From:	CRDGW2::CRDGW2::MRGATE::"SMTP::CRVAX.SRI.COM::RELAY-INFO-VAX" 20-APR-1991 13:30:35.97
To:	ARISIA::EVERHART
CC:	
Subj:	Re: Multi-session suppoprt

From:	RELAY-INFO-VAX@CRVAX.SRI.COM@SMTP@CRDGW2
To:	Everhart@Arisia@MRGATE

Received:  by crdgw1.ge.com (5.57/GE 1.97)
	 id AA05879; Sat, 20 Apr 91 13:16:12 EDT
Received: From TGV.COM by CRVAX.SRI.COM with TCP; Sat, 20 APR 91 01:53:42 PDT
Date:     Fri, 19 Apr 91 23:31:20 PDT
From: adelman@TGV.COM (Kenneth Adelman)
Reply-To: Adelman@TGV.COM (Kenneth Adelman)
Message-Id: <910419231743.21c00314@TGV.COM>
Subject:  Re: Multi-session suppoprt
To: leichter@lrw.com
Cc: info-vax@sri.com

> The protocol is called TD/SMP (Terminal-Device Session Management Protocol).
> It is patented (US Patent Number 4,791,566 (December 13, 1988)) and, the last
> I heard, DEC was NOT licensing it.  You should think carefully about the legal
> implications before continuing.  (Many people have some completely false ideas
> about patent law.  The fact that you give something away does not give you any
> protection from the patent holder; profit has nothing to do with it.	In fact,
> while it's probably unlikely that DEC would bother to go after you, legally
> they would be entitled to do so even if you just used the infringing "device"
> yourself, and didn't give anyone else copies.)

    Do you have specific citations to cases which back this up?  I'd
be interested in reading them.	The intent of patent law is to grant
an exclusive right to profit from an invention for a period of time in
EXCHANGE for making public the invention.  I've never heard of cases
where non-profit use of a patent without license was successfully
prosecuted.

    There is a whole body of interesting cases involving "abuse of
patent" where the patent holder tries to "expand" the normal patent
protection for other purposes, and some circuit courts have rules that
attempts to do this can invalidate the basic protections granted by
the patent.  These decision seemed to be based on the idea that a
patent is a "bargain with society" and failure to fully disclose the
invention and permit non-profit use can prevent the patent holder from
prosecuting unlicensed for-profit use, because the patent holder has
failed to uphold his side of the bargain.  I've also heard of a
circuit court decision which expanded this "abuse of patent" concept
to "abuse of copyright" to indicate that precautionary copyrights of
proprietary data might be invalid because of the failure to disclose
the proprietary data.

    Of course, when patent law was written I don't think that anyone
dreamed of someone building "machines" to give them away like
public domain software is today.

						    Kenneth Adelman

Disclaimers: I am not a lawyer and don't recommend unlicensed
    not-for-profit use of patents.  Anyone considering such should
    consult a lawyer.