Just see a grey rectangle?
Is Java enabled? Check your web browser settings (advanced).
It may be disabled by some "high security" settings.
Are you using the oldest version of Java (1.0)?
JCM now uses a few Java 1.1 components, which are included in IE5 and NS4.x.
JCM was developed on a PC with 600Mhz processor and 128MB memory
but should work acceptably on much slower computers.
It only uses about 4MB memory for calculations and images (depending on your screen size).
If it's slow, you can adjust parameters by clicking on a control, then clicking elsewhere, instead of dragging.
Really Slow on Unix / Linux?
Probably, you are using Netscape 4.x ?
Netscape's implementation of the Java Virtual Machine
(JVM, see What is Java)
on Unix/Linux platforms is really slow.
So on Unix you are advised to use Netscape 6 (which includes Sun's JVM)
or a java plugin from Sun or Compaq or whoever makes your system.
Alternatively, if you are an "expert" and Sun's JRE (1.1 or later) is already installed on your system,
you can use Sun's java appletviewer to run the model without documentation.
For example type:
Demonstration Scripts not working?
However there is currently a problem with a security exception in Netscape 6 (Sun Java 2).
The html-frame structure is also essential for this communication.
Report other problems
Please let me know, with as much information as possible.
If the model gets stuck, tell me how far it gets,
and check if any errors are reported in the "Java Console".
(view menu in IE, tools menu in Netscape).