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Twilight World- NTSC?


Atari_Force
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Every other frame normally starts after the VBLANK at around scanline 285 on PAL or scanline 32 on NTSC. The late frame start on NTSC delays the animation updates so they occur after the beam has already passed. That causes glitches.

 

I tried moving the frame start so that it occurs around scanline 147 by adding a DLI and moving the tick update from VBLANK to this new DLI. That seemed to fix the glitches.

 

twilight-world-ntsc-fix.zip

Edited by Xuel
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Looks like with my fix, the wizards on level three still glitch and the dragon also doesn't draw in time. I'm afraid there just isn't enough off-screen compute time on NTSC to update the screen cleanly with the current rendering framework of the game. Possible solutions would be to double-buffer the screen or reorganize the code to put all of the screen updates together so they're not so spread out.

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On 11/27/2017 at 3:26 AM, Xuel said:

Looks like with my fix, the wizards on level three still glitch and the dragon also doesn't draw in time. I'm afraid there just isn't enough off-screen compute time on NTSC to update the screen cleanly with the current rendering framework of the game. Possible solutions would be to double-buffer the screen or reorganize the code to put all of the screen updates together so they're not so spread out.

Indeed, the patched version on the third level looks like this.

ntsc.png.af4bb6b0959e5b7814c54ce2a4f065c6.png

 

The original version in PAL

pal.png.1683aa53f989512408b5f9aa6ed456db.png

 

 

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