The following additions have been made to the course or are currently being worked on. Try them out!!

• The gravity module has been updated. You can now collect east/west trending lines at any north/south location in the survey area. I have added additional targets and included modeling and survey design code appropriate for these new targets. The additional target consists of a vertical mine shaft. Unfortunately, the new modeling and design codes are being provided as Java applets only. I will no longer be producing or supporting the Mathematica or the Matlab scripts.

• Java applets are now available for the all portions of all Modules. I have found some interesting features associated with Java implementation of a variety of browsers. Under Windows95 the Java applets work with both Netscape (3.01+) and Internet Explorer (3.0+). Performance seems to be a bit slower under Netscape than under Internet Explorer, particularly when you vary parameters represented by slider bars. Netscape, however, does a better job of honoring the instantiated sizes of the parameter frames I've generated in these scripts. Netscapes handling of the color maps for these frames, however, leaves much to be desired. Internet Explorer handles the color maps ok, but it doesn't instantiate the frames with the correct size. So, when using Internet Explorer you'll need to manually resize the frames. I have only tested these scripts on a Unix system operating under Linux with Netscape. In this case, the color maps are still screwed up and in addition, the base coordinate system used in drawing to the frames appears to behave oddly. You'll notice that the top quarter of each frame is missing. Resizing the frame does not help. Oh well, hopefully as new versions of the various browsers come out they will converge on their implementation of the Java interpreter.

• I have fixed the large data issue with the magnetics modeling applet. The symptom was that if you inserted large data sets into the text area of the magnetic modeling applet the applet would come up with no data. This took a while to track down and fix, and I have to say I still really don't know why what I did didn't work. I discovered that with large datasets a temporary file that I am writing came up empty. When my CGI script was run outside of the CGI interface everything worked. Although I discovered that the "sed" commands I was using to parse the input data ran exceedingly slow. So, I'm speculating that when interfaced through CGI, that something was timing out and not allowing "sed" to complete its job. I fixed the problem by rewriting this CGI script in PERL. Which seems to work and run much faster. This is something I should probably do for all of the CGI scripts.

• I've figured out how to get the applet frames from disappearing when you resubmit new data sets to a currently running applet. At present, the only applet that has the code fix is the seismic data modeling applet. I will add the fix to all of the other applets.

• All of the notes are complete for all Modules.

• I've discovered that my use of in-line Greek symbols is no longer supported by current versions of Netscape and Internet Explorer. These symbols will show up on your browser page as the name of the Greek letter preceeded by an ampersand sign. I've recently figured out a fix for this problem and will be implementing it soon.

• Interactive, self tests have been added to the Gravity and Resistivity Modules.

• Java Script has been added to the site. The menu bar to the left is created with a cool pirated Java Script implimentation. In addition, Java Script regulated applets have been added to the seismic section to aid in picking and displaying travel times and to a quiz in the Resistivity section. Please NOTE, neither of these latter two implimentations currently work under Internet Explorer (3.0) or Netscape (3.0). They do work under Internet Explorer (4.0+) and Netscape (4.0+).

• I've added additional movies to the seismic module and java applets that allow you to pick first arrival times off of the screen. I have yet to distribute the user generated data bases as anything more than travel times. But, my intent is to generate gif's on the fly of seismic data and allow you to pick the times yourself.

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