Re: [stella] NTSC/PAL detection

Subject: Re: [stella] NTSC/PAL detection
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Mon, 6 Aug 2001 19:07:26 +0200
> After reading the Stella manual again, I catched my error. You can't
> wait for a new frame, but you signal when a new frame starts. OK, big
> difference here! Next question :o) NTSC needs 40 scan lines for VBLANK
> and PAL needs 48 scan lines for VBLANK. What happens, if you do more
> than 40 scan lines on NTSC, say 48? Does this work? Ignoring color
> differences on NTSC and PAL, is it possible to write a syncronisation
> routine with this for NTSC and PAL? Yes, your are loosing scan lines on
> NTSC etc. But is it?

There is no need for this. Most PAL TVs can handle 60 Hz VCS output
quite nicely. The picture will be vertically centered with black
bars above and below. It's only important that you do 3 uninterrupted
scanlines of VSYNC. And it would be better, if you'd turn on VBLANK
after the last line of display to make sure that the black bars really
are black.

Ciao, Eckhard Stolberg

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