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Apple II NTSC emulation
- Subject: Apple II NTSC emulation
- From: vladitx <vladitx@nucleusys.com>
- Date: Wed, 5 Aug 2009 14:15:42 -0700 (PDT)
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I started this quite some time ago and then buried it, but recently
got to it again and today there are first results:
http://softjunk.org/sw/apple2/ra2/files/screenshot/ntsc/
The decoding is done via lookup tables (depth of 2**13 used for the
test images), as was agreed back then with M.J. Mahon. The lookup
tables are generated through I/Q demodulation with asymmetric filters.
Full line NTSC decoding will look bit different (and probably better),
but it's the table approach that is important now.
So, how does it look like? I don't have access to color Apple monitor,
so can't really judge how far it may be. :-) Both in terms of colors
and resolution.
Tint is adjustable, and I guess the Apple II has a noticeable phase
offset due to gate delays, but the images were generated with
"idealistic" zero offset.
Cheers,
-- vladitx