There is a demo of the emulator running at:
http://www.ubercomp.com/jslm32/src/
It works much better on Chrome (using a nice terminal emulator that I borrowed from the chromium source tree), but works on Safari and Firefox too.
To run jslm32 on your own machine:
python -m SimpleHTTPServer
Open your browser: http://localhost:8000/src
Click the Start! button.
Enjoy.
Contact: reginaldo at ubercomp dot com