Path: utzoo!utgpu!cunews!bnrgate!bwdls58!bwdlh417!dbscoop2
From: dbscoop2@bwdlh417.BNR.CA (Alun Fryer)
Newsgroups: comp.sys.amiga.misc
Subject: Re: ICD Flicker Fixer
Keywords: FLICKER FIXER
Message-ID: <6550@bwdls58.bnr.ca>
Date: 23 Apr 91 13:25:57 GMT
References: <178.280BE812@weyr.FIDONET.ORG> <6515@bwdls58.bnr.ca> <1991Apr19.172421.15923@cbnews.cb.att.com> <1991Apr19.200435.2537@psych.toronto.edu> <m0jUAnZ-000CrzC@reed.edu>
Sender: news@bwdls58.bnr.ca
Reply-To: dbscoop2@bwdlh417.BNR.CA (Alun Fryer)
Distribution: world
Organization: Bell-Northern Research Ltd.
Lines: 55

In article <m0jUAnZ-000CrzC@reed.edu>, kuch@reed.edu writes:
|>Question on flicker boards...the thread, with a bunch of quotes, and
re-quotes
|>has been hard to follow.  The motion artifact problem, when a quickly moving
|>object like the mouse pointer leaves "ghosts" of itself in its wake occurs
|>on which of the following (please post for the record):
|>
|>	A3000 built-in deinterlacer (I never noticed it if it does).
|>
|>	A2320 (same circuitry as A3000 almost) ?
|>
These both have a "Ghost Image" of any fast moving graphics due simply
to the method they use to de-interlace.  Since Denise only updates each
scan line 30 times per second, (once every 2nd frame), each scan line is
displayed for 2 frames.  It works something like this:
On a standard 1084 (no display enhancer): 
		Frame 1: Write line 1,3,5....
		Frame 2: Write line 2,4,6.....
		Frame 3: Write new line 1,3,5....
		Frame 4: Write new line 2,4,6....
				etc..

With the display enhancer:

		1: Write line 1,2,3,4,5....
		2: Write new line 1,3,5... 
			and rewrite old line 2,4,6....
		3: Write new line 2,4,6....
			and rewrite previous line 1,3,5...
				etc..
Anyways, what happens is when you move something quickly, every second
scan line is one frame behind the alternate lines so you get a "Ghost
image".  Its a bit annoying, but I can live with it (It's not as bad as
flicker!).  This problem does not occur in non-interlaced mode, since
each scan line is displayed on every frame.




|>	ICD Flicker Free Video ?

Don't know, but I have been told it behaves similarly to the A2320 & A3000

|>	MicroWay FlickerFlixer ?

Don't know... never seen one.  

|>Please post.
              
Posted.


						- Alun Fryer