LEGO MINDSTORMS Robots Manual page 211

mThread.interrupt();
}
public void reset() { mComplete = false; mError = false; }
public boolean isComplete() { return mComplete; }
public boolean isError() { return mError; }
public String getLastLine() { return mLastLine; }
}
public class DownloadException
extends IOException {
public DownloadException (String message) { super (message); }
}
}
C
Future Directions
This appendix mentions several interesting technologies related to LEGO robots that didn't make it into the rest of the book. These are things either that weren't quite fully complete as the book
went to press or that aren't entirely relevant to a general book on LEGO robots.
RIS 1.5
The first thing to look for, of course, is RIS 1.5. As of this writing (August 1999), there's been only a whisper of it, an off-hand mention in the discussion forums at the official LEGO
MINDSTORMS web site. It's supposed to be released in the Fall of 1999, but what actually comprises RIS 1.5 is anybody's guess. One person at LEGO technical support did say it is a software-
only upgrade, not a change to the RCX. At this point, though, it's all rumors and speculation; keep your eyes peeled for real announcements.
Java for the RCX
You can program your RCX in C, C++, Smalltalk, Tcl, and Visual Basic; why not Java? The RCXJVM project aims to build a small Java Virtual Machine (JVM) and supporting classes for the
RCX. It's based on a JVM developed for a different 8-bit microcontroller, the Motorola 68HC11. (That JVM reportedly was only 6k, which would certainly fit fine in the RCX's 32K of RAM.)
LEGO Robots as JINI Devices
JINI™ is a Java™-based standard from Sun Microsystems™. The basic premise of JINI is that devices should be able to connect and disconnect from networks seam-
lessly. You should, for example, be able to plug your laptop computer into a hotel network jack somewhere and be able to use the printer, without going through a lot of network configuration
gobbledygook. The network vision extends beyond these traditional devices, however, to things like mobile telephones, pagers, Personal Digital Assistants, and, of course, LEGO robots. A
detailed article on this demonstration (including source code) is here:
http://developer.javasoft.com/developer/technicalArticles/ConsumerProducts/
JavaTanks/Javatanks.html
At one of the keynote speeches for the 1999 JavaOne conference, in fact, a demonstration of JINI included LEGO robots as JINI devices. Unfortunately, JINI doesn't actually run on the RCX. A
proxy system is used instead, such that a JINI proxy runs on a PC, which, in turn, communicates with the robot over the IR link. However, it still makes for an interesting technology blend.
Independent of the JavaOne demonstration, Jan Newmarch has written a JINI tutorial that includes examples with LEGO robots. You can read it for yourself here:
http://pandonia.canberra.edu.au/java/jini/tutorial/jini.xml
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