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From: julian@osu-eddie.UUCP (Julian Gomez)
Newsgroups: net.graphics
Subject: Re: Re: XOR cursors
Message-ID: <831@osu-eddie.UUCP>
Date: Tue, 19-Nov-85 14:15:51 EST
Article-I.D.: osu-eddi.831
Posted: Tue Nov 19 14:15:51 1985
Date-Received: Wed, 20-Nov-85 20:31:45 EST
References: <959@turtlevax.UUCP> <4576@alice.UUCP>
Organization: Ohio State Univ., CIS Dept., Cols, Oh.
Lines: 25

> Ken Turkowski says:
> 
> > History: CADTRAK of Sunnyvale is asking big bucks to license the
> > technology that allows non-destructive display of a cursor by means of
> > exclusive-or.  They have a patent dated around 1980.
> > ...
> 
> In general, it IS possible to patent a novel combination of several ideas
> that have been around for a while as long as the combination is
> not obvious.

*** REPLACE THIS LINE WITH YOUR BIT OPERATION ***

A couple of months ago I pointed out that the whole process was
obvious and well known by 1980 (I'd even used it in a couple of
paint programs). The earliest use of XOR in a frame buffer cursor
that I know of was in 1976 on the E&S frame buffer at UofU.  By
1980 I had met a number of people who were doing the same thing
and weren't making any secret of it.
-- 
"If Chaos himself sat umpire, what better could he do?"

	Julian "a tribble took it" Gomez
	Computer Graphics Research Group, The Ohio State University
	{ucbvax,decvax}!cbosg!osu-eddie!julian