MOTM

Patents are good for 17 years from date of grant (for these. New laws are
different). If there is no patent,
you can 'steal' it. The Moog filter patent was used very successfully
against ARP, SSM (the 2040 chip)
and others.

Since most of these circuits date from the early to mid-70s, the patents
have long expired.

Patents are very interesting. I spent 4 years at Tandy on both the offensive
and defensive ends of patent
litigation (I myself have 9 patents). Patents are scorned only by those that
don't have them :)

True, there are MANY MANY patents that should have never been granted. In
past years, it was almost impossible to
get a patent revoked. Now, with computer searches and 40GB hard drives, you
can get them tossed out. There is
a website somewhere that actually pays serious 'bounties' (like $25,000
cash) if you get certain patents tossed out.

What people forget is how fast technology moves, and how quickly we forget
the state of technology 17 years ago.
Reading patents still valid (say, granted in 1986) seem like total jokes,
because in many cases in TODAY'S world
such-and-such technology is $10 at Wal Mart. But NOT BACK THEN. It's the
BACK THEN that people get all upset over.

Paul S.