I've tried Googling but I've found conflicting answers and the clearest I've
gotten is that the rules for the sandbox an applet runs in varies according
to each browser.

I've read, for example, that applets don't have access to files on the local
file system, but I've used applets that let me upload files to a website.

Where can I find out what the rules about applet sandboxes are?  For
example, if I could have an applet load and save files locally and send
them to a local printer, then I could write a program that I've given to
some people as an applet and it would make updating it much easier.

Yes, I realize an applet reading and writing files and using the printer is
a security risk, but if it's already allowable, then I could use it.  Is
there a good, reliable site with information on this?

Thanks!

Hal