Preemptive threads for SPARC

["Mark_Weiser.PARC" at xerox.com]

The PCR (Portable Common Runtime) package for sparcs provides full
pre-emptive threads for sparcs, including a solution to the blocked on
page-fault problem.  Source by anonymous ftp from arisia.xerox.com,
directory pub, file pcr.tar.Z.  You can look and see how we did it in
there.

This package is in use by hundreds of people running heavily
multi-threaded systems of over a million lines of code, so I think it
works.