[comp.sys.amiga.hardware] Defeat Interlace Flicker

peterk@cbmger.UUCP (Peter Kittel GERMANY) (05/24/91)

In article <21863@cbmvax.commodore.com> jesup@cbmvax.commodore.com (Randell Jesup) writes:
>  Interlaced video flickers.

Just came across one old idea: There are many people, including myself,
that think that the Amiga interlace flicker is still worse than on a
normal TV, also for comparable display contents. So I suspect from the
beginning that the sync signals produced by the Amiga are not 100 %
appropriate for interlace timing. One proof is very simple: As already
mentioned in the discussion about the flickering half of the 1st scan 
line on the A2320, interlace standard demands that one of the half frames
begins with a half scan line, and the other frame ends with such a half
scan line. As far as I know, this is not so with the Amiga. Plus there
may be several more problems with the vertical sync patterns for the 
two half frames that must be considerable different for odd and even.
I get the impression that those professional genlocks, that also have
plain NTSC (aka interlaced) output, give a much more stable image.

My thoughts behind all these considerations is naturally, perhaps we
could improve the flicker situation drastically "just" by modifying
those sync generators, in worst case through an additional hardware
hack, or in Denise (or ist another Amiga chip?). 

Does anyone know details? (I must admit that I'm also only half-educated
on interlace sync timing.)

-- 
Best regards, Dr. Peter Kittel  // E-Mail to  \\  Only my personal opinions... 
Commodore Frankfurt, Germany  \X/ {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk