A google docs link to original scheme manual, in case the site bogs down.
<a href="http://docs.google.com/viewer?url=http%3A%2F%2Frepository.readscheme.org%2Fftp%2Fpapers%2Fai-lab-pubs%2FAIM-349.pdf" rel="nofollow">http://docs.google.com/viewer?url=http%3A%2F%2Frepository.re...</a>