Path: utzoo!dciem!king
From: king@dciem.UUCP (Stephen King)
Newsgroups: comp.sys.amiga
Subject: Re: Multisync interlace problem
Message-ID: <2633@dciem.UUCP>
Date: 8 Feb 88 18:56:39 GMT
Article-I.D.: dciem.2633
Posted: Mon Feb  8 13:56:39 1988
References: <683@esunix.UUCP> <2582@swan.ulowell.edu> <40648@sun.uucp>
Reply-To: king@dciem.UUCP (Stephen King)
Distribution: na
Organization: D.C.I.E.M., Toronto, Canada
Lines: 15
Summary: 

In article <40648@sun.uucp> cmcmanis@sun.UUCP (Chuck McManis) writes:
> ...  an even wilder scheme. They said "Gee if on the odd frames we make the
>first horizontal sync pulse half as wide, then the lines from the odd frames
>will appear *between* the lines of the even frames." ...
Not exactly. Horizontal sync pulses are ALWAYS the same width. What changes
is the relationship between H & V sync. NTSC requires 262.5 horizontal lines
per field (525 lines per frame). This means that, during display of field 0,
V sync starts in the middle of the last line. Consequently, for display of
field 1, V sync ends halfway through the first line and starts up again at
the end of the last line. Voila - INTERLACE (no poofs here :-)	...sjk
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