Greg Aharonian runs the Internet Patent News Service. He's got a wild
hair about the lack of cited prior art in almost all software patent
filings, and makes a living busting software patents on behalf of
companies that get sued for infringing. He invited commentary from
his newsletter's readership on prior art for preemptive multithreading
and very easily came up with 3 or 4 references to systems published
before Mr. Reiffin's patent was filed (in 1981). One of these earlier
systems was developed by an OS guru who went to Microsoft years ago
and is still there.
I'd say they have nothing much to worry about here.
Keith Dawson email@example.com
Layer of ash separates morning and evening milk.