionnaire's, with adjustments when necessary. This machine is running a Linux Operating System (specifically gentoo linux).

In order to let you access patel2 from other machines, while using a Graphical User Interface, we will be relying on open source software known as Virtual Network Computing (VNC). To use this via the Internet, please open a web browser and go to the URL patel2.slu.edu/vnc/.

You will then be given a choice of desktop sizes. You may pick any of the sizes, however the larger the size, the more bandwidth you will need to effectively use the connection without unwanted delays. Also, if you pick a desktop that is larger than the size of your physical monitor, you would have to use scrollbars to see all parts of the virtual desktop; this is very inconvenient.

From Shannon Hall, we recommend 1024x768. In other locations you can experiment with the choice of sizes. Once you select a size, you should soon see a new window appear on your computer which looks something like:

Our suggested Window Manager: KDE

We will be using a Window Manager on the Linux system known as KDE. The Window Manager is what controls your graphical user interface.

First time log-in

Before the first time first log in via the above screen, you must select your window manager. Before logging in, click on the "Session" menu near the top right corner, and select "kde-3.1.3" as your choice. Now, enter your username and password; if you have trouble with this authentication, please speak with the instructor to review your credentials.

If your username/password was accepted, you will next see a dialog box asking whether you wish to make "kde-3.1.3" as your default for future sessions. Select "Yes" and then it will remember this preference for the future so that you do not need to explicitly select it each time.

The first time you log in with KDE, it automatically brings up a "Personalizer" to configure KDE for your use. KDE will allow you to choose a familiar look-and-feel similar to that of UNIX, or Microsoft Windows or Apple MacOS.

For the "Eye Candy" setting, I would strongly suggest that you go with the lowest setting due reduce bandwidth for our remote connections. You can always experiment with increasing this at a later time.

If you later wish to modify any of these settings, you can do so by selecting "Control Center" in the "Settings" menu.

You will also notice an informational message discussing an "Error while initializing the sound driver." This is because our remote VNC connections do not currently support sending sound. You should select "Do not show this message again."

Finally, for security we ask that you change your initial password to something new upon first log in. To do so, please click on the bottom left Icon (a gear with a "K" over it), and from that menu choose "Settings" and then "Change Password".

Hopefully, you will be able to feel your way around the computing environment from this point without formal instructions. Most of the commonly used software can be found through their own version of a "Start" menu, invoked by clicking on an icon at the bottom left corner of the desktop (a gear with a "K" over it).

We have set up a few initial folders in your "Home" directory for convenient:

Note: For those familiar with a Unix/Linux operating system, patel2 can be accessed remotely through a terminal style interface using a secure shell (ssh). Files can also be transfered via any secure file transfer program.


Using BlueJ

To facilitate our development of programs in Java, we will be using an integrated Java environment known as BlueJ. On patel2 you can start this program by going to the "K" menu at bottom left, then selecting the "Java" folder, then selecting the "BlueJ" entry. (KDE also adds your most recently used applications to the very top of the "K" menu, so the next time you try it you will also find a listing for BlueJ there). If you have successfully started up BlueJ, you should get a window such as this:

Important note:

The user interface for BlueJ (and KDE as well) assumes that you have a two- or three- button mouse. In particular, it can differentiate between what it considers a "left," "middle," and "right" click. If you indeed have a three-button mouse, the clicks should be interpetted as expected. If you have only a two button mouse, the two buttons are treated as the "left" and "right", and you can simulate a "middle" click by clicking both buttons at once. If you are working on a machine with a single button (e.g., the Mac's in our lecture room!) the behavior is as follows. A standard mouse click will be interpretted as a "left" click. You can simulate a "middle" click by holding down the "option" key on the keyboard as you click, and you can simulate a "right" click by holding down the "apple/command" key while clicking the mouse.

A lengthy tutorial for using BlueJ can be found at www.bluej.org/tutorial/tutorial.pdf. We will work through the use of this software over several class periods.

To start with, we will discuss the following actions:



We will use two examples taken from Ch. 01 of the text, and available in the csa120shared folder under the subdirectory labs/Warmup. Either in class or on your own, we suggest that you go through the text's "Lab Exercise" 2 and 3 from page 59.
Michael Goldwasser
Last modified: Thursday, 05 February 2004