Article View: comp.sys.mac
Article #40258Re: Inverse video/text
From: Barry Margolin
Date: Mon, 03 Apr 1989 04:11
Date: Mon, 03 Apr 1989 04:11
19 lines
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1335 bytes
Actually, I believe that what was patented was the use of XOR to
display a movable cursor on a raster display. This technique allows a
cursor to be displayed over existing portions of the display without
requiring additional storage for the old contents of the overlaid
area. When the cursor moves you simply XOR it again in the old
location to restore the original contents.
It may also cover things like blinking block cursors. I suspect it
DOESN'T cover the standard Macintosh arrow mouse cursor, since that
displays a black arrow, rather than an inverted arrow. However, it
inverts the border, so that the arrow is still visible on a black
background; I don't know whether this hybrid scheme is covered by the
patent.
Barry Margolin
Thinking Machines Corp.
barmar@think.com
{uunet,harvard}!think!barmar
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!pasteur!ames!think!barmar From: barmar@think.COM (Barry Margolin) Newsgroups: comp.sys.mac Subject: Re: Inverse video/text Message-ID: <38395@think.UUCP> Date: 3 Apr 89 04:11:25 GMT References: <6806@saturn.ucsc.edu> <141200011@cdp> <5894@pdn.paradyne.com> Sender: news@think.UUCP Reply-To: barmar@kulla.think.com.UUCP (Barry Margolin) Organization: Thinking Machines Corporation, Cambridge MA, USA Lines: 19